Re: [time-nuts] New NTBW50AA
I did a bit of sleuthing today about my dBc numbers. Looks like my best numbers happened (47.2 and 44.7) when the antenna was on the shortest piece of feed line, maybe 30', right above my room but well under the canopy of trees. Highest dBc I get now is in the low 40's with 150' of feed and the antenna in the clear for the most part. Also when I do the S A S thing, I never see any blue areas which should be in the >40 dBc and I see that number (40-42) all the time with the green sat numbers. What is going on here? Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
R is to read files. I tried all 3 reset (!) commands, warm, cold and hard. (and said 'OH no what have I done) Warm locked in about 3 minutes and cleared the holdover, cold locked in 10 minutes, hard locked in 10 minutes but cleared the lat lon, reset the EL to 10, AMU to 4. I put the lat lon and alt back in and after the almanac came back up in about 16 minutes, everything else remained the same. Seem to have to force LH to stop and re-start each time. I'm looking at the signal strength vs. az/el and I'll let it run for a while. I still hardly ever see much above 43-45 dBc. I have new cable coming, so maybe that will help but I doubt it. I may try the K7KKQ antenna and an amp from mouser. Dave - Original Message - From: James Tucker To: Discussion of precise time and frequency measurement Sent: Friday, September 20, 2013 10:38 PM Subject: Re: [time-nuts] New NTBW50AA LH has provisions for various reset levels; I don't know if they apply to the Nortel. Try 'r', and see where that leads. JimT ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
LH has provisions for various reset levels; I don't know if they apply to the Nortel. Try 'r', and see where that leads. JimT Sent from *my* galaxy (Nexus). On Sep 20, 2013 9:03 PM, "quartz55" wrote: > I'm thinking I was dreaming because it's still at 468, like before. It is > probably from when I was moving the antenna around and didn't turn the unit > off and of course I didn't write it down. > > Still wondering if holdover can be reset without turning it off. > > Happy equinox. > > Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
I'm 1250' ABOVE sea Level. LH currently reports an altitude of -2500'. What's up with this?? Jim On 9/20/2013 7:29 PM, Bob Camp wrote: Hi GPS uses a model of the earth. It calculates position relative to this model. The model does *not* correspond to sea level. It's very common to be driving along the beach and see negative altitude numbers with an honest GPS. If you are located within 100' of sea level, you may see negative altitude from a GPS. In other areas you may of course see significant positive altitudes when sitting on the beach. Bob On Sep 20, 2013, at 7:23 PM, Jim Sanford wrote: Mine insists on determining a negative altitude. sometimes it's called a good position, sometimes not. Eventually, it becomes 'good" even with -altitude! Now I understand why it goes in and out of holdover, but what about the bad altitude?? Jim wb4...@amsat.org On 9/20/2013 6:22 PM, Bob Camp wrote: Hi If the unit is dropping into holdover, something is wrong with the number of sat's it's seeing. If you have saved a location properly, it will only go into holdover when it's got zero sats. If it does not believe it's got a proper location it will drop into holdover when it goes below 4 sats. The number of sats visible isn't what counts here, it's the number that are locked up, above the elevation mask, and above the AMU threshold. Set either the elevation or the AMU to high and you will go in and out of holdover. Bob On Sep 20, 2013, at 2:13 PM, quartz55 wrote: I was thinking of keeping a couple of batterys floated across the supply, since it will run on 24V. I'll have to figure out what I'll need for maybe 2 hours. Not sure what it's drawing now at 30V, but wouldn't be hard to measure. Couple more things. What is the foliage filter and will it work on the Nortel? I keep seeing my holdover going up but haven't seen any sat drop out or yellow light on the front. Is there any way to re-set the holdover without turning the unit off? It's up to 468 now, not sure where it started the other day but probably in the 200's. I may be dreaming too. I've dropped the idea about choke ring or ground planes after reading what I could about it. I may try building my own turnstile antenna (ala K7KKQ) and amp just for fun. Amps are cheap from Mouser and have less than 2 dB NF unlike mine which is 4 dB. Has someone made a DIY helix? I liked the pinwheel antenna but it may be hard to make. Dave - Original Message - From: Charles Steinmetz To: Discussion of precise time and frequency measurement Sent: Friday, September 20, 2013 1:01 PM Subject: Re: [time-nuts] New NTBW50AA Dave wrote: We have plenty outages here, so I may look into a UPS of some sort but I have a rather large generator that I always turn on after about 1/2 hour or so. The UPS is to keep master oscillators (and for some of us, ovenized voltage standards) running uninterrupted from the time of the failure until the generator is running. Best practice is to use a "double conversion" UPS to avoid even a short outage as it kicks in. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
I'm thinking I was dreaming because it's still at 468, like before. It is probably from when I was moving the antenna around and didn't turn the unit off and of course I didn't write it down. Still wondering if holdover can be reset without turning it off. Happy equinox. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi If you have one *good* sat, it should stay out of holdover. Bob On Sep 20, 2013, at 9:01 PM, Paul Berger wrote: > Hi: > > My Nortel unit seems to go into holdover when LH is still reporting one > usable satellite. When doing a survey it would go into holdover below four > because I believe it is doing 3D position samples which would require four. > > On a related note I picked up some 110 pin Z-Pack connectors, that would fit > these units, cheap and I have four extras I don't have any use for and will > offer then here free, one per customer, to the first four people who send me > a private email. If postage is expensive to where you are from eastern > Canada I may ask you to pay for the postage. > > Paul. > > On 9/20/13 7:22 PM, Bob Camp wrote: >> Hi >> >> If the unit is dropping into holdover, something is wrong with the number of >> sat's it's seeing. If you have saved a location properly, it will only go >> into holdover when it's got zero sats. If it does not believe it's got a >> proper location it will drop into holdover when it goes below 4 sats. The >> number of sats visible isn't what counts here, it's the number that are >> locked up, above the elevation mask, and above the AMU threshold. Set either >> the elevation or the AMU to high and you will go in and out of holdover. >> >> Bob >> >> On Sep 20, 2013, at 2:13 PM, quartz55 wrote: >> >>> I was thinking of keeping a couple of batterys floated across the supply, >>> since it will run on 24V. I'll have to figure out what I'll need for maybe >>> 2 hours. Not sure what it's drawing now at 30V, but wouldn't be hard to >>> measure. >>> >>> Couple more things. >>> >>> What is the foliage filter and will it work on the Nortel? >>> >>> I keep seeing my holdover going up but haven't seen any sat drop out or >>> yellow light on the front. Is there any way to re-set the holdover without >>> turning the unit off? It's up to 468 now, not sure where it started the >>> other day but probably in the 200's. I may be dreaming too. >>> >>> I've dropped the idea about choke ring or ground planes after reading what >>> I could about it. I may try building my own turnstile antenna (ala K7KKQ) >>> and amp just for fun. Amps are cheap from Mouser and have less than 2 dB >>> NF unlike mine which is 4 dB. Has someone made a DIY helix? I liked the >>> pinwheel antenna but it may be hard to make. >>> >>> Dave >>> - Original Message - >>> From: Charles Steinmetz >>> To: Discussion of precise time and frequency measurement >>> Sent: Friday, September 20, 2013 1:01 PM >>> Subject: Re: [time-nuts] New NTBW50AA >>> >>> >>> Dave wrote: >>> >>>> We have plenty outages here, so I may look into a UPS of some sort >>>> but I have a rather large generator that I always turn on after >>>> about 1/2 hour or so. >>> The UPS is to keep master oscillators (and for some of us, ovenized >>> voltage standards) running uninterrupted from the time of the failure >>> until the generator is running. Best practice is to use a "double >>> conversion" UPS to avoid even a short outage as it kicks in. >>> >>> Best regards, >>> >>> Charles >>> ___ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi: My Nortel unit seems to go into holdover when LH is still reporting one usable satellite. When doing a survey it would go into holdover below four because I believe it is doing 3D position samples which would require four. On a related note I picked up some 110 pin Z-Pack connectors, that would fit these units, cheap and I have four extras I don't have any use for and will offer then here free, one per customer, to the first four people who send me a private email. If postage is expensive to where you are from eastern Canada I may ask you to pay for the postage. Paul. On 9/20/13 7:22 PM, Bob Camp wrote: Hi If the unit is dropping into holdover, something is wrong with the number of sat's it's seeing. If you have saved a location properly, it will only go into holdover when it's got zero sats. If it does not believe it's got a proper location it will drop into holdover when it goes below 4 sats. The number of sats visible isn't what counts here, it's the number that are locked up, above the elevation mask, and above the AMU threshold. Set either the elevation or the AMU to high and you will go in and out of holdover. Bob On Sep 20, 2013, at 2:13 PM, quartz55 wrote: I was thinking of keeping a couple of batterys floated across the supply, since it will run on 24V. I'll have to figure out what I'll need for maybe 2 hours. Not sure what it's drawing now at 30V, but wouldn't be hard to measure. Couple more things. What is the foliage filter and will it work on the Nortel? I keep seeing my holdover going up but haven't seen any sat drop out or yellow light on the front. Is there any way to re-set the holdover without turning the unit off? It's up to 468 now, not sure where it started the other day but probably in the 200's. I may be dreaming too. I've dropped the idea about choke ring or ground planes after reading what I could about it. I may try building my own turnstile antenna (ala K7KKQ) and amp just for fun. Amps are cheap from Mouser and have less than 2 dB NF unlike mine which is 4 dB. Has someone made a DIY helix? I liked the pinwheel antenna but it may be hard to make. Dave - Original Message - From: Charles Steinmetz To: Discussion of precise time and frequency measurement Sent: Friday, September 20, 2013 1:01 PM Subject: Re: [time-nuts] New NTBW50AA Dave wrote: We have plenty outages here, so I may look into a UPS of some sort but I have a rather large generator that I always turn on after about 1/2 hour or so. The UPS is to keep master oscillators (and for some of us, ovenized voltage standards) running uninterrupted from the time of the failure until the generator is running. Best practice is to use a "double conversion" UPS to avoid even a short outage as it kicks in. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi GPS uses a model of the earth. It calculates position relative to this model. The model does *not* correspond to sea level. It's very common to be driving along the beach and see negative altitude numbers with an honest GPS. If you are located within 100' of sea level, you may see negative altitude from a GPS. In other areas you may of course see significant positive altitudes when sitting on the beach. Bob On Sep 20, 2013, at 7:23 PM, Jim Sanford wrote: > Mine insists on determining a negative altitude. sometimes it's called a > good position, sometimes not. Eventually, it becomes 'good" even with > -altitude! > > Now I understand why it goes in and out of holdover, but what about the bad > altitude?? > Jim > wb4...@amsat.org > > On 9/20/2013 6:22 PM, Bob Camp wrote: >> Hi >> >> If the unit is dropping into holdover, something is wrong with the number of >> sat's it's seeing. If you have saved a location properly, it will only go >> into holdover when it's got zero sats. If it does not believe it's got a >> proper location it will drop into holdover when it goes below 4 sats. The >> number of sats visible isn't what counts here, it's the number that are >> locked up, above the elevation mask, and above the AMU threshold. Set either >> the elevation or the AMU to high and you will go in and out of holdover. >> >> Bob >> >> On Sep 20, 2013, at 2:13 PM, quartz55 wrote: >> >>> I was thinking of keeping a couple of batterys floated across the supply, >>> since it will run on 24V. I'll have to figure out what I'll need for maybe >>> 2 hours. Not sure what it's drawing now at 30V, but wouldn't be hard to >>> measure. >>> >>> Couple more things. >>> >>> What is the foliage filter and will it work on the Nortel? >>> >>> I keep seeing my holdover going up but haven't seen any sat drop out or >>> yellow light on the front. Is there any way to re-set the holdover without >>> turning the unit off? It's up to 468 now, not sure where it started the >>> other day but probably in the 200's. I may be dreaming too. >>> >>> I've dropped the idea about choke ring or ground planes after reading what >>> I could about it. I may try building my own turnstile antenna (ala K7KKQ) >>> and amp just for fun. Amps are cheap from Mouser and have less than 2 dB >>> NF unlike mine which is 4 dB. Has someone made a DIY helix? I liked the >>> pinwheel antenna but it may be hard to make. >>> >>> Dave >>> - Original Message - >>> From: Charles Steinmetz >>> To: Discussion of precise time and frequency measurement >>> Sent: Friday, September 20, 2013 1:01 PM >>> Subject: Re: [time-nuts] New NTBW50AA >>> >>> >>> Dave wrote: >>> >>>> We have plenty outages here, so I may look into a UPS of some sort >>>> but I have a rather large generator that I always turn on after >>>> about 1/2 hour or so. >>> The UPS is to keep master oscillators (and for some of us, ovenized >>> voltage standards) running uninterrupted from the time of the failure >>> until the generator is running. Best practice is to use a "double >>> conversion" UPS to avoid even a short outage as it kicks in. >>> >>> Best regards, >>> >>> Charles >>> ___ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Mine insists on determining a negative altitude. sometimes it's called a good position, sometimes not. Eventually, it becomes 'good" even with -altitude! Now I understand why it goes in and out of holdover, but what about the bad altitude?? Jim wb4...@amsat.org On 9/20/2013 6:22 PM, Bob Camp wrote: Hi If the unit is dropping into holdover, something is wrong with the number of sat's it's seeing. If you have saved a location properly, it will only go into holdover when it's got zero sats. If it does not believe it's got a proper location it will drop into holdover when it goes below 4 sats. The number of sats visible isn't what counts here, it's the number that are locked up, above the elevation mask, and above the AMU threshold. Set either the elevation or the AMU to high and you will go in and out of holdover. Bob On Sep 20, 2013, at 2:13 PM, quartz55 wrote: I was thinking of keeping a couple of batterys floated across the supply, since it will run on 24V. I'll have to figure out what I'll need for maybe 2 hours. Not sure what it's drawing now at 30V, but wouldn't be hard to measure. Couple more things. What is the foliage filter and will it work on the Nortel? I keep seeing my holdover going up but haven't seen any sat drop out or yellow light on the front. Is there any way to re-set the holdover without turning the unit off? It's up to 468 now, not sure where it started the other day but probably in the 200's. I may be dreaming too. I've dropped the idea about choke ring or ground planes after reading what I could about it. I may try building my own turnstile antenna (ala K7KKQ) and amp just for fun. Amps are cheap from Mouser and have less than 2 dB NF unlike mine which is 4 dB. Has someone made a DIY helix? I liked the pinwheel antenna but it may be hard to make. Dave - Original Message - From: Charles Steinmetz To: Discussion of precise time and frequency measurement Sent: Friday, September 20, 2013 1:01 PM Subject: Re: [time-nuts] New NTBW50AA Dave wrote: We have plenty outages here, so I may look into a UPS of some sort but I have a rather large generator that I always turn on after about 1/2 hour or so. The UPS is to keep master oscillators (and for some of us, ovenized voltage standards) running uninterrupted from the time of the failure until the generator is running. Best practice is to use a "double conversion" UPS to avoid even a short outage as it kicks in. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi If the unit is dropping into holdover, something is wrong with the number of sat's it's seeing. If you have saved a location properly, it will only go into holdover when it's got zero sats. If it does not believe it's got a proper location it will drop into holdover when it goes below 4 sats. The number of sats visible isn't what counts here, it's the number that are locked up, above the elevation mask, and above the AMU threshold. Set either the elevation or the AMU to high and you will go in and out of holdover. Bob On Sep 20, 2013, at 2:13 PM, quartz55 wrote: > I was thinking of keeping a couple of batterys floated across the supply, > since it will run on 24V. I'll have to figure out what I'll need for maybe 2 > hours. Not sure what it's drawing now at 30V, but wouldn't be hard to > measure. > > Couple more things. > > What is the foliage filter and will it work on the Nortel? > > I keep seeing my holdover going up but haven't seen any sat drop out or > yellow light on the front. Is there any way to re-set the holdover without > turning the unit off? It's up to 468 now, not sure where it started the > other day but probably in the 200's. I may be dreaming too. > > I've dropped the idea about choke ring or ground planes after reading what I > could about it. I may try building my own turnstile antenna (ala K7KKQ) and > amp just for fun. Amps are cheap from Mouser and have less than 2 dB NF > unlike mine which is 4 dB. Has someone made a DIY helix? I liked the > pinwheel antenna but it may be hard to make. > > Dave > - Original Message - > From: Charles Steinmetz > To: Discussion of precise time and frequency measurement > Sent: Friday, September 20, 2013 1:01 PM > Subject: Re: [time-nuts] New NTBW50AA > > > Dave wrote: > >> We have plenty outages here, so I may look into a UPS of some sort >> but I have a rather large generator that I always turn on after >> about 1/2 hour or so. > > The UPS is to keep master oscillators (and for some of us, ovenized > voltage standards) running uninterrupted from the time of the failure > until the generator is running. Best practice is to use a "double > conversion" UPS to avoid even a short outage as it kicks in. > > Best regards, > > Charles > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
I was thinking of keeping a couple of batterys floated across the supply, since it will run on 24V. I'll have to figure out what I'll need for maybe 2 hours. Not sure what it's drawing now at 30V, but wouldn't be hard to measure. Couple more things. What is the foliage filter and will it work on the Nortel? I keep seeing my holdover going up but haven't seen any sat drop out or yellow light on the front. Is there any way to re-set the holdover without turning the unit off? It's up to 468 now, not sure where it started the other day but probably in the 200's. I may be dreaming too. I've dropped the idea about choke ring or ground planes after reading what I could about it. I may try building my own turnstile antenna (ala K7KKQ) and amp just for fun. Amps are cheap from Mouser and have less than 2 dB NF unlike mine which is 4 dB. Has someone made a DIY helix? I liked the pinwheel antenna but it may be hard to make. Dave - Original Message - From: Charles Steinmetz To: Discussion of precise time and frequency measurement Sent: Friday, September 20, 2013 1:01 PM Subject: Re: [time-nuts] New NTBW50AA Dave wrote: >We have plenty outages here, so I may look into a UPS of some sort >but I have a rather large generator that I always turn on after >about 1/2 hour or so. The UPS is to keep master oscillators (and for some of us, ovenized voltage standards) running uninterrupted from the time of the failure until the generator is running. Best practice is to use a "double conversion" UPS to avoid even a short outage as it kicks in. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Dave wrote: We have plenty outages here, so I may look into a UPS of some sort but I have a rather large generator that I always turn on after about 1/2 hour or so. The UPS is to keep master oscillators (and for some of us, ovenized voltage standards) running uninterrupted from the time of the failure until the generator is running. Best practice is to use a "double conversion" UPS to avoid even a short outage as it kicks in. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
I may also look into a DIY choke ring for my antenna. With the large pole I have now, it will be no problem to put a rather large ground plane under the antenna if that will help. I'll do some searching on that. I'll keep the thing running, but I may have to switch it at some point if I get a smaller PS. We have plenty outages here, so I may look into a UPS of some sort but I have a rather large generator that I always turn on after about 1/2 hour or so. 80% through the 48 hour survey. I also ordered 150' of RG-11/underground. Thanks, Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi There is no instruction booklet for the NTBW50's and LH. The program is targeted at a TBolt. I think it's great that it happens to work at all for the NTBW50. The stuff about the filter settings has been noted by and posted by several members here on the list. I've seen it on my units here. Setting the elevation mask on any of these units can be done from AMU plots. The gottcha there is that multi path issues will cut in before the signal strength drops off. You want to set it a bit higher than the drop off point. Multipath can be a much larger issue than simple signal to noise. It's the path delay in multi path that's the problem. The sat's are all on the same frequency. However they are moving at a very high rate of speed. That creates a doppler shift in the frequency. You have to track out the doppler before you can even receive the signal. It's also why you can't use the GPS frequency directly as a reference for the GPSDO. Weather the shift is big enough to matter is indeed a matter of conjecture. Without actual filter data, there's no way to really know. As you move the antenna around remember that keeping the GPSDO on power is the main goal. You don't have to keep it connected to an antenna as you relocate, but don't take the OCXO off power. They very much prefer to be run continuously. Bob On Sep 19, 2013, at 10:32 PM, quartz55 wrote: > In the Trimble NTBW50 (and Trimble made clones) you can run the auto cal via > LH. The sensitivity is calculated and may appear to change. The settings can > not be saved in flash / eeprom. They do not persist across multiple reboots. > There is no evidence that the NTBW50 actually uses the changed settings. > > Switching elevation masks, changing AMU limits, works with both units. These > changes do save to flash / eeprom on both units. They persist across multiple > reboots on both. The do impact the way both units function. > > Bob, I suppose you came across this by experimentation, not by any > instruction booklet? I guess we're on our own here with the Nortel units. > How about Mark's (I think) suggestion to "set the EL mask to a low value (F E > 0), clear the signal data (S A C) let the unit run for a day or so, then do > the osc autotune (&A). This will set the elevation mask to a level that > matches what your antenna can see. Or you can check the elevation plot (S A > E) and see where the tick mark shows the signal level dropping off and enter > that value manually." > > My guess is that the antenna you have is virtually identical to the Lucent 26 > db gain device. I doubt that the cost of getting one is worth the money. If > you want a better antenna, go for one of the $300 - $500 choke ring antennas. > You will also need a bias Tee (they mostly run on 12 volts), but it's often > included. > > Well, that's not going to happen, the $3-500 anyhow. I was also thinking > about the filter, aren't all the L1 sats on the same freq, so there shouldn't > be any phase difference with respect to the sats, but I may be way off base > here. > > I found a nice 15' locust log today that's about 6-8" dia. that I can strap > to one of the fence posts and get rid of the 3/4" EMT. Wife likes it too > because it looks 'rustic'. Cool. > > Thanks, Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
In the Trimble NTBW50 (and Trimble made clones) you can run the auto cal via LH. The sensitivity is calculated and may appear to change. The settings can not be saved in flash / eeprom. They do not persist across multiple reboots. There is no evidence that the NTBW50 actually uses the changed settings. Switching elevation masks, changing AMU limits, works with both units. These changes do save to flash / eeprom on both units. They persist across multiple reboots on both. The do impact the way both units function. Bob, I suppose you came across this by experimentation, not by any instruction booklet? I guess we're on our own here with the Nortel units. How about Mark's (I think) suggestion to "set the EL mask to a low value (F E 0), clear the signal data (S A C) let the unit run for a day or so, then do the osc autotune (&A). This will set the elevation mask to a level that matches what your antenna can see. Or you can check the elevation plot (S A E) and see where the tick mark shows the signal level dropping off and enter that value manually." My guess is that the antenna you have is virtually identical to the Lucent 26 db gain device. I doubt that the cost of getting one is worth the money. If you want a better antenna, go for one of the $300 - $500 choke ring antennas. You will also need a bias Tee (they mostly run on 12 volts), but it's often included. Well, that's not going to happen, the $3-500 anyhow. I was also thinking about the filter, aren't all the L1 sats on the same freq, so there shouldn't be any phase difference with respect to the sats, but I may be way off base here. I found a nice 15' locust log today that's about 6-8" dia. that I can strap to one of the fence posts and get rid of the 3/4" EMT. Wife likes it too because it looks 'rustic'. Cool. Thanks, Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi With a Trimble TBolt, when you do an auto-cal it comes up with a sensitivity of the OCXO, and modifies the filter (as in the PID control loop filter) coefficients. You can then save them to the eeprom / flash in the TBolt. The settings persist across multiple reboots. The settings do impact the way the TBolt functions. This allows you to use OCXO's with different sensitivities (and even control polarity) in the TBolt. In the Trimble NTBW50 (and Trimble made clones) you can run the auto cal via LH. The sensitivity is calculated and may appear to change. The settings can not be saved in flash / eeprom. They do not persist across multiple reboots. There is no evidence that the NTBW50 actually uses the changed settings. Switching elevation masks, changing AMU limits, works with both units. These changes do save to flash / eeprom on both units. They persist across multiple reboots on both. The do impact the way both units function. - My guess is that the antenna you have is virtually identical to the Lucent 26 db gain device. I doubt that the cost of getting one is worth the money. If you want a better antenna, go for one of the $300 - $500 choke ring antennas. You will also need a bias Tee (they mostly run on 12 volts), but it's often included. Enjoy! Bob On Sep 19, 2013, at 9:40 AM, "quartz55" wrote: > Thanks Bob, Charles, > > Well, here's my plan. Get a single piece of RG-11 direct burial. Get a more > stable post for the antenna and perhaps a bit taller. Keep my eye out for a > different antenna, right now they seem to be going for $50 and up for the 26 > dB versions, I could contact RDR, but I didn't see anything on his site about > other antennas. Yes, this is no high RF area except when maybe I turn on the > 170 W 2M brick and that's nothing, I saw that thread about filters in the > antenna. Finish this 48 hour survey and get these other things done and then > do a 72 hour survey. Let it run for months and see where we are. Get a > smaller switching type power supply. > > I figured nothing was broken or not working right. > > Bob, are you saying playing with the masks TC, gain and other stuff in LH > does nothing to the NTBW50AA? It just affects how LH looks on my computer > screen and I'm really not changing anything of how the Nortel works? > > Thanks, > Dave > - Original Message - > From: Bob Camp > To: Discussion of precise time and frequency measurement > Sent: Thursday, September 19, 2013 7:23 AM > Subject: Re: [time-nuts] New NTBW50AA > > > HI > > What can be said with reasonable confidence: > > 1) The unit isn't broken and it does not need to go back to RDR under their > 30 day return policy. > 2) The OCXO isn't broken and it does not need to be replaced. > 3) The unit is functioning ok, but probably not as good as it could. > 4) Without comparison to an independent standard, there's no way to know how > well it is or isn't doing. > > Bob > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Thanks Bob, Charles, Well, here's my plan. Get a single piece of RG-11 direct burial. Get a more stable post for the antenna and perhaps a bit taller. Keep my eye out for a different antenna, right now they seem to be going for $50 and up for the 26 dB versions, I could contact RDR, but I didn't see anything on his site about other antennas. Yes, this is no high RF area except when maybe I turn on the 170 W 2M brick and that's nothing, I saw that thread about filters in the antenna. Finish this 48 hour survey and get these other things done and then do a 72 hour survey. Let it run for months and see where we are. Get a smaller switching type power supply. I figured nothing was broken or not working right. Bob, are you saying playing with the masks TC, gain and other stuff in LH does nothing to the NTBW50AA? It just affects how LH looks on my computer screen and I'm really not changing anything of how the Nortel works? Thanks, Dave - Original Message - From: Bob Camp To: Discussion of precise time and frequency measurement Sent: Thursday, September 19, 2013 7:23 AM Subject: Re: [time-nuts] New NTBW50AA HI What can be said with reasonable confidence: 1) The unit isn't broken and it does not need to go back to RDR under their 30 day return policy. 2) The OCXO isn't broken and it does not need to be replaced. 3) The unit is functioning ok, but probably not as good as it could. 4) Without comparison to an independent standard, there's no way to know how well it is or isn't doing. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
HI What can be said with reasonable confidence: 1) The unit isn't broken and it does not need to go back to RDR under their 30 day return policy. 2) The OCXO isn't broken and it does not need to be replaced. 3) The unit is functioning ok, but probably not as good as it could. 4) Without comparison to an independent standard, there's no way to know how well it is or isn't doing. Bob On Sep 18, 2013, at 10:44 PM, Charles Steinmetz wrote: > Dave wrote: > >> You didn't say, but I get the feeling maybe I should be getting smaller ppt >> numbers? When you say noisy, is high ppt generally a result of excess >> noise (front end NF)? > > Hard to say about the ppt numbers -- my TBolts give somewhat lower numbers > than you are getting, but they use different OCXOs with different > phaselocking circuitry, so I can't say what would be considered normal for > the model you have. Also, as several have said already, the GPSDO is > measuring itself with itself (no independent reference), so its proclamations > need to be taken with more than some caution. > > Excess noise on the GPS signals (from whatever cause) causes timing errors in > the GPS, which makes the GPS think the oscillator needs correction, which > leads to DAC adjustments that aren't necessary. But if you are seeing at > least some numbers in the 50 dBc and higer range, there is nothing further > you can do in this regard. (Well, if the model you have supports it, you can > set a "signal level" mask that will exclude satellites with signals below a > dBc threshold of your choice. As with the elevation mask, if you get too > aggressive you may force the unit into holdover when there are a few OK but > not great signals.) > > As we all have said repeatedly, you need a good, accurate survey. Also, it > is the nature of crystal oscillators that when they are disturbed (turned off > and back on, frequency adjusted, handling/moving, fast temperature changes, > etc., etc.) that they take time to settle back down -- often months. Now > that you have a permanent antenna location, do a precision survey, SAVE IT, > then let the unit sit undisturbed for several months and see where you are. > > You are certainly in the ballpark -- there are clearly no gross problems. > > Bob presumably knows more than I do about non-TBolt Trimbles (since I know > nothing about them). If he says you can't adjust the TC and "gain" I'd be > inclined to believe him. (And if you can't adjust the "gain," there is no > point in measuring the EFC characteristics of the OCXO, except for curiosity.) > >> The antenna is a Lucent PCTEL "GPS-TMG-HR-26N, High Rejection 26dB With >> Enhanced Narrow Band Filtering", apparently for high RF environments, only >> one I've got or tried > > You may have read on another thread about narrow bandpass filters tending to > have rising group delay at the passband edges. An antenna with "Enhanced > Narrow Band Filtering" very likely has more group delay error than one with > more gentle filtering, so it is possible that satellites with high doppler > shifts are causing the GPS timing solution to shift around more than it would > with a different antenna. The one you have is presumably good enough for > cell timing, since that is what it was designed for. The question is whether > the lower group delay of an antenna without "Enhanced Narrow Band Filtering" > would be enough better that you could tell. Without measuring the filters, > we can't really predict what to expect. You might ask the seller if he would > exchange your antenna for one that doesn't have the extra filtering. You > almost certainly don't need it in your rural location, and an antenna without > it would at least not be any worse, all else equal. > > Best regards, > > Charles > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Dave wrote: You didn't say, but I get the feeling maybe I should be getting smaller ppt numbers? When you say noisy, is high ppt generally a result of excess noise (front end NF)? Hard to say about the ppt numbers -- my TBolts give somewhat lower numbers than you are getting, but they use different OCXOs with different phaselocking circuitry, so I can't say what would be considered normal for the model you have. Also, as several have said already, the GPSDO is measuring itself with itself (no independent reference), so its proclamations need to be taken with more than some caution. Excess noise on the GPS signals (from whatever cause) causes timing errors in the GPS, which makes the GPS think the oscillator needs correction, which leads to DAC adjustments that aren't necessary. But if you are seeing at least some numbers in the 50 dBc and higer range, there is nothing further you can do in this regard. (Well, if the model you have supports it, you can set a "signal level" mask that will exclude satellites with signals below a dBc threshold of your choice. As with the elevation mask, if you get too aggressive you may force the unit into holdover when there are a few OK but not great signals.) As we all have said repeatedly, you need a good, accurate survey. Also, it is the nature of crystal oscillators that when they are disturbed (turned off and back on, frequency adjusted, handling/moving, fast temperature changes, etc., etc.) that they take time to settle back down -- often months. Now that you have a permanent antenna location, do a precision survey, SAVE IT, then let the unit sit undisturbed for several months and see where you are. You are certainly in the ballpark -- there are clearly no gross problems. Bob presumably knows more than I do about non-TBolt Trimbles (since I know nothing about them). If he says you can't adjust the TC and "gain" I'd be inclined to believe him. (And if you can't adjust the "gain," there is no point in measuring the EFC characteristics of the OCXO, except for curiosity.) The antenna is a Lucent PCTEL "GPS-TMG-HR-26N, High Rejection 26dB With Enhanced Narrow Band Filtering", apparently for high RF environments, only one I've got or tried You may have read on another thread about narrow bandpass filters tending to have rising group delay at the passband edges. An antenna with "Enhanced Narrow Band Filtering" very likely has more group delay error than one with more gentle filtering, so it is possible that satellites with high doppler shifts are causing the GPS timing solution to shift around more than it would with a different antenna. The one you have is presumably good enough for cell timing, since that is what it was designed for. The question is whether the lower group delay of an antenna without "Enhanced Narrow Band Filtering" would be enough better that you could tell. Without measuring the filters, we can't really predict what to expect. You might ask the seller if he would exchange your antenna for one that doesn't have the extra filtering. You almost certainly don't need it in your rural location, and an antenna without it would at least not be any worse, all else equal. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi 1) Have you done a 3 day long survey at any of the locations? You need to do that to get the errors down. 2) Fiddling with the gain and filter settings on a NTBW50 isn't useful. The unit does *not* work the same way as a TBolt. Just leave them alone. 3) Because of the way the uint works there is *no* way to translate the LH display to frequency stability. 4) The OCXO in that unit is at least as good as a typical MV89. Since you have no way to "tune" the unit, replacing the OCXO is not a good idea. Also you may have to buy (and run long term ADEV tests on) a dozen MV89's before you get a "good" one. If you want to check the *stability* of the GSPDO, get a cheap Rb. That's the *only* way to know what's going on. There is no display / measurement / technique that will answer the question looking at the GPSDO alone. Bob On Sep 18, 2013, at 10:11 AM, quartz55 wrote: > Moved antenna to fence line on a 10' emt. Nothing much seems to change no > matter what I do, so I guess this is what I'm locked into unless I start > getting carried away. I still get generally about a 400 ppt swing with the > OSC, about 20 ns swing with the PPS and the other things are just what they > are. Different filters and surveys don't seem to change anything that I've > seen. I like the antenna better at the fence. but I had to add another 30' > of RG-6. I have about 100' of FSJ4-50B that I have no use for right now, but > I doubt that will do anything for me. > http://i251.photobucket.com/albums/gg287/DogTi/time/20139-181346_zps31fb89be.jpg > > Is this acceptable? From what I deduce, I can expect to get accuracy of > +-0.2 Hz at 1GHz? I was hoping for another decimal. This should be plenty > good to get mHz accuracy at 100 MHz if I can even measure that using SpecLab. > Seems to me Arthur was getting much smaller swings on his ppt with his older > Nortel. > > I did figure out the temp thing and found a link where it's explained, but I > have a new chip coming and expect to change it, but I doubt if anything will > change except the reported temp will most likely track to less than 1° C > unlike it's doing now. > > Would it be worth looking into the MV89A OCXO as a replacement to get better > ppt? I haven't done any looking into my OCXO yet to see what it's spec sheet > may be. > > Still waiting on a chip inductor that I messed up in the TS-2000 so I can get > the XRef working. > > Dave > N3DT > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Thanks Charles, I have tried the &a command and that is where LH put the numbers, TC from 100 to 500, Damp from 1.2 (that's how it came) to 1.0, and it changed the gain from 1.2 to 1.403. I could certainly try playing with the DAC voltage. I haven't written anything to the prom yet, I think, when I turn the unit off and back on it seems to revert to where it was when I got it, but that's only been a few times and for a few minutes, it's been on nearly since I got the antenna installed on Sep 9, or 9 days. I haven't done a precision survey at this location either, but it didn't seem to make any difference at the other locations. As far as dBc, I've seen numbers in the 50's at this location and I don't think I've seen that before, but nothing scientific about any of the locations or numbers. This location sees to the east and west probably better than the others, south should be about the same. Actually right now I'm seeing 2 in the 60's and one at 71.5. I wasn't going to change the OCXO willy-nilly, I'll have to explore this one first. I'll see if I can find any info on this OCXO. The antenna is a Lucent PCTEL "GPS-TMG-HR-26N, High Rejection 26dB With Enhanced Narrow Band Filtering", apparently for high RF environments, only one I've got or tried, it came with the Nortel from RDR. About 130' of RG-6 and with the 26dB gain and a 4 dB noise figure, it's probably swamping any loss in the cable or NF of the RX. You didn't say, but I get the feeling maybe I should be getting smaller ppt numbers? When you say noisy, is high ppt generally a result of excess noise (front end NF)? When I get a chance I'll play with the DAC voltage. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
I still get generally about a 400 ppt swing with the OSC, about 20 ns swing with the PPS and the other things are just what they are. Different filters and surveys don't seem to change anything that I've seen. * * * Is this acceptable? You seem to have a reasonably decent view of the sky, judging by the numbers of satellites you are able to track, but the signal quality is lower than I expect (note: my only Trimble GPSDO experience is with TBolts). I'd expect the signal reports to be mostly from 40 dBc upwards, while yours run from low 30s to barely 40 (IIRC, this hasn't changed materially as you've moved the antenna multiple times). Your results look consistent with those signal readings. I don't recall -- have you tried a different antenna? It's also possible that the front end in that particular GPS is noisier than the TBolts I'm familiar with. Also, I see that the oscillator loop gain is set for 1.4 Hz/v. I have no idea what is normal for the OCXOs used in that unit. Have you verified this yourself? (Turn disciplining off, then manually run the DAC voltage up and down while watching the frequency on a counter.) Lowering the GPSDO loop gain may improve matters. Or not. (IIRC, this may mean setting "gain" to a higher number -- the "gain" does not SET the loop gain at that value, it tells the digital loop "expect the oscillator to have this EFC characteristic.") I did figure out the temp thing and found a link where it's explained, but I have a new chip coming and expect to change it, but I doubt if anything will change except the reported temp will most likely track to less than 1° C unlike it's doing now. That would be my expectation, too. Would it be worth looking into the MV89A OCXO as a replacement to get better ppt? I haven't done any looking into my OCXO yet to see what it's spec sheet may be. That depends on whether or not the remaining errors you are seeing are attributable to the oscillator. The remaining errors can be classed broadly as (i) noisy/wandering OCXO, and (ii) adjustments to the DAC that the GPS thinks it should make. In your case, they look more like class (ii) than class (i) to me. Before you switch out the OXCO, let the crystal that is in the unit now settle down for a few months of uninterrupted running. The class (i) errors should go down by themselves. If the errors you see do not go down, it is more evidence that your limitation is noise in the GPS, not the OCXO. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Moved antenna to fence line on a 10' emt. Nothing much seems to change no matter what I do, so I guess this is what I'm locked into unless I start getting carried away. I still get generally about a 400 ppt swing with the OSC, about 20 ns swing with the PPS and the other things are just what they are. Different filters and surveys don't seem to change anything that I've seen. I like the antenna better at the fence. but I had to add another 30' of RG-6. I have about 100' of FSJ4-50B that I have no use for right now, but I doubt that will do anything for me. http://i251.photobucket.com/albums/gg287/DogTi/time/20139-181346_zps31fb89be.jpg Is this acceptable? From what I deduce, I can expect to get accuracy of +-0.2 Hz at 1GHz? I was hoping for another decimal. This should be plenty good to get mHz accuracy at 100 MHz if I can even measure that using SpecLab. Seems to me Arthur was getting much smaller swings on his ppt with his older Nortel. I did figure out the temp thing and found a link where it's explained, but I have a new chip coming and expect to change it, but I doubt if anything will change except the reported temp will most likely track to less than 1° C unlike it's doing now. Would it be worth looking into the MV89A OCXO as a replacement to get better ppt? I haven't done any looking into my OCXO yet to see what it's spec sheet may be. Still waiting on a chip inductor that I messed up in the TS-2000 so I can get the XRef working. Dave N3DT ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Don, Thanks for the suggestion! I have no doubt that you are correct and especially so at the moment of any "strike" or discharge. But these rods cover an area approximately 200 by 500 ft. and I don't find heavy cable "practical!" Feedline varies from the RG-58 you would expect to 7/8 inch Andrew (350'). Lee - Original Message - From: "Don Latham" To: "Discussion of precise time and frequency measurement" Sent: Sunday, September 15, 2013 3:54 PM Subject: Re: [time-nuts] New NTBW50AA Lee, if I can make a couple of comments, first, you can have large voltage differences among your 23 "ground" rods, depending on the ground terminus of the lightning strokes. Second, antennae and feed lines that do not attract lightning due to being "hidden" can still be subject to large induced voltages. I'd suggest all the ground rods and antenna bases be connected directly with large cable so they are all truly at the same ground potential... Don Lee Mushel Lightning is certainly one of Old Mother Nature's principal weapons as well as being extremely unpredictable. My House/Shack is on the side of a hill with the Antenna Farm on top of the hill about 120 yds away with an additional 30 ft. of elevation. There is a metal "lightning rod" extending high enough to provide a "cone of protection" for the house and is grounded directly. And there are five other metal antennas on that roof, two to a separate ground and three to still another which is close to the shack "ground field" which is three additional ground rods. All ground rods I mention are the standard 8 ft. copper plated steel items. Each of five antennas in the antenna field also have individual ground rods and I guess if you follow the cable shields you could say that they are all connected together.A couple of years ago I counted all ground rods and came up with 23. Before all of the metal was added and the "lightning rod" was the only metal extending about 20 ft. above the roof and we had an electrical storm my wife would complain that she could feel her hair trying to rise in response to the field coming from the cable which ran across the roof and at it's closest point was only 6-7 ft. from her head as the crow flies. But after all the additional metal was added in the form of antennas with grounds she no longer complained. I do not claim to understand what goes on around here at an elevation of about 102 ft. above the valley floor but I believe that we have been "fortunate" (or lucky if you prefer that word) and we have so much metal in the air that most "discharges" are not of the type that is accompanied by thunder! Two years ago we had a tree die that was no more than 30 ft. from the house. Since I have not always been able to accurately predict where trees will fall that I cut myself I hired a professional to take it down and he took one look at it, reached up and stripped off a piece of bark and commented, "See those lines? This tree was struck by lightning. That's what killed it!" But no lightning related damage to structure or equipment here for nearly 15 years! My only thought on the subject was that only a fool would fail to disconnect an antenna that rises above the house roof during an electrical storm. I freely admit that I have several ham radio VHF antennas (and a GPS antenna supplying the disciplined system for frequency reference) well below roof peak level (clear view to south for GPS, of course) that I do not disconnect from inexpensive radios maintained for the purpose. This is risk I accept. And I certainly have seen paths followed by lightning that are truly amazing! and horrendously damaging. Never forget that you only live once and you do have a perfect right to enjoy your hobby without fear. Regards, Lee A. Mushel K9WRU ----- Original Message ----- From: "quartz55" To: "Discussion of precise time and frequency measurement" Sent: Sunday, September 15, 2013 12:13 PM Subject: Re: [time-nuts] New NTBW50AA . I'm not thrilled having it above the beams, it's the highest metal thing in the area and most likely more prone to lightning than anything else excpet the trees and it will blow around a bit up there as well as rotating once in a while. I did have a strike here once, but it was down by the barn and was looking for the underground telephone cables, it blew apart a post and knocked off the boards, it was maybe 100 yards from the shack. It wouldn't be much of a problem to dig a tiny trench to the fence and I may try that after this precise survey is done, then do another and see if anything changes. I could hide it i n a bird box at the fence too. After all at this point I'm just playing. I'll eventually make up my mind. Also, I don't have an att
Re: [time-nuts] New NTBW50AA
All of this talk about antenna position has got me thinking about a better place for my antenna. I live in a rental townhouse and have no access to the roof and even if I did bringing a cable in from outside would be difficult, so am pretty much limited to an indoor antenna. My current antenna location is in a window on the second floor facing north west at a bearing of about 300 degrees, about 15 ft above the ground, as as many of you might guess it is not working that well. Looking around one possible other location would be on the top floor about 10 ft higher , with a straight out bearing if about 120 degrees on an exterior wall. The building is wood frame with drywall on the inside, fibreglass insulation and the exterior is covered with vinyl siding. Ideally I would like to stand the antenna in the corner of the room, but if it would make any difference there is a window in the room I could place the antenna in front of. This location will place it nearly as high as the surrounding roof tops and beyond that there is nothing as I an near the height of land in the area and a couple miles to the south is the Atlantic Ocean and its all water after that. The townhouse was pre-wired with RG-6 coax and I could use that to bring the signal to where my Nortel unit is. From what I gather RG-6 cable will work fine but I have a couple of concerns. 1. To get to where the receiver is I will need to go through the cable drop in the room where I plan to put the antenna, to the basement where all the drops are terminated, and then back up on another drop, so I will end up with 4 segments of cable and three couplings, will these couplings be and issue? The connectors involved would be F connectors. 2. At the antenna end it would be more convenient to use a piece of RG-59 cable between the antenna and the wall since it already has a TNC connector on the end that I need for the antenna, since they are both 75 ohm cables I don't think it would be an issue but I don't know for sure. One final question when we set a filter for elevation is that the elevation above ground or the elevation above the plane of the antenna? Paul. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Lee, if I can make a couple of comments, first, you can have large voltage differences among your 23 "ground" rods, depending on the ground terminus of the lightning strokes. Second, antennae and feed lines that do not attract lightning due to being "hidden" can still be subject to large induced voltages. I'd suggest all the ground rods and antenna bases be connected directly with large cable so they are all truly at the same ground potential... Don Lee Mushel > Lightning is certainly one of Old Mother Nature's principal weapons as > well > as being extremely unpredictable. My House/Shack is on the side of a > hill > with the Antenna Farm on top of the hill about 120 yds away with an > additional 30 ft. of elevation. There is a metal "lightning rod" > extending > high enough to provide a "cone of protection" for the house and is > grounded > directly. And there are five other metal antennas on that roof, two to > a > separate ground and three to still another which is close to the shack > "ground field" which is three additional ground rods. All ground rods > I > mention are the standard 8 ft. copper plated steel items. Each of five > antennas in the antenna field also have individual ground rods and I > guess > if you follow the cable shields you could say that they are all > connected > together.A couple of years ago I counted all ground rods and came up > with 23. Before all of the metal was added and the "lightning rod" was > the > only metal extending about 20 ft. above the roof and we had an > electrical > storm my wife would complain that she could feel her hair trying to rise > in > response to the field coming from the cable which ran across the roof > and at > it's closest point was only 6-7 ft. from her head as the crow flies. > But > after all the additional metal was added in the form of antennas with > grounds she no longer complained. > > I do not claim to understand what goes on around here at an elevation of > about 102 ft. above the valley floor but I believe that we have been > "fortunate" (or lucky if you prefer that word) and we have so much > metal in > the air that most "discharges" are not of the type that is accompanied > by > thunder! Two years ago we had a tree die that was no more than 30 ft. > from > the house. Since I have not always been able to accurately predict > where > trees will fall that I cut myself I hired a professional to take it down > and > he took one look at it, reached up and stripped off a piece of bark and > commented, "See those lines? This tree was struck by lightning. > That's > what killed it!" But no lightning related damage to structure or > equipment > here for nearly 15 years! > > My only thought on the subject was that only a fool would fail to > disconnect > an antenna that rises above the house roof during an electrical storm. > I > freely admit that I have several ham radio VHF antennas (and a GPS > antenna > supplying the disciplined system for frequency reference) well below > roof > peak level (clear view to south for GPS, of course) that I do not > disconnect from inexpensive radios maintained for the purpose. > > This is risk I accept. And I certainly have seen paths followed by > lightning that are truly amazing! and horrendously damaging. Never > forget that you only live once and you do have a perfect right to enjoy > your > hobby without fear. > > Regards, > > Lee A. Mushel K9WRU > > > - Original Message - > From: "quartz55" > To: "Discussion of precise time and frequency measurement" > > Sent: Sunday, September 15, 2013 12:13 PM > Subject: Re: [time-nuts] New NTBW50AA > > > . I'm not thrilled having it above the beams, it's the highest metal > thing > in the area and most likely more prone to lightning than anything else > excpet the trees and it will blow around a bit up there as well as > rotating > once in a while. I did have a strike here once, but it was down by the > barn > and was looking for the underground telephone cables, it blew apart a > post > and knocked off the boards, it was maybe 100 yards from the shack. It > wouldn't be much of a problem to dig a tiny trench to the fence and I > may > try that after this precise survey is done, then do another and see if > anything changes. I could hide it i >> n a bird box at the fence too. After all at this point I'm just >> playing. >> I'll eventually make up my mind. Also, I don't have an attic, so >> that's >> not an option. >> >
Re: [time-nuts] New NTBW50AA
Lightning is certainly one of Old Mother Nature's principal weapons as well as being extremely unpredictable. My House/Shack is on the side of a hill with the Antenna Farm on top of the hill about 120 yds away with an additional 30 ft. of elevation. There is a metal "lightning rod" extending high enough to provide a "cone of protection" for the house and is grounded directly. And there are five other metal antennas on that roof, two to a separate ground and three to still another which is close to the shack "ground field" which is three additional ground rods. All ground rods I mention are the standard 8 ft. copper plated steel items. Each of five antennas in the antenna field also have individual ground rods and I guess if you follow the cable shields you could say that they are all connected together.A couple of years ago I counted all ground rods and came up with 23. Before all of the metal was added and the "lightning rod" was the only metal extending about 20 ft. above the roof and we had an electrical storm my wife would complain that she could feel her hair trying to rise in response to the field coming from the cable which ran across the roof and at it's closest point was only 6-7 ft. from her head as the crow flies. But after all the additional metal was added in the form of antennas with grounds she no longer complained. I do not claim to understand what goes on around here at an elevation of about 102 ft. above the valley floor but I believe that we have been "fortunate" (or lucky if you prefer that word) and we have so much metal in the air that most "discharges" are not of the type that is accompanied by thunder! Two years ago we had a tree die that was no more than 30 ft. from the house. Since I have not always been able to accurately predict where trees will fall that I cut myself I hired a professional to take it down and he took one look at it, reached up and stripped off a piece of bark and commented, "See those lines? This tree was struck by lightning. That's what killed it!" But no lightning related damage to structure or equipment here for nearly 15 years! My only thought on the subject was that only a fool would fail to disconnect an antenna that rises above the house roof during an electrical storm. I freely admit that I have several ham radio VHF antennas (and a GPS antenna supplying the disciplined system for frequency reference) well below roof peak level (clear view to south for GPS, of course) that I do not disconnect from inexpensive radios maintained for the purpose. This is risk I accept. And I certainly have seen paths followed by lightning that are truly amazing! and horrendously damaging. Never forget that you only live once and you do have a perfect right to enjoy your hobby without fear. Regards, Lee A. Mushel K9WRU - Original Message - From: "quartz55" To: "Discussion of precise time and frequency measurement" Sent: Sunday, September 15, 2013 12:13 PM Subject: Re: [time-nuts] New NTBW50AA . I'm not thrilled having it above the beams, it's the highest metal thing in the area and most likely more prone to lightning than anything else excpet the trees and it will blow around a bit up there as well as rotating once in a while. I did have a strike here once, but it was down by the barn and was looking for the underground telephone cables, it blew apart a post and knocked off the boards, it was maybe 100 yards from the shack. It wouldn't be much of a problem to dig a tiny trench to the fence and I may try that after this precise survey is done, then do another and see if anything changes. I could hide it i n a bird box at the fence too. After all at this point I'm just playing. I'll eventually make up my mind. Also, I don't have an attic, so that's not an option. Dave N3DT ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Yes, I know it's not just the height of the trees, but the distance away and I'm really only getting 50-60' away at most and the hill is steep, it's about 20° in the worst spots. This is not your flat suburban lot, it's in the foothills of the Blue Ridge. The only flat spots are where we've made them. I'll have to go out and do a visual survey to see which one actually gives more free sky from say 20° up. Right now I'm tending towards the one towards the fence because it's not on the beam mast. But I'll let this survey finish. The WX is going to be good enough the rest of the week it'll be good outside working WX. It looks like the fence is really only 15' lower, if I put it at the arrow between those 2 gardens, I can keep the coax run at 100' and still have it up maybe 15'. http://i251.photobucket.com/albums/gg287/DogTi/time/land_zps9ee07b7a.jpg Dave It's not just the height of the trees, it's the horizontal distance from the antenna location to the trees, too -- the elevation angle above the antenna location (elevation = arctan (tree height/distance to trees) (in this case, "tree height" means height of the trees above the horizontal plane of the antenna, so it includes any difference in the ground height at the tree location, as well). At the end of the day, you want the most open sky you can get, particularly the southern hemisphere of sky, but the lowest elevations (say, under 20 degrees elevation) are not nearly as important as 20 through 90 degrees. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1432 / Virus Database: 3222/6167 - Release Date: 09/15/13 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Dave wrote: Well, I could try it down on the fence, but like I say when I get down there, I'm not sure the visibility above the trees is any better to the east and west because it's so much lower and the trees are all 80' high or more. It's not just the height of the trees, it's the horizontal distance from the antenna location to the trees, too -- the elevation angle above the antenna location (elevation = arctan (tree height/distance to trees) (in this case, "tree height" means height of the trees above the horizontal plane of the antenna, so it includes any difference in the ground height at the tree location, as well). At the end of the day, you want the most open sky you can get, particularly the southern hemisphere of sky, but the lowest elevations (say, under 20 degrees elevation) are not nearly as important as 20 through 90 degrees. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Well, I could try it down on the fence, but like I say when I get down there, I'm not sure the visibility above the trees is any better to the east and west because it's so much lower and the trees are all 80' high or more. Add another 30-40' for the drop and you can see what I mean. Like I say, it's a 200' drop from the house to the barn which is only 120 yards away. I'm not thrilled having it above the beams, it's the highest metal thing in the area and most likely more prone to lightning than anything else excpet the trees and it will blow around a bit up there as well as rotating once in a while. I did have a strike here once, but it was down by the barn and was looking for the underground telephone cables, it blew apart a post and knocked off the boards, it was maybe 100 yards from the shack. It wouldn't be much of a problem to dig a tiny trench to the fence and I may try that after this precise survey is done, then do another and see if anything changes. I could hide it i n a bird box at the fence too. After all at this point I'm just playing. I'll eventually make up my mind. Also, I don't have an attic, so that's not an option. Dave N3DT ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Dave wrote: The only other place I can put it would be about 100' to the south on the fence line, and unfortunately it's so steep, I've lost about 30' altitude there already. So the farther away I get from the house to a clearer location, the lower it gets; in about 200 yards it drops 200' The height of the antenna above average terrain doesn't mean a lot with satellite signals. What you need is a clear view of the sky above 10 or 15 degrees elevation for as much of the azimuth as you can arrange (and particularly the southern hemisphere of sky). So, for example, if you have a "high spot" on the property that is covered with trees that you can't get above with your GPS antenna, and a lower spot with a clear sky view, the lower spot is better for a GPS antenna. A hillside that slopes off to the south can be an excellent location. It sounds like somewhere to the south toward or at the fence line may be your best location. Use direct-burial coax, rent a ditch witch for the day, and you're set. Remember -- it is clear sky view you are after, NOT height. A bit of height above the nearby ground can help with multipath. Survey-grade choke-ring antennas are better about this by design. Some folks use a metal "ground plane" under the GPS antenna (it is not really operating as a ground plane, rather, it is simply shielding the antenna from low-incidence signals). If the antenna is at least 10 feet above the nearby ground and your elevation mask is set to 15 degrees or more, you shouldn't have multipath problems serious enough to degrade GPS timing (i.e., other errors will dominate). Note that the elevation mask can't reject the multipath itself -- it doesn't steer the antenna sensitivity -- but low satellites are the ones that suffer the most multipath unless you are in an "urban canyon" or have other strong L-band reflectors nearby, so by excluding low satellites you also exclude the multipath. Since low satellites also suffer the worst atmospheric variability, excluding them generally tightens up the timing solution also. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Well, that's what I'm doing right now. I just want to stabalize it a bit and make it so I can turn the beams. - Original Message - From: Bob Stewart To: Discussion of precise time and frequency measurement Sent: Sunday, September 15, 2013 10:40 AM Subject: Re: [time-nuts] New NTBW50AA It seems to me that you're fixing a problem that doesn't exist. Have you tried just putting it somewhere convenient and leaving it alone to see what happens? Bob - AE6RV ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
It seems to me that you're fixing a problem that doesn't exist. Have you tried just putting it somewhere convenient and leaving it alone to see what happens? Bob - AE6RV > > From: quartz55 >To: Discussion of precise time and frequency measurement >Sent: Sunday, September 15, 2013 9:32 AM >Subject: Re: [time-nuts] New NTBW50AA > > >The only other place I can put it would be about 100' to the south on the >fence line, and unfortunately it's so steep, I've lost about 30' altitude >there already. So the farther away I get from the house to a clearer >location, the lower it gets; in about 200 yards it drops 200' to Buck Run. And >I think that's a loosing proposition. > >I'll see if I can't get someone to help and install it on the rotating mast in >line with the pipe and install the lower outrigger which will minimize the >leveraged wind displacement. Anyone nearby? I can trade some UHF/VHF >Spectras for help with the work. I've got a few other things like mobile >antennas that I can loose. I may call up the local ARC. I'm just real >fearful of standing on that chimney any more, I don't mind walking around on >the 4/12 part of the roof. > >Almost 1/2 way through the SP command. > >Dave > - Original Message - > From: Bob Camp > To: Discussion of precise time and frequency measurement > Sent: Saturday, September 14, 2013 1:40 PM > Subject: Re: [time-nuts] New NTBW50AA > > > Hi > > As long as the wind does not blow the tower around, that's probably your >best location. > > Bob >___ >time-nuts mailing list -- time-nuts@febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. > > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
The only other place I can put it would be about 100' to the south on the fence line, and unfortunately it's so steep, I've lost about 30' altitude there already. So the farther away I get from the house to a clearer location, the lower it gets; in about 200 yards it drops 200' to Buck Run. And I think that's a loosing proposition. I'll see if I can't get someone to help and install it on the rotating mast in line with the pipe and install the lower outrigger which will minimize the leveraged wind displacement. Anyone nearby? I can trade some UHF/VHF Spectras for help with the work. I've got a few other things like mobile antennas that I can loose. I may call up the local ARC. I'm just real fearful of standing on that chimney any more, I don't mind walking around on the 4/12 part of the roof. Almost 1/2 way through the SP command. Dave - Original Message - From: Bob Camp To: Discussion of precise time and frequency measurement Sent: Saturday, September 14, 2013 1:40 PM Subject: Re: [time-nuts] New NTBW50AA Hi As long as the wind does not blow the tower around, that's probably your best location. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Do you have any idea how much the antenna will move in a strong wind? It really needs to be in a secure rigid position for optimum timing performance. Sorry if this has been covered before but just picked up the thread. Rob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of quartz55 Sent: 14 September 2013 18:26 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] New NTBW50AA Here's a better view of the antenna looking due south. http://i251.photobucket.com/albums/gg287/DogTi/abovebeamssouth_zpsd8fb78ca.j pg Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi If you mostly keep the beams pointed into the wind, I'd do that before you do the next survey. Bob On Sep 14, 2013, at 2:59 PM, "quartz55" wrote: > If it's on the top of the antenna mast, it should only rotate around the > mast, which may be 4" at most. I can stabalize the mast a bit with a > outrigger at the bottom which I've been meaning to do for years. The pipe > from the chimney is 1" thick wall, so there isn't much wind effect there, I > forget what the mast is, whatever fit in the Alliance rotator. It survived > Sandy which brought down a huge oak on the roof and whacked the very end > director of the 2M beam and bent one side down. If you're interested > http://s251.photobucket.com/user/DogTi/library/Tree?sort=4&page=1 > > Thanks, yeah I always get messed up with decimals and powers of 10, > especially when they flip from + to -, unless I work with them all the time, > plus I've got old age brain rot. It ain't what it used to be. > > I'm doing a precision survey now. > > Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
If it's on the top of the antenna mast, it should only rotate around the mast, which may be 4" at most. I can stabalize the mast a bit with a outrigger at the bottom which I've been meaning to do for years. The pipe from the chimney is 1" thick wall, so there isn't much wind effect there, I forget what the mast is, whatever fit in the Alliance rotator. It survived Sandy which brought down a huge oak on the roof and whacked the very end director of the 2M beam and bent one side down. If you're interested http://s251.photobucket.com/user/DogTi/library/Tree?sort=4&page=1 Thanks, yeah I always get messed up with decimals and powers of 10, especially when they flip from + to -, unless I work with them all the time, plus I've got old age brain rot. It ain't what it used to be. I'm doing a precision survey now. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
> I get a spread of around 300ppt, that means I'm always within > 300x10^-9 Hz of 10MHz or .0003Hz at 1GHz? Note "300 ppt" is a "fractional frequency", unit-less value, so at 10 MHz, 300e-12 * 1e7 Hz = 0.003 Hz at 1 GHz, 300e-12 * 1e9 Hz = 0.3 Hz > I suppose the ppt spread is pretty much a function of how stable the osc is > once > other factors like temp, antenna position, sat acquisition, etc, are > optimized? Yes and no; it's a complicated subject. For now, just two points: A measure of frequency implies some measurement duration. A given TBolt may be off by more than 1e-11 in frequency over seconds or minutes even though if you measure over a day it is accurate to less than 1e-13. This is one problem with interpreting the "OSC" value. A second problem is that a TBolt can't really know its own accuracy; that requires an external frequency reference, so take the PPS and OSC with a grain of salt. However, in general, the TBolt will steer its 10 MHz oscillator so as to minimize the PPS and OSC values. As such they can be used as a rough idea of how well the unit is performing. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi As long as the wind does not blow the tower around, that's probably your best location. Bob On Sep 14, 2013, at 1:26 PM, "quartz55" wrote: > Here's a better view of the antenna looking due south. > http://i251.photobucket.com/albums/gg287/DogTi/abovebeamssouth_zpsd8fb78ca.jpg > > Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi On Sep 14, 2013, at 12:45 PM, "quartz55" wrote: > Today I moved the antenna to above the beams. This is temporary because it's > in the way of the beams turning. I guess I need to get someone out here to > help me install it on top of the beam mast. I don't feel confident to do it > myself anymore. I suppose it's not going to hurt anything if once in a while > the antenna gets rotated? Just not while I'm doing something with the > Nortel. It's pretty much in the clear and as high as I can get it. It sees > clear sky especially to the south except for one tree and the antenna is > probably within 10' of that tree's height. There are still trees to the east > that I just can't do much about. The ones to the west are about 100' away > and the antenna shouldn't see them much. > As long as the GPS antenna does not rotate that should be a good location. If it rotates, you will get a few inches of displacement which is less than ideal. The larger issue will be how the antenna handles lightning and the near field transmit power from the beams. > http://i251.photobucket.com/albums/gg287/DogTi/time/abovebeams_zpsbf8474c1.jpg > > So the Osc ppt is the offset from what the Nortel thinks is exactly 10MHz as > I read it on page 117 of the ThunderBolt instructions (thanks Tom). How do I > tell how accurate the Nortel thinks exactly 10MHz is, or can I assume it's > right? If right is the case, then if I get a spread of around 300ppt, that > means I'm always within 300x10^-9 Hz of 10MHz or .0003Hz at 1GHz? PPT = parts per trillion that's one in 1,000,000,000,000 (12 zeros). One Hz at 10 MHz is 0.1 PPM. PPM is 1 in 1,000,000 (six zeros). PPB is nine zeros, or one Hz at 1 GHz. It's also one nanosecond per second. 300 ppt would be 0.3 Hz at one GHz. (yes, you can find a *lot*) of posts to the list where I've slipped a decimal on that stuff). > Or is my thinking off base and did I miss a decimal somewhere? I suppose > the ppt spread is pretty much a function of how stable the osc is once other > factors like temp, antenna position, sat acquisition, etc, are optimized? Also include the errors in the GPS signal: 1) Uncorrected ionospheric errors 2) GPS clock errors 3) GPS almanac errors 4) Antenna location errors (including interesting trivia like tides) 5) Multi path signal errors 6) Temperature induced errors (or not) on the antenna 7) Drift / phase errors in the GPS receiver (there's lots of doppler on the signals). 8) Just plain dumb decisions by the firmware Since most of the GPS errors are going to "track out" they will not show up on the display. They will indeed shift your output frequency. > That's what I infer from what Skip Withrow from RDR told me about the > oscillators. He told me they can vary by a factor of 10. The temperature stability of those OCXO's likely is within about 2:1. Aging wise they are like any OCXO, the longer they are kept power on, the less they will drift. Bob > > Dave > N3DT > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Here's a better view of the antenna looking due south. http://i251.photobucket.com/albums/gg287/DogTi/abovebeamssouth_zpsd8fb78ca.jpg Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Today I moved the antenna to above the beams. This is temporary because it's in the way of the beams turning. I guess I need to get someone out here to help me install it on top of the beam mast. I don't feel confident to do it myself anymore. I suppose it's not going to hurt anything if once in a while the antenna gets rotated? Just not while I'm doing something with the Nortel. It's pretty much in the clear and as high as I can get it. It sees clear sky especially to the south except for one tree and the antenna is probably within 10' of that tree's height. There are still trees to the east that I just can't do much about. The ones to the west are about 100' away and the antenna shouldn't see them much. http://i251.photobucket.com/albums/gg287/DogTi/time/abovebeams_zpsbf8474c1.jpg So the Osc ppt is the offset from what the Nortel thinks is exactly 10MHz as I read it on page 117 of the ThunderBolt instructions (thanks Tom). How do I tell how accurate the Nortel thinks exactly 10MHz is, or can I assume it's right? If right is the case, then if I get a spread of around 300ppt, that means I'm always within 300x10^-9 Hz of 10MHz or .0003Hz at 1GHz? Or is my thinking off base and did I miss a decimal somewhere? I suppose the ppt spread is pretty much a function of how stable the osc is once other factors like temp, antenna position, sat acquisition, etc, are optimized? That's what I infer from what Skip Withrow from RDR told me about the oscillators. He told me they can vary by a factor of 10. Dave N3DT ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Yeah, that's what I'm worried about, I've got enough lifetime supplies of junk around here now. Oddly enough some were replacements for other "lifetime" supplies that got used up…. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi Unless you have it shipped in, that's pretty much the situation everywhere. I have several lifetime supply spools of this and that. Some of them I bought new. Others I picked up at garage sales, still with a lifetime supply of cable on the spool. Oddly enough some were replacements for other "lifetime" supplies that got used up…. Bob On Sep 12, 2013, at 9:50 PM, quartz55 wrote: > Well, I was in HD tonight and 100' is $25. Otherwise they had a roll of 500' > for around $50. Nothing in between. You have to realize nothing out here in > the boonies comes easy. I only need maybe 150' and actually the 3 pieces of > 50' I have are not that old. We'll see what happens. Right now it seems to > be working a little better with the antenna on the kitchen vent. I don't > know what I'd do with 500'. > > Dave > - Original Message - > From: Bob Camp > To: Discussion of precise time and frequency measurement > Sent: Thursday, September 12, 2013 5:59 PM > Subject: Re: [time-nuts] New NTBW50AA > > > Hi > > Looks like RG-6 Quad Shield is about $50 for a 500' spool at the local big > box stores. > > Bob > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
The LH OSCdisplay is measuring 'parts per trillion/div' of what? Sorry for the basic question, but I have not found it. At least I figured out it was trillion, not thousand. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Well, I was in HD tonight and 100' is $25. Otherwise they had a roll of 500' for around $50. Nothing in between. You have to realize nothing out here in the boonies comes easy. I only need maybe 150' and actually the 3 pieces of 50' I have are not that old. We'll see what happens. Right now it seems to be working a little better with the antenna on the kitchen vent. I don't know what I'd do with 500'. Dave - Original Message - From: Bob Camp To: Discussion of precise time and frequency measurement Sent: Thursday, September 12, 2013 5:59 PM Subject: Re: [time-nuts] New NTBW50AA Hi Looks like RG-6 Quad Shield is about $50 for a 500' spool at the local big box stores. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi Looks like RG-6 Quad Shield is about $50 for a 500' spool at the local big box stores. Bob On Sep 12, 2013, at 10:10 AM, quartz55 wrote: > OK, I cleaned up the connectors and it's working again at the new location. > As soon as I get into town, I'll get some new coax. > > Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
OK, I cleaned up the connectors and it's working again at the new location. As soon as I get into town, I'll get some new coax. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Will too long a cable run or too many connectors (2) result in "antenna open"? When I added the last 50' of cable that's what I got. I measure 5V at the end of the cable run though. Maybe some de-ox in the connectors will help? I can also go get a single long run instead of piecing it together. I'll try a few things before heading into town. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi As you do these surveys, write down the results. You probably will do several surveys on each antenna location before you are done. Looking at the variation between the results will give you an idea of what's going on. Bob On Sep 11, 2013, at 9:48 PM, quartz55 wrote: > I ordered a couple of the temp chips, but it's going to be low on the list of > priorities. > > Tomorrow I'll add another 30' of cable and mount the antenna on the kitchen > vent which is right on the south end of the house above the deck, lower but > southeast from the beams by 25' or so. I think that's about as good as I can > do unless I put up a tower to get above everything and that's not going to > happen. > > I broke a chip inductor in the TS-2000 trying to install the XRef today, so I > have to wait a few days until I get some new parts in. I can do a 24 hour > precision survey in the meantime. I had to get the headband magnifier out to > work on this thing, the board is only 1.25" x 0 .4". The chip inductor I > broke is only about a 2mm cube. I got it off the 2000 board OK, I broke the > track off the chip trying to solder a wire on one end. Next time I'm going > to solder it and then glue it. > http://i251.photobucket.com/albums/gg287/DogTi/time/XRef_zps74f23696.jpg > > I've got about 2 acres of grass to cut and need to put the sickle bar on the > JD and go out and kill a few stink bugs in this heat. > > Dave > N3DT > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
I ordered a couple of the temp chips, but it's going to be low on the list of priorities. Tomorrow I'll add another 30' of cable and mount the antenna on the kitchen vent which is right on the south end of the house above the deck, lower but southeast from the beams by 25' or so. I think that's about as good as I can do unless I put up a tower to get above everything and that's not going to happen. I broke a chip inductor in the TS-2000 trying to install the XRef today, so I have to wait a few days until I get some new parts in. I can do a 24 hour precision survey in the meantime. I had to get the headband magnifier out to work on this thing, the board is only 1.25" x 0 .4". The chip inductor I broke is only about a 2mm cube. I got it off the 2000 board OK, I broke the track off the chip trying to solder a wire on one end. Next time I'm going to solder it and then glue it. http://i251.photobucket.com/albums/gg287/DogTi/time/XRef_zps74f23696.jpg I've got about 2 acres of grass to cut and need to put the sickle bar on the JD and go out and kill a few stink bugs in this heat. Dave N3DT ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi Ideally you would like the position error to be under 10" for the device to work at it's best. That's probably going to equate to a couple of inches of error in X, Y, and Z. Since GPS has cyclical errors, you need an average over a few days to get to that level. Bob On Sep 11, 2013, at 1:49 PM, quartz55 wrote: > The lat lon did change when I did the survey. On google, the lat lon is real > close, a foot or so for the before position and after also. It certainly > doesn't march around the neighborhood looking, the last survey must have only > taken a few minutes. As far as antenna position, I guess maybe I can put it > over on the hughes dish, but it's closer to the trees there. How far away > from those beams do I need to get, so they're not in the el mask? Maybe I > could put it on one of the roof vents but the coax will then drag across the > shingles. I'll have to think about this. On the deck is good, but the wifey > wouldn't go for that and it would be lots lower. Maybe if I paint it flat > black she won't see it. > > You can see where google reports it here and the arrow is more where it is, > so maybe it's 4-5' off. > http://i251.photobucket.com/albums/gg287/DogTi/time/roof_zps5eccff6a.jpg > > Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
The lat lon did change when I did the survey. On google, the lat lon is real close, a foot or so for the before position and after also. It certainly doesn't march around the neighborhood looking, the last survey must have only taken a few minutes. As far as antenna position, I guess maybe I can put it over on the hughes dish, but it's closer to the trees there. How far away from those beams do I need to get, so they're not in the el mask? Maybe I could put it on one of the roof vents but the coax will then drag across the shingles. I'll have to think about this. On the deck is good, but the wifey wouldn't go for that and it would be lots lower. Maybe if I paint it flat black she won't see it. You can see where google reports it here and the arrow is more where it is, so maybe it's 4-5' off. http://i251.photobucket.com/albums/gg287/DogTi/time/roof_zps5eccff6a.jpg Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Oh, the XRef from VK3HZ is at the PO, I'm going to go get it. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
I am tempted to use the monty python exhortation "Start again" If I am reading your screen shots correctly the 01:51:57 UTC shot is before the antenna move and the 14:02:03 one after the move. HOWEVER, both shots show the same saved position. That is certainly not going to be optimal. You should let it survey again. Mike Le 11 sept. 2013 à 16:17, quartz55 a écrit : > Thanks Charles, > > I'm not certain myself it it's the temp chip or the way LH handles the > information. It doesn't matter like you say, there's no use doing any > measurements with the unit unlocked. > > Otherwise here is a trace while I moved the antenna. Any comments on how it > reacted in holdover? > http://i251.photobucket.com/albums/gg287/DogTi/time/holdover_zps35d7e81b.jpg > And here is where the antenna is now, this is looking straight north, so the > sky behind me is nearly clear to the horizon and straight up isn't bad either. > http://i251.photobucket.com/albums/gg287/DogTi/time/gpsant_zps2963365a.jpg > > Dave > N3DT > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Dave With your GPS Antenna sitting underneath all those multipath reflectors (the other antenna's above it), That is far from optimal from a time-nut standpoint if you are trying to get the best performance possible. Should strive for no metal or reflective surfaces above the GPS antenna in any direction. ws * - Original Message - From: "quartz55" To: "Discussion of precise time and frequency measurement" Subject: Re: [time-nuts] New NTBW50AA Thanks Charles, I'm not certain myself it it's the temp chip or the way LH handles the information. It doesn't matter like you say, there's no use doing any measurements with the unit unlocked. Otherwise here is a trace while I moved the antenna. Any comments on how it reacted in holdover? http://i251.photobucket.com/albums/gg287/DogTi/time/holdover_zps35d7e81b.jpg And here is where the antenna is now, this is looking straight north, so the sky behind me is nearly clear to the horizon and straight up isn't bad either. http://i251.photobucket.com/albums/gg287/DogTi/time/gpsant_zps2963365a.jpg Dave N3DT ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
I can testify to Warren's comments. I've got an Adafruit Breakout Board that I hook up to my computer from time to time, and it marches all around the neighborhood on the map looking for my house. =) Eventually my timing antenna will go up in the attic, just under the peak. Bob - AE6RV > > From: WarrenS >To: Discussion of precise time and frequency measurement >Sent: Wednesday, September 11, 2013 12:10 PM >Subject: Re: [time-nuts] New NTBW50AA > > > >Dave > >With your GPS Antenna sitting underneath all those multipath reflectors (the >other antenna's above it), >That is far from optimal from a time-nut standpoint if you are trying to get >the best performance possible. >Should strive for no metal or reflective surfaces above the GPS antenna in any >direction. > >ws > >* > >- Original Message - From: "quartz55" >To: "Discussion of precise time and frequency measurement" >Subject: Re: [time-nuts] New NTBW50AA > > >Thanks Charles, > >I'm not certain myself it it's the temp chip or the way LH handles the >information. It doesn't matter like you say, there's no use doing any >measurements with the unit unlocked. > >Otherwise here is a trace while I moved the antenna. Any comments on how it >reacted in holdover? >http://i251.photobucket.com/albums/gg287/DogTi/time/holdover_zps35d7e81b.jpg >And here is where the antenna is now, this is looking straight north, so the >sky behind me is nearly clear to the horizon and straight up isn't bad either. >http://i251.photobucket.com/albums/gg287/DogTi/time/gpsant_zps2963365a.jpg > >Dave >N3DT > >___ >time-nuts mailing list -- time-nuts@febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. > > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Well, this is interesting, after moving the antenna and doing a new survey, the OSC ppt has gone down quite a bit. Looky here, you can see the before, the survey and after ppt http://i251.photobucket.com/albums/gg287/DogTi/time/survey11sep_zpsff5a5b58.jpg Would a precision survey do any better? Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
I heard from RDR electroncis this morning and he says, like Arthur says, the older chips work better with LH. I'm just not going to worry about it for now. He was willing to take it back, but I'm not going to do that. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Thanks Charles, I'm not certain myself it it's the temp chip or the way LH handles the information. It doesn't matter like you say, there's no use doing any measurements with the unit unlocked. Otherwise here is a trace while I moved the antenna. Any comments on how it reacted in holdover? http://i251.photobucket.com/albums/gg287/DogTi/time/holdover_zps35d7e81b.jpg And here is where the antenna is now, this is looking straight north, so the sky behind me is nearly clear to the horizon and straight up isn't bad either. http://i251.photobucket.com/albums/gg287/DogTi/time/gpsant_zps2963365a.jpg Dave N3DT ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Dave wrote: I set the temp scale to 250m°C/div last night and it remained steady for quit a while, but then it started the jumping again. It seems to jump on 1° increments, like from 37.750 to 38.749 in less than 1 minute, but there are step variations during the 1° movements. I do not know whether LH just displays every "n-th" sample to produce long-time-scale plots, or whether it averages "n" samples to get the displayed value. If it averages, each pixel would include data from more than one sample, which would produce intermediate values that the GPSDO did not actually report. You may want to set the time scale so you can see each one-second sample (I think one minute per division will do this). At that scale, you may find that all of the samples are in one degree increments. In other words, the appearance of intermediate values may be an artifact of display averaging -- the actual data from the GPSDO may be strictly in 1v increments. Mark could say for sure. So what you're saying is it won't affect the freq stab or adev? We (the time-nuts community) do not have hard data about how the temperature data is used in the Trimble GPSDOs, but it appears that it is not used during locked operation except to "teach" the unit about the OCXO's temperature coefficient. What it has "learned" is applied during holdover in an attempt to improve holdover stability. I doubt many time nuts would make critical measurements while their GPSDO was unlocked, so there is probably no practical difference as far as we are concerned. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
I set the temp scale to 250m°C/div last night and it remained steady for quit a while, but then it started the jumping again. It seems to jump on 1° increments, like from 37.750 to 38.749 in less than 1 minute, but there are step variations during the 1° movements. So what you're saying is it won't affect the freq stab or adev? And yes the room temp is quite stable, it's about 1/2 underground to 3 sides and the A/C runs most of the time this time of year. I guess it's not worth hounding the seller about it if the others he has are just like it. It's just a matter of if I want to replace the chip. Looks like they're up to DS1620S by now. I'm not going to worry about it for now. But I am going to move the antenna over to where it sees the sky without the trees this morning before it gets to 90°. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi Ok, you have an unusually well controlled environment in your shack. The pops are the temperature just barely making it to a 1 C excursion. Think of your temperature as a sort of sine wave. The pops are the peaks of the sine wave. Bob On Sep 10, 2013, at 10:02 PM, quartz55 wrote: > Well, here's a shot with me putting a fan under the bottom of the unit and > you can see the temp immediately start to drop from 39.7 down to 29.7 and > then I take the fan away and it goes back up to 37.7 and now I've let the > bottom breathe which I had blocked off by letting it sit on the bottom. I > would say the temp sensor is working, but still why those jumps? I'll let it > run with the bottom/top open and see what happens then. But it was doing > these jumps with the cover off before as I remember. Wonder if I should have > a bit of forced ventilation in this thing? > http://s251.photobucket.com/user/DogTi/media/time/temptest_zps4eda29a5.jpg.html?sort=3&o=0 > > Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Well, here's a shot with me putting a fan under the bottom of the unit and you can see the temp immediately start to drop from 39.7 down to 29.7 and then I take the fan away and it goes back up to 37.7 and now I've let the bottom breathe which I had blocked off by letting it sit on the bottom. I would say the temp sensor is working, but still why those jumps? I'll let it run with the bottom/top open and see what happens then. But it was doing these jumps with the cover off before as I remember. Wonder if I should have a bit of forced ventilation in this thing? http://s251.photobucket.com/user/DogTi/media/time/temptest_zps4eda29a5.jpg.html?sort=3&o=0 Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi It should be measuring ambient temperature. The GPSDO probably uses it as part of the holdover process. A good blast of room temperature air (heat gun without the heater on) *should* drop the sensor 5 to 10 degrees. Bob On Sep 10, 2013, at 8:43 PM, quartz55 wrote: > Be a lot easier just to blow the heat gun on it. What is this sensor > measuring, ambient temperature in the room of something on the board, like > the OCXO or what? It only seems to vary from about 37.7 to 41.7 and it > always seems to change in 1° increments. Is it going to affect how the GPSDO > works? > > Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Be a lot easier just to blow the heat gun on it. What is this sensor measuring, ambient temperature in the room of something on the board, like the OCXO or what? It only seems to vary from about 37.7 to 41.7 and it always seems to change in 1° increments. Is it going to affect how the GPSDO works? Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi
The time constant / oscillator tuning data does not save to eeprom on the
NTBW50 and similar units. Works fine on a TBolt….
Bob
On Sep 10, 2013, at 12:07 PM, Charles Steinmetz wrote:
> Dave wrote:
>
>> Also how do I set the time constant, I can't find it anywhere except if I do
>> the &a command but it resets back to 100s with a new start.
>
> Does the TC not get saved when you "save to EPROM"? It does with a
> Thunderbolt.
>
> Also, a number of people have expressed confusion with making LH display
> parameters "stick" from one session to the next. Learn the power of the
> "slash" commands! Many LH parameters can be pre-set at launch using slash
> ("/") commands passed to LH in the launch command. (LH can also read a
> configuration or ".ini" file for these parameters, but I have not tried this.)
>
> If you look at the index you get when you hit , one of the choices
> will be to view the slash commands. (You can also use the slash commands
> while LH is running, but they will not be saved. For that, you need to pass
> them to LH at each launch, either in the launch command or in a configuration
> file.)
>
> Best regards,
>
> Charles
>
>
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi Simple way to check it: Let the temperature in the room move over a 10 C range (open a window …). If the temperature trace does not move the chip isn't doing what it should. Bob On Sep 10, 2013, at 5:31 PM, quartz55 wrote: > Arthur, > > Can you tell me where and what the chip is and if there's any way to test it > on the board? I've got a 30 day $ back deal on this thing. > > Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi I have quite a few of these and they all produce temperature plots that look like proper TBolts. I also have TBolts that don't read the sensor in high resolution mode. I have a couple TBolts with broken temperature sensor chips. Assuming the room temperature is varying several degrees C up and down over the time shown, those plots most closely resemble a TBolt with a blown chip. Bob On Sep 10, 2013, at 3:38 PM, Arthur Dent wrote: >> Mark Sims holrum at hotmail.com >> Tue Sep 10 09:03:24 EDT 2013 >> >> Again, THE TEMPERATURE SENSOR IS NOT BROKEN!! The firmware in >> some of these units (those from NTPX modules) does NOT read the temperature >> sensor in high-res mode. > > I have sold over 200 T-bolts and had to replace about 30 of their thermometer > chips, > most because of the revision problem causing the 'stepped' temp plot, but > some > because of chip failure. If this were the typical low res problem the yellow > trace > would show the characteristic uniform staircase steps, not the random jumps > to > some common value that it never exceeds. If you look closely at the plot > you'll > see many very small changes that are far smaller than any of the steps would > be. > Also there are major portions of the trace where it is absolutely flat and I > doubt that > this is really happening. I'll stick with broken but maybe someone else with > another > NTBW50AA can run LH and show what their graph looks like. > > -Arthur > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Arthur, Can you tell me where and what the chip is and if there's any way to test it on the board? I've got a 30 day $ back deal on this thing. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
No I didn't do the e command. I don't want to write to the prom any more than I have to at this point while I'm playing with it. Yes, I see the time constant under the & command now, &t. I knew about the launch / commands, I just don't know what I want to use at this point, if I want to change anything or not. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Re the time constant, the only way of changing it I'm aware of is with the & command, have you tried "e" to save the current configuration? Regards Nigel GM8PZR In a message dated 10/09/2013 16:19:00 GMT Daylight Time, quart...@hughes.net writes: Mine's reporting 6 places too. I get these 'big' variations, but it only moves from 38.7 to 41.7 C. Is this pretty normal? Also how do I set the time constant, I can't find it anywhere except if I do the &a command but it resets back to 100s with a new start. Dave - Original Message - From: gandal...@aol.com To: time-nuts@febo.com Sent: Tuesday, September 10, 2013 10:02 AM Subject: Re: [time-nuts] New NTBW50AA Hi Mark I'm currently monitoring two of these units with LH running on two separate PCs and temperature for each is being reported to six decimal places, does this mean LH is in some way interpolating the higher resolution readings? Regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Dave wrote:
Also how do I set the time constant, I can't find it anywhere except
if I do the &a command but it resets back to 100s with a new start.
Does the TC not get saved when you "save to EPROM"? It does with a
Thunderbolt.
Also, a number of people have expressed confusion with making LH
display parameters "stick" from one session to the next. Learn the
power of the "slash" commands! Many LH parameters can be pre-set at
launch using slash ("/") commands passed to LH in the launch
command. (LH can also read a configuration or ".ini" file for these
parameters, but I have not tried this.)
If you look at the index you get when you hit , one of the
choices will be to view the slash commands. (You can also use the
slash commands while LH is running, but they will not be saved. For
that, you need to pass them to LH at each launch, either in the
launch command or in a configuration file.)
Best regards,
Charles
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi, I have a a small correction to my message, I was talking from memory. After checking with the real thing I found that 2 commands are needed: One for turning the yellow LED (Comm fault) off and other for turning the Green one (Normal) on. Ignacio EB4APL On 10/09/2013 13:47, EB4APL wrote: Dave, I have a cousin of your GPSDO, a NTGS50AA whose main differences are that in this unit the DB-9 connector and the LEDs are in a separate board connected by a flat cable, and that this unit is meant for -48 volts systems only. The yellow light indicates that it is not in communication with the mainframe for about 30 seconds so it is labeled comm error. There are two ways to turn it green: - Emulate a small subset of the mainframe protocol with a microcontroller and communicate with the board through the 110 pin connector in the back. Nothing useful and quite complicated. - Ask Mark Sims to include in LH a function to periodically send a command to turn the lamp green. I verified with the Trimble-Nortel installation tool (GPS_Monitor) that if you tick the box for commanding the LED to green, it stays green until the program quits, so it is periodically resetting the comm timeout counter. With this function the LED would be green as long LH is in communication with the box and would turn yellow if the program quits or the communication is lost, like when the box is installed in a cell tower. Just an idea, Ignacio EB4APL On 10/09/2013 4:31, quartz55 wrote: OK, did a bit more reading. I already understand the difference between accuracy and stability however. I thought ADEV was some sort of measurement of accuracy, but I understand now it is a measure of stability over time. I'm supposing now that I can assume that the best frequency accuracy I can imagine is what is specked in the book for the unit, <.8x10^-10. That should be good enough for me. Although most seem to say the GPSDO units are good for .1Hz at 10GHz which I think would be 10^-13 no? Yeah, I've read through the h...cpp and a lot of it is greek to me, I'm no programmer, but I can pull a bunch of stuff out of it. But it doesn't explain the acronyms or the meanings of them. I've lowered the el mask to 20 and I get plenty of sats now. When it was at 43, lots of times it was down to 2, now it's generally up to 6. I'll see how it does, especially if it rains, and yes the trees really cover the antenna. I am getting 30-40 or more dBc however which is what I had when it was more in the clear. I can move it to the west about 30' on the chimney where my UHF/VHF beams are and it's a lot more open straight up and especially to the south. The position where it is now is just real convenient and it's only maybe 25' from the unit. Plus I didn't have to get up on that part of the roof that's 7 in 12. Yes, I notice the gis for our county seems to have a slightly different co-ordinate system, they don't line up with google or the GPS which seem to agree as far as I can zoom in on our location. I'd say the GPS and google are within a foot or 2. I guess I can just turn off the temp chart if it's not going to report right and stop looking/worrying about it. As long as the green lock light is on. I wonder if I could trick the Nortel unit into thinking it's seeing the CM though, so the top green light would come on instead of the yellow one. But that doesn't matter. Thanks for all your help, I'll hang around for a while. Dave N3DT ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Mine's reporting 6 places too. I get these 'big' variations, but it only moves from 38.7 to 41.7 C. Is this pretty normal? Also how do I set the time constant, I can't find it anywhere except if I do the &a command but it resets back to 100s with a new start. Dave - Original Message - From: gandal...@aol.com To: time-nuts@febo.com Sent: Tuesday, September 10, 2013 10:02 AM Subject: Re: [time-nuts] New NTBW50AA Hi Mark I'm currently monitoring two of these units with LH running on two separate PCs and temperature for each is being reported to six decimal places, does this mean LH is in some way interpolating the higher resolution readings? Regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi Mark I'm currently monitoring two of these units with LH running on two separate PCs and temperature for each is being reported to six decimal places, does this mean LH is in some way interpolating the higher resolution readings? Regards Nigel GM8PZR In a message dated 10/09/2013 14:04:05 GMT Daylight Time, hol...@hotmail.com writes: Again, THE TEMPERATURE SENSOR IS NOT BROKEN!! The firmware in some of these units (those from NTPX modules) does NOT read the temperature sensor in high-res mode. -- Your temperature plots look like mine. I suspect the other unit has a broken temperature detection chip. I've seen that happen on TBolts. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
OK, I believe you Mark. I do wonder why the DAC and OSC traces on Authur's unit are much smaller than mine though. Seem to be in the same units. I'll check it in a month or so. I was thinking last night that it wouldn't be much to move the antenna over to where it's open straight up and to the south too. It's blocked a bit to the east and west though, not much I can do about that unless I get it up about 80'. Wow, 200' huh. If that's the case, I can move that antenna around over by the property line which is only about 100' from the room. Trouble is it's completely in the trees there. Maybe I should just pay a surveyor and be done with it. I've got a couple other property lines I need marked too and they're more like a half mile away. Dave - Original Message - From: Mark Sims To: time-nuts@febo.com Sent: Tuesday, September 10, 2013 9:03 AM Subject: [time-nuts] New NTBW50AA Again, THE TEMPERATURE SENSOR IS NOT BROKEN!! The firmware in some of these units (those from NTPX modules) does NOT read the temperature sensor in high-res mode. -- Your temperature plots look like mine. I suspect the other unit has a broken temperature detection chip. I've seen that happen on TBolts. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Dave, I have a cousin of your GPSDO, a NTGS50AA whose main differences are that in this unit the DB-9 connector and the LEDs are in a separate board connected by a flat cable, and that this unit is meant for -48 volts systems only. The yellow light indicates that it is not in communication with the mainframe for about 30 seconds so it is labeled comm error. There are two ways to turn it green: - Emulate a small subset of the mainframe protocol with a microcontroller and communicate with the board through the 110 pin connector in the back. Nothing useful and quite complicated. - Ask Mark Sims to include in LH a function to periodically send a command to turn the lamp green. I verified with the Trimble-Nortel installation tool (GPS_Monitor) that if you tick the box for commanding the LED to green, it stays green until the program quits, so it is periodically resetting the comm timeout counter. With this function the LED would be green as long LH is in communication with the box and would turn yellow if the program quits or the communication is lost, like when the box is installed in a cell tower. Just an idea, Ignacio EB4APL On 10/09/2013 4:31, quartz55 wrote: OK, did a bit more reading. I already understand the difference between accuracy and stability however. I thought ADEV was some sort of measurement of accuracy, but I understand now it is a measure of stability over time. I'm supposing now that I can assume that the best frequency accuracy I can imagine is what is specked in the book for the unit, <.8x10^-10. That should be good enough for me. Although most seem to say the GPSDO units are good for .1Hz at 10GHz which I think would be 10^-13 no? Yeah, I've read through the h...cpp and a lot of it is greek to me, I'm no programmer, but I can pull a bunch of stuff out of it. But it doesn't explain the acronyms or the meanings of them. I've lowered the el mask to 20 and I get plenty of sats now. When it was at 43, lots of times it was down to 2, now it's generally up to 6. I'll see how it does, especially if it rains, and yes the trees really cover the antenna. I am getting 30-40 or more dBc however which is what I had when it was more in the clear. I can move it to the west about 30' on the chimney where my UHF/VHF beams are and it's a lot more open straight up and especially to the south. The position where it is now is just real convenient and it's only maybe 25' from the unit. Plus I didn't have to get up on that part of the roof that's 7 in 12. Yes, I notice the gis for our county seems to have a slightly different co-ordinate system, they don't line up with google or the GPS which seem to agree as far as I can zoom in on our location. I'd say the GPS and google are within a foot or 2. I guess I can just turn off the temp chart if it's not going to report right and stop looking/worrying about it. As long as the green lock light is on. I wonder if I could trick the Nortel unit into thinking it's seeing the CM though, so the top green light would come on instead of the yellow one. But that doesn't matter. Thanks for all your help, I'll hang around for a while. Dave N3DT ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi Your temperature plots look like mine. I suspect the other unit has a broken temperature detection chip. I've seen that happen on TBolts. Bob On Sep 9, 2013, at 10:44 PM, Arthur Dent wrote: > I have a slightly earlier version, or a close cousin, of the NTBW50AA that > I modified and I've posted photos of it on this list before: > http://i906.photobucket.com/albums/ac262/rjb1998/NTPB15AA05.jpg > > The LH plot from the NTBW50AA by quartz55 doesn't look quite right. Here > is a LH plot from my NTPB15AA unit with most of the scale factors set the > same as the scale factor in the plot from the NTBW50AA to make it easier > to compare. > http://i906.photobucket.com/albums/ac262/rjb1998/NTPB15A_zps19b3bd33.jpg > > If you look at the temp plot from my unit it has small steps and is what I'd > expect to see. The plot from the NTBW50AA looks like it has some smaller > steps but it looks like it hits a limit at 36.750 and doesn't go beyond that > value, which isn't right. It looks like a higher order bit is being turned on > and off randomly causing the large apparent jump in temp, which > probably isn't really happening because some of the other traces would > be affected by any real jump that large. You could just ignore it because it > would probably only have an effect during carryover. > > The NTBW50AA oscillator probably hasn't settled down yet because the > DAC voltage is changing a lot more than mine and the 10Mhz doesn't look > anywhere near as stable. The design of the 2 units appears nearly identical > so I'd expect similar performance. Also the OSC ADEV at 1 tau isn't close > to what mine appears to be. That may improve after the unit has been on > for a month or so but the temp plot just doesn't look right so the sensor may > be bad. > > -Arthur > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi On Sep 9, 2013, at 10:31 PM, quartz55 wrote: > OK, did a bit more reading. I already understand the difference between > accuracy and stability however. > > I thought ADEV was some sort of measurement of accuracy, but I understand now > it is a measure of stability over time. I'm supposing now that I can assume > that the best frequency accuracy I can imagine is what is specked in the book > for the unit, <.8x10^-10. ADEV as calculated is a fine thing. The next issue is that you are not doing the measurement that goes into the calculation the right way in a GPSDO like this. Even a stability measure needs a reference. In this case you don't have one. There is only one signal into the box (GPS). You need a second signal into it to do a comparison. There is no second signal present. LH is not doing anything wrong, it just does not have the data to do it completely right. > That should be good enough for me. Although most seem to say the GPSDO units > are good for .1Hz at 10GHz which I think would be 10^-13 no? If you are talking about a multi day average - sure. If you are talking about "what frequency am I at right now" not so much. The OCXO drifts / ages / wanders in much less than a day (or hour). You are doing pretty well to keep frequency under 1.0 x 10^-11. Some GPDSO designs are running fine when producing < 1.0x10^-10. In each case they likely would report very good numbers while looking only at themselves. These boxes were designed as time references rather than frequency references. The frequency requirements on a base station are much looser than the time requirements. The net result is that frequency can move around a bit as they push the pps to stay where it belongs. > > Yeah, I've read through the h...cpp and a lot of it is greek to me, I'm no > programmer, but I can pull a bunch of stuff out of it. But it doesn't > explain the acronyms or the meanings of them. There is no formal manual for LH and no magic help function. The archives of this list are probably the best place to find information on what this and that means. > > I've lowered the el mask to 20 and I get plenty of sats now. When it was at > 43, lots of times it was down to 2, now it's generally up to 6. You should be able to see 8 to 10 sats most of the time with a good location. I'd try to find someplace where you don't drop below 5. If you are running through trees, multi path may become an issue. Since multi path means a longer path delay it throw the time (and then frequency) of your GPSDO off. > I'll see how it does, especially if it rains, and yes the trees really cover > the antenna. I am getting 30-40 or more dBc however which is what I had when > it was more in the clear. I can move it to the west about 30' on the chimney > where my UHF/VHF beams are and it's a lot more open straight up and > especially to the south. The position where it is now is just real > convenient and it's only maybe 25' from the unit. Plus I didn't have to get > up on that part of the roof that's 7 in 12. The antenna has an amp in it. It should have around 36 db of gain. If you keep the cable loss below 20 db, distance should not matter. For most quad shield RG-6 that will let you run 200 feet. > > Yes, I notice the gis for our county seems to have a slightly different > co-ordinate system, they don't line up with google or the GPS which seem to > agree as far as I can zoom in on our location. I'd say the GPS and google > are within a foot or 2. There are a number of different systems. Google picked the same one as GPS. The way they do their maps, you can be off by 30 feet or … depending on where you are. > > I guess I can just turn off the temp chart if it's not going to report right > and stop looking/worrying about it. As long as the green lock light is on. > I wonder if I could trick the Nortel unit into thinking it's seeing the CM > though, so the top green light would come on instead of the yellow one. But > that doesn't matter. If you feed it the "right stuff" over the RS-485 links and cross tie the right lines to another uint, you can get the light to go out. Bob > > Thanks for all your help, I'll hang around for a while. > > Dave > N3DT > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
OK, did a bit more reading. I already understand the difference between accuracy and stability however. I thought ADEV was some sort of measurement of accuracy, but I understand now it is a measure of stability over time. I'm supposing now that I can assume that the best frequency accuracy I can imagine is what is specked in the book for the unit, <.8x10^-10. That should be good enough for me. Although most seem to say the GPSDO units are good for .1Hz at 10GHz which I think would be 10^-13 no? Yeah, I've read through the h...cpp and a lot of it is greek to me, I'm no programmer, but I can pull a bunch of stuff out of it. But it doesn't explain the acronyms or the meanings of them. I've lowered the el mask to 20 and I get plenty of sats now. When it was at 43, lots of times it was down to 2, now it's generally up to 6. I'll see how it does, especially if it rains, and yes the trees really cover the antenna. I am getting 30-40 or more dBc however which is what I had when it was more in the clear. I can move it to the west about 30' on the chimney where my UHF/VHF beams are and it's a lot more open straight up and especially to the south. The position where it is now is just real convenient and it's only maybe 25' from the unit. Plus I didn't have to get up on that part of the roof that's 7 in 12. Yes, I notice the gis for our county seems to have a slightly different co-ordinate system, they don't line up with google or the GPS which seem to agree as far as I can zoom in on our location. I'd say the GPS and google are within a foot or 2. I guess I can just turn off the temp chart if it's not going to report right and stop looking/worrying about it. As long as the green lock light is on. I wonder if I could trick the Nortel unit into thinking it's seeing the CM though, so the top green light would come on instead of the yellow one. But that doesn't matter. Thanks for all your help, I'll hang around for a while. Dave N3DT ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi On Sep 9, 2013, at 1:56 PM, "quartz55" wrote: > I moved the antenna, and did a new standard survey which took an hour and > then another 5 minutes or so to lock. The sats don't seem to be any less > right under the trees. You can see the antenna and trees here. > http://s251.photobucket.com/user/DogTi/library/time?sort=3&page=1 I'll let > it run and check on it now and then. Now if I had the XRef from VK3HZ. Unless I'm looking at the pictures wrong, you still have a lot of trees around the antenna. An ideal setup would be clear of obstruction to within 10 degrees of the horizon from about NE around through due S and back up to NW. It's rare that you get 100% of that ideal. If you are obstructed to > 45 degrees over most of that range the TBolt will be struggling at certain times of day. It'll struggle more when it's raining if the issue is trees. > > This thing seems much more accurate than the Nuvi we have. It puts the > antenna right on google where it actually is. That's more a matter of luck than anything else. Google maps isn't all that accurate. > I wish I could move this antenna around and do a bit of surveying with it. > I've got a couple property lines I'm not sure where it is except in a general > way. Your property line may or may not be defined in same reference frame GPS uses. You'll have to do some research on how it's defined. > Like the end points, but the line in between is about a half mile and > through the woods so you can't see line of sight. > > Can someone tell me where to go to read about the items that are listed in LH? The best way is to take a look at the source code. The other way is to just poke at it and see what comes up. Bob > > Dave > N3DT > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi On Sep 9, 2013, at 9:14 AM, "quartz55" wrote: > Wait a minute, Bob. I have an LPRO with good reported bulb voltatge. Are > you telling me this TBolt is no better than the Rb standard, as far as > stability and perhaps worse? It may not or may not be any more stable than your LPRO. You can not determine from the LH ADEV if it is or isn't. > And the frequency accuracy is also no better and both have to be compared to > a Cs or H Maser to be calibrated? Frequency accuracy and frequency stability are two different things. A source that swings +/- 2 ppb a day, but *average* to zero is accurate, but not stable. > I thought the GPS put out these precise second pulses that the TBolt would > measure over time and discipline the OCXO to those precision seconds over > time resulting in a variable (very small) but precise statistical frequency The "jitter" in the GPS pulses is the issue. Your GPS may be flopping around by many ns each second. That's many ppb before you do any averaging. > (unlike the Rb which is just very stable) ….. and thus is a good way to help answer "how stable is my GPSDO" ... > and thus having a reference back to NIST to a degree. (in my simplistic > language) > > Yes, I'm not fully understanding the Tau and ADEV I'm sure. I did read it's > the sq root of Allan variance. So the reported 1 Tau ADEV is not a > measurement of the variance of the frequency compared to the precise 1 second > marks over time? Assuming LH is reporting 10,000 second ADEV as "1 tau" then it's the ADEV correctly calculated for the GPS looking at the GPS disciplined OCXO. Since one is following the other it's like saying your counter is exactly right because it reads 10.0 MHz when you plug the reference output on the back of the counter into the input jack on the front of it. In order to do it correctly you need to compare to *independent* sources. > I thought if I had 1.0e-12 that was comparable to knowing it's within 1Hz at > a billion (10^12) Hz? Since it's ADEV you have a standard deviation of frequency change between 10,000 second samples of 1 ppt. Standard deviation isn't the same as mean. > > Should I reverse the &a command I did and let it run in the mode I got it in? > The 1 ADEV is back down to 1.6e-12 this morning. You can see the > screenshot here, > http://s251.photobucket.com/user/DogTi/media/time/20139-91229_zps7e475453.jpg.html > it looks like the temp is still jumping but for some reason the number of > sats has increased, a lot, maybe it's just the harmonic convergence. Again, you are checking your yardstick against it's self. Check it 10,000 times and average the results. The average error will be very small. That does not really say much about how accurate it is or if it changes length when the humidity goes up. > > Is that white line that runs around the center essentially the frequency > variance? And why do I have what appears to be multiple blue and red lines? White corresponds to the words in white just above the graph. It's running frequency. More or less, it's how much the frequency is jumping around. I have no idea why the dual ADEV lines. There is also a trace set to dark grey on your plot that shows the pps moving around. Bob > > So many questions, so little time. Anyhow, as soon as it warms up a bit and > I have my Earl Grey, I'm going to turn this thing off and go reset the > antenna and see what happens, I need to make a bracket which won't take long. > I just worry about climbing up the ladder these days since I had a herniated > disc removed and a spacer installed this spring. At least the pain is gone > and I'm not in a wheelchair. > > Dave > N3DT > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Wait a minute, Bob. I have an LPRO with good reported bulb voltatge. Are you telling me this TBolt is no better than the Rb standard, as far as stability and perhaps worse? And the frequency accuracy is also no better and both have to be compared to a Cs or H Maser to be calibtated? I thought the GPS put out these precise second pulses that the TBolt would measure over time and discipline the OCXO to those precision seconds over time resulting in a variable (very small) but precise statistical frequency (unlike the Rb which is just very stable) and thus having a reference back to NIST to a degree. (in my simplistic language) Yes, I'm not fully understanding the Tau and ADEV I'm sure. I did read it's the sq root of Allan variance. So the reported 1 Tau ADEV is not a measurement of the variance of the frequency compared to the precise 1 second marks over time? I thought if I had 1.0e-12 that was comparable to knowing it's within 1Hz at a billion (10^12) Hz? Should I reverse the &a command I did and let it run in the mode I got it in? The 1 ADEV is back down to 1.6e-12 this morning. You can see the screenshot here, http://s251.photobucket.com/user/DogTi/media/time/20139-91229_zps7e475453.jpg.html it looks like the temp is still jumping but for some reason the number of sats has increased, a lot, maybe it's just the harmonic convergence. Is that white line that runs around the center essentially the frequency variance? And why do I have what appears to be multiple blue and red lines? So many questions, so little time. Anyhow, as soon as it warms up a bit and I have my Earl Grey, I'm going to turn this thing off and go reset the antenna and see what happens, I need to make a bracket which won't take long. I just worry about climbing up the ladder these days since I had a herniated disc removed and a spacer installed this spring. At least the pain is gone and I'm not in a wheelchair. Dave N3DT ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi The only normal use for even second outputs is in a CDMA base station. The same is true of the multitude of 9.x MHz outputs coming out of the back of that unit. From what I have seen of LH, there's no real need to play with anything else on these units. The only thing you might do is to scan for unknown / undocumented commands with a chunk of custom code. Bob On Sep 8, 2013, at 9:43 PM, quartz55 wrote: > Thanks guys. That's all useful information, I think. I'm still trying to > understand the lingo. The temp trace is still whacking down, but not as much > as before. I guess it's way to early to start complaining about this unit. > The 1 tau is now at 6.4e-12 it seems to be going back up. I was sort of > hoping for around 1e-12, but still 6.4 is 6.4 Hz out of 1,000,000 MHz if I'm > doing my decimals right. And that's plenty good for me, it's still orders of > magnitude under the mHz range at even UHF. The green trace, DAC is still > drifting down, but nothing on the unit has changed, the yellow LED remains on > as well as the green lock LED. The switching supply is slightly warm, but > cooler than the OCXO by feel. I can't imagine either one of them is over > 90F. I could put the Fluke thermister on them if it's of any interest. I've > got the cover off of it for now. The cover will go back on, but the unit > will be in a well ventilated space and the temp is pretty constant in this > room. > > I've got a pipe right above the radio room for a UHF/VHF vertical and I'm > going to try mounting a bracket off that to put the antenna on tomorrow. > It'll be out of sight there from the deck but still a bit under the oaks. > Should I do the E command and save the config before I turn things off and > then do a detailed survey at the new position or just do a new survey when I > start up again? > > My Nortel unit has only the even seconds output. As far as I know I don't > have any use for the seconds output, I'm just looking for a good 10MHz ref. > > Is there any use to look at the Tboltmon.exe or is that a waste of time? > > Dave > N3DT > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi I think you may be looking at the ADEV and reading more into it than you should. It's a table of ADEV vs Tau. The longer you have data for, the larger Tau (seconds) it will display. It's not getting better as it displays more data it the table, it's just got more seconds of data. ADEV should be a measure of stability. In the case of a GPSDO, you have an OCXO that's locked to the GPS. As the GPS moves, the OCXO follows the GPS. There is no independent "referee" to let you know if things are moving in the right or wrong direction. Put another way, it's like looking at the reference on your counter by plugging it into the front of the counter. Because the OCXO always follows the GPS, the ADEV as shown will always get better with time. You are getting further and further inside the control loop. To really know what's going on with the GPSDO you need an independent standard to compare it to. Even a cheap Rb will help you figure out how stable the frequency really is. A Cs or a Hydrogen Maser would (of course) be better. Bob On Sep 8, 2013, at 5:51 PM, quartz55 wrote: > I did the &a command and it seems to have straightened out. I don't know > what I did but now it toggles from full screen to a window fine for now. It > changed the el and amu masks. I'll let it run overnight see how it is and > then try moving the antenna to what I think may be it's permanent position > and see if it works there. I goggled the Lat Lon and it puts the antenna > right on my deck where I have it. I notice the mouse acts erratically > sometimes, I have a laptop I may press into service for this thing but it's a > vista OS. > > I found lots of info in heather.cpp, but I wonder if the keyboard commands > aren't somewhere easier to find, other than the space bar. > > It's gone up to 3.63e-12 now. > > Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi Temperature stable to < 1/4 C for 2+ hours is pretty good for a normal home environment….. Bob On Sep 8, 2013, at 8:07 PM, Mark Sims wrote: > It is reporting temperature just fine. It probably has the "new" revision > temperature sensor chip that the firmware does not read the high res > temperature properly. Also, one version of those Nortel units (don't > remember which one) doesn't do high res temp readings even with the old rev > temp chip. > > The plots in Lady Heather default to auto-scaling and auto-centering with > each update. That can cause the plots to appear to jump around as new data > come in. > > And the F11 full screen mode toggle is known to not work with many > monitor/window size combinations. > > The Nortel units don't save the oscillator damping/gain/time constant > settings in EEPROM (at least with any of the documented commands). > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi Ok, the yellow trace (temperature) still does not look right. Either you have a lab grade temp chamber to keep stuff in, or it's just not reporting temperature. Units and limits and meaning change for ADEV depending on the tau. If you are looking at 1 tau (which I thought you were) then it's a much higher level of noise and much less accuracy than a tau of several thousand seconds. Bob On Sep 8, 2013, at 6:46 PM, quartz55 wrote: > Here's a screen shot of when I did the &a command. It went through a bit of > glitches at the start you can see on the left of the plot and then pretty > much straightened out. Even the green line has stabalized a lot. > http://s251.photobucket.com/user/DogTi/media/time/20139-82237_zps85bd9fe7.jpg.html?sort=3&o=0 > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Dave, When you kick off LH "Auto tune OSC parameters" LH changes the elevation mask too. Oh yeah I was going to say, 3.63e-12 is getting awfully close to e-13, good stuff. Bob will tell you it's all pretty much mumbo jumbo past that point, you have one tight GPSDO now. And I seem to have all this back to front,, Is yours the new single board units (GPTSM) or do you have the GPSR? The GPSR has 1PPS but the GPTSM has even second only. (@ http://www.ko4bb.com/manuals/index.php?dir=05)_GPS_Timing/Nortel_GPS ) Its all clear as mud anyway, I bet there is 1PPS lurking on there somewhere. Some OEM could not live without it.. Check heathmsc.cpp for the fun cookies, let's be frank, life's too much of a drag without some fun :) Even if the fun is your little brother being eaten by the pigs (whatever that means ;) And to be Frank, I'd have to change my name (Boom-Boom) --marki -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of quartz55 Sent: Monday, 9 September 2013 7:52 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] New NTBW50AA I did the &a command and it seems to have straightened out. I don't know what I did but now it toggles from full screen to a window fine for now. It changed the el and amu masks. I'll let it run overnight see how it is and then try moving the antenna to what I think may be it's permanent position and see if it works there. I goggled the Lat Lon and it puts the antenna right on my deck where I have it. I notice the mouse acts erratically sometimes, I have a laptop I may press into service for this thing but it's a vista OS. I found lots of info in heather.cpp, but I wonder if the keyboard commands aren't somewhere easier to find, other than the space bar. It's gone up to 3.63e-12 now. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi Once you get down into the <= 4.0x10^-12 range on ADEV it's all pretty meaningless with that unit. The math is correct, but the data it's basing the calculations on really does not have enough accuracy. Bob On Sep 8, 2013, at 5:51 PM, "quartz55" wrote: > I did the &a command and it seems to have straightened out. I don't know > what I did but now it toggles from full screen to a window fine for now. It > changed the el and amu masks. I'll let it run overnight see how it is and > then try moving the antenna to what I think may be it's permanent position > and see if it works there. I goggled the Lat Lon and it puts the antenna > right on my deck where I have it. I notice the mouse acts erratically > sometimes, I have a laptop I may press into service for this thing but it's a > vista OS. > > I found lots of info in heather.cpp, but I wonder if the keyboard commands > aren't somewhere easier to find, other than the space bar. > > It's gone up to 3.63e-12 now. > > Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi Before you run into it: 1) Normally the "oscillator tune" function in LH does not work correctly on that unit. Either the firmware does not allow filter updates (likely) or they use a different syntax than the one used by LH. 2) Best performance will come from a > 48 hour survey. LH is quite happy to do this for you. It's only worth doing after you decide on a permanent antenna location. 3) These modules normally operated with some moving air. At the very least, don't block up all the vents and stack a bunch of stuff above and below them. The main thing to watch out for is the temperature of the DC-DC converter brick. A touch test is perfectly adequate to tell you if it's getting hot. Bob On Sep 8, 2013, at 1:59 PM, quartz55 wrote: > I'm getting 1.55e-12 ADEV at this point, about 20 hours into it. > > Why does the yellow line keep going full up and down, although not all the > time? > > Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi The yellow line in your last screen shot was temperature. There are a couple of possibilities: 1) You are operating the unit in an oil bath 2) LH isn't real happy with the data format of your temperature sensor via your firmware 3) The temperature sensor is broke Based on the screen shot I'd bet on 3…. Bob On Sep 8, 2013, at 1:59 PM, quartz55 wrote: > I'm getting 1.55e-12 ADEV at this point, about 20 hours into it. > > Why does the yellow line keep going full up and down, although not all the > time? > > Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
I'm getting 1.55e-12 ADEV at this point, about 20 hours into it. Why does the yellow line keep going full up and down, although not all the time? Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi Yes indeed you should get below (thus the sub) the numbers I indicated. At the point I made the comment, he was at 10X that level. Bob On Sep 8, 2013, at 12:32 PM, Said Jackson wrote: > Bob, > > Sorry, but an ADEV of 2ns/s at 1s is pretty bad drift for a GPSDO or even a > free running low cost TCXO.. > > I think a TCXO based unit should be in the 5E-011 to 1E-010 range and a good > OCXO unit should achieve better than 5 E-012 at 1s. Even a cheap $150 > Thunderbolt can beat the latter easily. > > Remember that a 1s ADEV doesn't measure static frequency error, it measures > how the frequency varies from second to second. So 2E-09 at 1s means the > frequency is going up and down about +/-1ppb or more every second. > > Thats quite unstable even for the worst references or oscillators out there. > > Something is not working right if Dave sees 10E-09 at 1s... > > Bye, > Said > > Sent From iPhone > > On Sep 7, 2013, at 18:14, Bob Camp wrote: > >> Hi >> >> A reasonable ADEV for tau =1 is in the sub 2.0 x10^-9 range (or 2,000e-009). >> >> Bob >> >> On Sep 7, 2013, at 7:27 PM, "quartz55" wrote: >> >>> Thanks Mark, yeah, I think I'm getting the hang of this thing. The ADEV is >>> down to 1.032e-008 by this point. >>> >>> I think the red light was on because it was going out of lock, it couldn't >>> find the satellites until I did a survey. Then things started coming into >>> perspective when it found my position. At one point the osc was listed as >>> bad. I just turned it off and started again and it seems fine now. >>> >>> Nothing seems even warm on the board with 30VDC going into it. That brick >>> I had, I couldn't get the voltage out of it, so I canned that one. I think >>> I can find a smaller supply than I've got though, this one is an old 10A >>> 12V linear regulated supply that the regulator went out in. >>> >>> I haven't had this much fun since the pigs ate my little brother. >>> >>> Dave >>> ___ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Bob, Sorry, but an ADEV of 2ns/s at 1s is pretty bad drift for a GPSDO or even a free running low cost TCXO.. I think a TCXO based unit should be in the 5E-011 to 1E-010 range and a good OCXO unit should achieve better than 5 E-012 at 1s. Even a cheap $150 Thunderbolt can beat the latter easily. Remember that a 1s ADEV doesn't measure static frequency error, it measures how the frequency varies from second to second. So 2E-09 at 1s means the frequency is going up and down about +/-1ppb or more every second. Thats quite unstable even for the worst references or oscillators out there. Something is not working right if Dave sees 10E-09 at 1s... Bye, Said Sent From iPhone On Sep 7, 2013, at 18:14, Bob Camp wrote: > Hi > > A reasonable ADEV for tau =1 is in the sub 2.0 x10^-9 range (or 2,000e-009). > > Bob > > On Sep 7, 2013, at 7:27 PM, "quartz55" wrote: > >> Thanks Mark, yeah, I think I'm getting the hang of this thing. The ADEV is >> down to 1.032e-008 by this point. >> >> I think the red light was on because it was going out of lock, it couldn't >> find the satellites until I did a survey. Then things started coming into >> perspective when it found my position. At one point the osc was listed as >> bad. I just turned it off and started again and it seems fine now. >> >> Nothing seems even warm on the board with 30VDC going into it. That brick I >> had, I couldn't get the voltage out of it, so I canned that one. I think I >> can find a smaller supply than I've got though, this one is an old 10A 12V >> linear regulated supply that the regulator went out in. >> >> I haven't had this much fun since the pigs ate my little brother. >> >> Dave >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi One of many ways to compare the two frequencies: Run one into the trigger input on your scope. Run the other into the main channel on the scope. Crank the sweep up as fast as practical. Get out the clock to start monitoring elapsed time. A nanosecond per second is 1 ppb, you should be able to get it to 0.01 ppb. That would be a nanosecond per 100 seconds. It's a lot more likely you will be looking at 10 ns per 10 seconds and 10 ns per 1,000 seconds, but the approach is the same. Bob On Sep 8, 2013, at 11:36 AM, quartz55 wrote: > I like that lambda supply Bob, nice size compared to the slug I'm using. > > It's at 5.6e-10 this morning. I think I'll move the antenna back to the > original site and see if it works there, it's out in the middle of the deck > right now and I'm sure the wifey won't like it staying there. > > The switching supply module in it is Datel TPB-5/5-12/1-Q48, > > One question with LH. When it's full screen and I hit F11, it minimizes to a > tiny bar. And the only thing it will do from there is full screen and will > only toggle between the two. How do I get it back to a normal window size? > Used to toggle between a window and full screen. > > It's putting out +12.4dBm and with my LPRO driving my service monitor, I > could split it and still have plenty dB, it's reading 1000Hz, that's the > finest resolution on the service monitor in rx mode, 1Hz. Seems to be a good > filtered 10MHz with no harmonics that I can see in the service monitor, > haven't tried it into a rx yet. The LPRO had all sorts of harmonics. > > How do I compare the Nortel to my LPRO? Feed them through a combiner into a > scope? What am I looking for in trying to calibrate the LPRO? That's the > second reason I got this thing. > > I'm waiting for the XRef I bought from VK3HZ so I can hook this thing up to > my TS-2000, that was my primary objective. TS-2000 wasn't bad but when the > fan comes on it wanders around 4Hz at 144 and that's with a bunch of cotton > pads stuck around the ref osc. The long term drift was more than 4 hz too. > I'd like to be able to read mHz with SpecLab when I get set up. I realize > the DSP will throw it off, but hopefully it'll be consistent. > > You can see my latest screenshot and the rats nest on the bench showing the > mongo PS. I need to get this thing sorted and put in it's home. > > Dave > N3DT > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi That sounds about right. Current would double at 24 volts / power would be the same. A cheap 50W power supply at either voltage would run a *lot* of GPSDO's. Looks like a http://www.digikey.com/product-detail/en/LS50-24/285-1820-ND/1918831 for $21.64 would do pretty well. Bob On Sep 8, 2013, at 9:32 AM, gandal...@aol.com wrote: > Whoops, you're quite right !! > > The figures I quoted were the maximum taken straight from the manual, as I > happened to have it open anyway, and whilst I did think the startup current > seemed rather high didn't stop to check my own notes as I was in a bit of > a rush, that'll teach me:-) > > Checking back now, what I actually measured with a 48 Volt supply was > 305mA from a cold start and 147mA warmed up and running, which equates to > approximately 15 and 7 Watts respectively. > > Regards > > Nigel > GM8PZR > > > In a message dated 08/09/2013 13:48:48 GMT Daylight Time, li...@rtty.us > writes: > > Hi > > The power swing as the OCXO warms up is a bit less than 10 watts. > > Bob > > On Sep 8, 2013, at 4:08 AM, gandal...@aol.com wrote: > >> Hi Dave, >> >> Just taking a short break from a major data recovery exercise to add a >> couple of comments to the replies you've already received. >> >> The part number for the DC to DC convertor should be written on the side > of >> it, although it might be awkward to see if facing the inside of the case. >> On my uncased Ebay boards from fluke.l it's visible as being a Datel >> TBP-5/5-12/1-Q48 so I suspect yours will be very similar. Google that > number to >> bring up a datasheet. >> If yours is the same it will handle an input range of 18 to 72 volts, > 19.5 >> via the diode block would have been low but 30 is fine and 48 would be >> better, as has already been noted the convertor input current is based > on the >> total output power, which is pretty much independant of input voltage, > so >> the higher the input voltage the lower the input current. >> >> The generic manual set for the Trimble Nortel boards is in Didier's > manuals >> collection >> _http://www.ko4bb.com/manuals/index.php?dir=05%29_GPS_Timing/Nortel_GPS_ > >> (http://www.ko4bb.com/manuals/index.php?dir=05)_GPS_Timing/Nortel_GPS) >> >> The Nortel GPSTM General Specification document will give more > information >> on the current requirements but you should allow for approximately 75 > watts >> input power during oscillator warm up and 22 Watts when settled. >> >> The longer the board is left up and running the better, permanently > powered >> is best for long term performance, and especially the first time round >> whilst it sorts out its new location. >> The location is stored automatically to the board, either by the board >> itself or under instruction from Lady Heather not sure which, but as > your >> posted LH plot shows your position has now been stored. With the > position stored >> I've found the time for acquisition and oscillator locking can be as >> little as 10 minutes. >> >> Further to Mark's comment about the backplane connector, the manual also > >> shows the pinout data for that and I don't see any reference to 1PPS. >> >> Regards >> >> Nigel >> GM8PZR >> >> >> >> >> In a message dated 08/09/2013 00:27:36 GMT Daylight Time, >> quart...@hughes.net writes: >> >> Thanks Mark, yeah, I think I'm getting the hang of this thing. The > ADEV >> is down to 1.032e-008 by this point. >> >> I think the red light was on because it was going out of lock, it > couldn't >> find the satellites until I did a survey. Then things started coming > into >> perspective when it found my position. At one point the osc was listed > as >> bad. I just turned it off and started again and it seems fine now. >> >> Nothing seems even warm on the board with 30VDC going into it. That > brick >> I had, I couldn't get the voltage out of it, so I canned that one. I >> think I can find a smaller supply than I've got though, this one is an > old 10A >> 12V linear regulated supply that the regulator went out in. >> >> I haven't had this much fun since the pigs ate my little brother. >> >> Dave >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ > time-nut
Re: [time-nuts] New NTBW50AA
Whoops, you're quite right !! The figures I quoted were the maximum taken straight from the manual, as I happened to have it open anyway, and whilst I did think the startup current seemed rather high didn't stop to check my own notes as I was in a bit of a rush, that'll teach me:-) Checking back now, what I actually measured with a 48 Volt supply was 305mA from a cold start and 147mA warmed up and running, which equates to approximately 15 and 7 Watts respectively. Regards Nigel GM8PZR In a message dated 08/09/2013 13:48:48 GMT Daylight Time, li...@rtty.us writes: Hi The power swing as the OCXO warms up is a bit less than 10 watts. Bob On Sep 8, 2013, at 4:08 AM, gandal...@aol.com wrote: > Hi Dave, > > Just taking a short break from a major data recovery exercise to add a > couple of comments to the replies you've already received. > > The part number for the DC to DC convertor should be written on the side of > it, although it might be awkward to see if facing the inside of the case. > On my uncased Ebay boards from fluke.l it's visible as being a Datel > TBP-5/5-12/1-Q48 so I suspect yours will be very similar. Google that number to > bring up a datasheet. > If yours is the same it will handle an input range of 18 to 72 volts, 19.5 > via the diode block would have been low but 30 is fine and 48 would be > better, as has already been noted the convertor input current is based on the > total output power, which is pretty much independant of input voltage, so > the higher the input voltage the lower the input current. > > The generic manual set for the Trimble Nortel boards is in Didier's manuals > collection > _http://www.ko4bb.com/manuals/index.php?dir=05%29_GPS_Timing/Nortel_GPS_ > (http://www.ko4bb.com/manuals/index.php?dir=05)_GPS_Timing/Nortel_GPS) > > The Nortel GPSTM General Specification document will give more information > on the current requirements but you should allow for approximately 75 watts > input power during oscillator warm up and 22 Watts when settled. > > The longer the board is left up and running the better, permanently powered > is best for long term performance, and especially the first time round > whilst it sorts out its new location. > The location is stored automatically to the board, either by the board > itself or under instruction from Lady Heather not sure which, but as your > posted LH plot shows your position has now been stored. With the position stored > I've found the time for acquisition and oscillator locking can be as > little as 10 minutes. > > Further to Mark's comment about the backplane connector, the manual also > shows the pinout data for that and I don't see any reference to 1PPS. > > Regards > > Nigel > GM8PZR > > > > > In a message dated 08/09/2013 00:27:36 GMT Daylight Time, > quart...@hughes.net writes: > > Thanks Mark, yeah, I think I'm getting the hang of this thing. The ADEV > is down to 1.032e-008 by this point. > > I think the red light was on because it was going out of lock, it couldn't > find the satellites until I did a survey. Then things started coming into > perspective when it found my position. At one point the osc was listed as > bad. I just turned it off and started again and it seems fine now. > > Nothing seems even warm on the board with 30VDC going into it. That brick > I had, I couldn't get the voltage out of it, so I canned that one. I > think I can find a smaller supply than I've got though, this one is an old 10A > 12V linear regulated supply that the regulator went out in. > > I haven't had this much fun since the pigs ate my little brother. > > Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi The power swing as the OCXO warms up is a bit less than 10 watts. Bob On Sep 8, 2013, at 4:08 AM, gandal...@aol.com wrote: > Hi Dave, > > Just taking a short break from a major data recovery exercise to add a > couple of comments to the replies you've already received. > > The part number for the DC to DC convertor should be written on the side of > it, although it might be awkward to see if facing the inside of the case. > On my uncased Ebay boards from fluke.l it's visible as being a Datel > TBP-5/5-12/1-Q48 so I suspect yours will be very similar. Google that number > to > bring up a datasheet. > If yours is the same it will handle an input range of 18 to 72 volts, 19.5 > via the diode block would have been low but 30 is fine and 48 would be > better, as has already been noted the convertor input current is based on > the > total output power, which is pretty much independant of input voltage, so > the higher the input voltage the lower the input current. > > The generic manual set for the Trimble Nortel boards is in Didier's manuals > collection > _http://www.ko4bb.com/manuals/index.php?dir=05%29_GPS_Timing/Nortel_GPS_ > (http://www.ko4bb.com/manuals/index.php?dir=05)_GPS_Timing/Nortel_GPS) > > The Nortel GPSTM General Specification document will give more information > on the current requirements but you should allow for approximately 75 watts > input power during oscillator warm up and 22 Watts when settled. > > The longer the board is left up and running the better, permanently powered > is best for long term performance, and especially the first time round > whilst it sorts out its new location. > The location is stored automatically to the board, either by the board > itself or under instruction from Lady Heather not sure which, but as your > posted LH plot shows your position has now been stored. With the position > stored > I've found the time for acquisition and oscillator locking can be as > little as 10 minutes. > > Further to Mark's comment about the backplane connector, the manual also > shows the pinout data for that and I don't see any reference to 1PPS. > > Regards > > Nigel > GM8PZR > > > > > In a message dated 08/09/2013 00:27:36 GMT Daylight Time, > quart...@hughes.net writes: > > Thanks Mark, yeah, I think I'm getting the hang of this thing. The ADEV > is down to 1.032e-008 by this point. > > I think the red light was on because it was going out of lock, it couldn't > find the satellites until I did a survey. Then things started coming into > perspective when it found my position. At one point the osc was listed as > bad. I just turned it off and started again and it seems fine now. > > Nothing seems even warm on the board with 30VDC going into it. That brick > I had, I couldn't get the voltage out of it, so I canned that one. I > think I can find a smaller supply than I've got though, this one is an old > 10A > 12V linear regulated supply that the regulator went out in. > > I haven't had this much fun since the pigs ate my little brother. > > Dave > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] New NTBW50AA
Hi Dave, Just taking a short break from a major data recovery exercise to add a couple of comments to the replies you've already received. The part number for the DC to DC convertor should be written on the side of it, although it might be awkward to see if facing the inside of the case. On my uncased Ebay boards from fluke.l it's visible as being a Datel TBP-5/5-12/1-Q48 so I suspect yours will be very similar. Google that number to bring up a datasheet. If yours is the same it will handle an input range of 18 to 72 volts, 19.5 via the diode block would have been low but 30 is fine and 48 would be better, as has already been noted the convertor input current is based on the total output power, which is pretty much independant of input voltage, so the higher the input voltage the lower the input current. The generic manual set for the Trimble Nortel boards is in Didier's manuals collection _http://www.ko4bb.com/manuals/index.php?dir=05%29_GPS_Timing/Nortel_GPS_ (http://www.ko4bb.com/manuals/index.php?dir=05)_GPS_Timing/Nortel_GPS) The Nortel GPSTM General Specification document will give more information on the current requirements but you should allow for approximately 75 watts input power during oscillator warm up and 22 Watts when settled. The longer the board is left up and running the better, permanently powered is best for long term performance, and especially the first time round whilst it sorts out its new location. The location is stored automatically to the board, either by the board itself or under instruction from Lady Heather not sure which, but as your posted LH plot shows your position has now been stored. With the position stored I've found the time for acquisition and oscillator locking can be as little as 10 minutes. Further to Mark's comment about the backplane connector, the manual also shows the pinout data for that and I don't see any reference to 1PPS. Regards Nigel GM8PZR In a message dated 08/09/2013 00:27:36 GMT Daylight Time, quart...@hughes.net writes: Thanks Mark, yeah, I think I'm getting the hang of this thing. The ADEV is down to 1.032e-008 by this point. I think the red light was on because it was going out of lock, it couldn't find the satellites until I did a survey. Then things started coming into perspective when it found my position. At one point the osc was listed as bad. I just turned it off and started again and it seems fine now. Nothing seems even warm on the board with 30VDC going into it. That brick I had, I couldn't get the voltage out of it, so I canned that one. I think I can find a smaller supply than I've got though, this one is an old 10A 12V linear regulated supply that the regulator went out in. I haven't had this much fun since the pigs ate my little brother. Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
