[time-nuts] Rubidium Oscillators
good members What are your opinions on the usage of Rubidium Frequency Standards - in the sense - should they be used for short periods of time (until they reach a stable state) as a check only,or is it permissible to run them continuously? In other words, is the lamp (which is the expensive replacement item), deteriorating on a linear scale, and how fast ? I trust that this isn't a stupid question, as it was put to me recently and I was unsure of the answer. I currently feed my Racal 9480 TF Mainframe continuously with the 10 MHz signal from a Ball Efratom Rubidium Standard, assuming that its superior to the OCXO built into the 9480. Or would it be more sensible cost wise, to adjust the OCXO against it on a regular basis? Like many other such matters, probably the answer is obvious - but what do you say ? regards Roy ___ 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] Racal-Dana 1992 switches
David McGaw wrote: Does anyone know of a source of push-button switches for the Racal-Dana 1992? I have one that over half are bad. No luck from Racal-Dana or their service house. The original makers of that switch (Omron?) stopped making them years ago. I wonder why? The last time I did this I found a switch at Jameco that was a near exact replacement. The only difference was that the button was a little too loose a fit and needed a dab of epoxy inside to hold it firmly in place. These have been working in mine now for at least five years. The type I used was KIE22 (29 cents each in 100s), however the ones I got then with a cross section shape blue plunger do not look exactly the same as the ones pictured in the current on line catalog. Some further research is indicated obviously... Once they start to go they will all need to be replaced, I'm afraid. Good luck, Dan ___ 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] Racal-Dana 1992 switches
Does anyone know of a source of push-button switches for the Racal-Dana 1992? I have one that over half are bad. No luck from Racal-Dana or their service house. Thanks, David ___ 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] Racal-Dana 1992 switches
Had the same trouble!!! bought a junk racal unit (they have several models) for $10 stole the switches from it!!! Sad way to send a unit to the scrap BIN!!! The unit is EXCELLENT well worth the repair effort Norm David McGaw [EMAIL PROTECTED] wrote: Does anyone know of a source of push-button switches for the Racal-Dana 1992? I have one that over half are bad. No luck from Racal-Dana or their service house. Thanks, David ___ 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] Motorola GPS + 5 MHz oscillator ?
I have a friend who has two of the surplus (telephone Co. ?) timing receivers. That use a Motorola (A111219115) GPS receiver and a ovenized 5 MHz oscillator It has external connectors for 5 MHz., 1 PPS, -48Volts, RS232, and the Antenna. He has the matching Antenna which is marked 5 Volt and looks like it has a helix inside. What I want to do is get one of them running so I need to find the correct commands to set the Lat and Long. and read the status messages. Anyone recognize this equipment? Bill K7NOM ___ 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] Motorola GPS + 5 MHz oscillator ?
Can you get some photos so we can try to recognise it? Rob K -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bill Janssen Sent: 10 March 2008 18:30 To: Discussion of precise time and frequency measurement Subject: [time-nuts] Motorola GPS + 5 MHz oscillator ? I have a friend who has two of the surplus (telephone Co. ?) timing receivers. That use a Motorola (A111219115) GPS receiver and a ovenized 5 MHz oscillator It has external connectors for 5 MHz., 1 PPS, -48Volts, RS232, and the Antenna. He has the matching Antenna which is marked 5 Volt and looks like it has a helix inside. What I want to do is get one of them running so I need to find the correct commands to set the Lat and Long. and read the status messages. Anyone recognize this equipment? Bill K7NOM ___ 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] counter
Hello, I have some other Time and frequency stuff for some time nuts, before I place it on ebay. A Stanford Research SR620 Time interval counter including option 1 (Oven Osc.) Well working and timebase adjusted. A Vectron Crystal Oscillator CO-811B-1 10 MHz is a replacemant for the HP 10811 Oscillator Please contact me at [EMAIL PROTECTED] . for more information. Best regards, Erik ___ 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] Motorola GPS + 5 MHz oscillator ?
Bill, This one of the old Motorola Basic receivers. Is it in a plastic box or an aluminum one? Doesn't matter, just curious. Many years ago I created a PDF version of the old VP command set which is supported by the Basic. I think Jason Rabel has a copy on his website. Jason, are you out there? Can't remember your URL. For instant gratification I would recommend you download TAC32 from Rick Hambly's website:www.cnssystems.com (I think it is on the TAPR site too. TAC32 will automatically go through all of the messages on power-up needed to identify the receiver. Once you know that we can make a pretty good guess on which commands it will support. It's also a quick way to see if the receiver even functions. Randy Warner -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bill Janssen Sent: Monday, March 10, 2008 11:30 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Motorola GPS + 5 MHz oscillator ? I have a friend who has two of the surplus (telephone Co. ?) timing receivers. That use a Motorola (A111219115) GPS receiver and a ovenized 5 MHz oscillator It has external connectors for 5 MHz., 1 PPS, -48Volts, RS232, and the Antenna. He has the matching Antenna which is marked 5 Volt and looks like it has a helix inside. What I want to do is get one of them running so I need to find the correct commands to set the Lat and Long. and read the status messages. Anyone recognize this equipment? Bill K7NOM ___ 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] counter
Hello Eric, how much are you asking for the SR620? thanks, Said In a message dated 3/10/2008 12:31:50 Pacific Daylight Time, [EMAIL PROTECTED] writes: I have some other Time and frequency stuff for some time nuts, before I place it on ebay. A Stanford Research SR620 Time interval counter including option 1 (Oven Osc.) Well working and timebase adjusted. A Vectron Crystal Oscillator CO-811B-1 10 MHz is a replacemant for the HP 10811 Oscillator **It's Tax Time! Get tips, forms, and advice on AOL Money Finance. (http://money.aol.com/tax?NCID=aolprf000301) ___ 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] Motorola GPS + 5 MHz oscillator ?
randy warner wrote: Bill, This one of the old Motorola Basic receivers. Is it in a plastic box or an aluminum one? Doesn't matter, just curious. Many years ago I created a PDF version of the old VP command set which is supported by the Basic. I think Jason Rabel has a copy on his website. Jason, are you out there? Can't remember your URL. For instant gratification I would recommend you download TAC32 from Rick Hambly's website:www.cnssystems.com (I think it is on the TAPR site too. TAC32 will automatically go through all of the messages on power-up needed to identify the receiver. Once you know that we can make a pretty good guess on which commands it will support. It's also a quick way to see if the receiver even functions. Randy Warner Correct URL is: http://www.cnssys.com/ Bruce ___ 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] Motorola GPS + 5 MHz oscillator ?
Thanks Bruce, I guess I have been away from the GPS timing sector for too long. I'm sure I will hear from Rick... Randy -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bruce Griffiths Sent: Monday, March 10, 2008 1:25 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Motorola GPS + 5 MHz oscillator ? randy warner wrote: Bill, This one of the old Motorola Basic receivers. Is it in a plastic box or an aluminum one? Doesn't matter, just curious. Many years ago I created a PDF version of the old VP command set which is supported by the Basic. I think Jason Rabel has a copy on his website. Jason, are you out there? Can't remember your URL. For instant gratification I would recommend you download TAC32 from Rick Hambly's website:www.cnssystems.com (I think it is on the TAPR site too. TAC32 will automatically go through all of the messages on power-up needed to identify the receiver. Once you know that we can make a pretty good guess on which commands it will support. It's also a quick way to see if the receiver even functions. Randy Warner Correct URL is: http://www.cnssys.com/ Bruce ___ 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] Component level 1:2 splitter
Guys, I need to come up with a 0db little splitter to route 1 antenna into 2 GPS receivers. To keep the isolation up I want to use an active splitter instead of a passive one. I suppose I could use a passive splitter followed by two LNA's (one to each receiver), but I would then have to add a lot of attenuation to knock the signal back down. I suppose it would work, but the noise factor sure wouldn't be optimum. Does anyone out there know of a single/dual IC solution to this? Everything I have found LNA wise is in the 10-30 dB range. Note that this will be a board mounted circuit and I don't have to worry about connectors, etc. I'm hoping to find a little solution that I can cover with one of Laird's standard shield cans. Thanks, Randy Warner ___ 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] Component level 1:2 splitter
randy warner wrote: Guys, I need to come up with a 0db little splitter to route 1 antenna into 2 GPS receivers. To keep the isolation up I want to use an active splitter instead of a passive one. I suppose I could use a passive splitter followed by two LNA's (one to each receiver), but I would then have to add a lot of attenuation to knock the signal back down. I suppose it would work, but the noise factor sure wouldn't be optimum. Does anyone out there know of a single/dual IC solution to this? Everything I have found LNA wise is in the 10-30 dB range. Note that this will be a board mounted circuit and I don't have to worry about connectors, etc. I'm hoping to find a little solution that I can cover with one of Laird's standard shield cans. Thanks, Randy Warner Randy The only solution that springs to mind is to amplify split/attenuate amplify attenuate. If one uses low noise amplifiers and maintains a net gain before the output attenuator then the noise figure can be kept reasonably low. This requires an input amplifier followed by a splitter and possibly an attenuator followed by an amplifier with an output attenuator for each of the 2 splitter outputs. The output attenuators will also increase the isolation by a few dB. Bruce ___ 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] Component level 1:2 splitter
In message [EMAIL PROTECTED], Bruce Griffiths writes: I need to come up with a 0db little splitter to route 1 antenna into 2 GPS receivers. To keep the isolation up I want to use an active splitter instead of a passive one. I have no idea if it is feasible at GPS frequencies, but two common-gate amplifiers both feeding of the input might be workable. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Component level 1:2 splitter
Bruce, I'm afraid I have to agree. I just can't seem to find an easy way to do this. I suppose I could cut one of my HP splitters apart, but that would be rather ugly and costly. ;-) Randy -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bruce Griffiths Sent: Monday, March 10, 2008 3:02 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Component level 1:2 splitter randy warner wrote: Guys, I need to come up with a 0db little splitter to route 1 antenna into 2 GPS receivers. To keep the isolation up I want to use an active splitter instead of a passive one. I suppose I could use a passive splitter followed by two LNA's (one to each receiver), but I would then have to add a lot of attenuation to knock the signal back down. I suppose it would work, but the noise factor sure wouldn't be optimum. Does anyone out there know of a single/dual IC solution to this? Everything I have found LNA wise is in the 10-30 dB range. Note that this will be a board mounted circuit and I don't have to worry about connectors, etc. I'm hoping to find a little solution that I can cover with one of Laird's standard shield cans. Thanks, Randy Warner Randy The only solution that springs to mind is to amplify split/attenuate amplify attenuate. If one uses low noise amplifiers and maintains a net gain before the output attenuator then the noise figure can be kept reasonably low. This requires an input amplifier followed by a splitter and possibly an attenuator followed by an amplifier with an output attenuator for each of the 2 splitter outputs. The output attenuators will also increase the isolation by a few dB. Bruce ___ 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] Component level 1:2 splitter
Dan, Thanks for the info. It looks like Mini-Circuits little BP2G IC should work well enough. 3dB of loss SHOULDN'T bother anything, the Novatel L1 CP receivers we use here are almost deaf... So long as the isolation stays up in the high 20's and I put buffers on all ports I should be OK. Randy -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Dan Rae Sent: Monday, March 10, 2008 3:23 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Component level 1:2 splitter randy warner wrote: Guys, I need to come up with a 0db little splitter to route 1 antenna into 2 GPS receivers. To keep the isolation up I want to use an active splitter instead of a passive one. Randy, For a long time I used a passive splitter made from a swap meet $1 MCL (minicircuits) 1 to 2 GHz splitter / combiner. Isolation of these is good, around 30 dB, and the extra 3 dB loss will not be noticed in the majority of cases. This one had SMAs all round and DC continuity through from the A and B ports to the Common. I blocked one path to DC with a 100 pF SM capacitor. If you need the Rx connected to the blocked path to think it is feeding an antenna a series R and L combination with a 220 Ohm R will fool the Rx in question. I really would not think you will need any gain. For more than two receivers though I would recommend the hp / symmetricom (?) 4 and 8 way active splitters that can be found on eBay. If you did want gain there are a lot of MMICs that will do the job. I've given it away a while back so can't give you any further details, but for two receivers this worked well for me. For my growing collection of gps units here I now need more than two... Dan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Component level 1:2 splitter
Hello Randy, You may find that you have excess gain from the existing LNA/Antenna to the GPS RX. Using a passive splitter, 1/2 to both outputs, will not degrade performance. If you do not have excess gain, a cost effective approach is a ebay splitter by Symmetricom. Last one I got was 30$ Stan, W1LE FN41sr Cape Cod randy warner wrote: Guys, I need to come up with a 0db little splitter to route 1 antenna into 2 GPS receivers. To keep the isolation up I want to use an active splitter instead of a passive one. I suppose I could use a passive splitter followed by two LNA's (one to each receiver), but I would then have to add a lot of attenuation to knock the signal back down. I suppose it would work, but the noise factor sure wouldn't be optimum. Does anyone out there know of a single/dual IC solution to this? Everything I have found LNA wise is in the 10-30 dB range. Note that this will be a board mounted circuit and I don't have to worry about connectors, etc. I'm hoping to find a little solution that I can cover with one of Laird's standard shield cans. Thanks, Randy Warner ___ 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] Component level 1:2 splitter
Hi Randy: Do you know that one of the receivers causes a problem for the other one? It may be that a passive splitter is all you need, like: http://www.prc68.com/I/4GPS.shtml To get more isolation you could pad between the splitter and receivers since most receivers operate over a large dynamic range. If you think you will want to run a number of receivers you might consider a repeater. It consists of a high gain amp (about 30 to 50 dB) followed by a passive antenna mounted on the ceiling pointing down. I found that setting the receivers side by side where they were toughing each other caused problems, but 6 inches of separation was all that was needed for isolation. Have Fun, Brooke Clarke http://www.prc68.com/P/Prod.html Products I make and sell http://www.prc68.com/Alpha.shtml All my web pages listed based on html name http://www.PRC68.com http://www.precisionclock.com http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam randy warner wrote: Guys, I need to come up with a 0db little splitter to route 1 antenna into 2 GPS receivers. To keep the isolation up I want to use an active splitter instead of a passive one. I suppose I could use a passive splitter followed by two LNA's (one to each receiver), but I would then have to add a lot of attenuation to knock the signal back down. I suppose it would work, but the noise factor sure wouldn't be optimum. Does anyone out there know of a single/dual IC solution to this? Everything I have found LNA wise is in the 10-30 dB range. Note that this will be a board mounted circuit and I don't have to worry about connectors, etc. I'm hoping to find a little solution that I can cover with one of Laird's standard shield cans. Thanks, Randy Warner ___ 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] GPS-Attached Equipment Lightning Protection
On Fri, Feb 29, 2008 at 6:50 PM, Tom Van Baak [EMAIL PROTECTED] wrote: I'd be interested in reports on how well these work for GPS antennas, both in terms of lightning protection and in terms of attenuation, tempco, or phase delay. Permanent GPS Stations - Surge and Lightning Protection: Coaxial Cable Protection http://facility.unavco.org/project_support/permanent/equipment/lightning/coax.html and the (dated) report Effects of Lightning Electromagnetic Pulse (LEMP) Protection on GPS Signals http://facility.unavco.org/project_support/permanent/equipment/lightning/lemp_report.html. Some mentioned I.C.E. (Industrial Communication Engineers)'s impulse suppression units, note that their HF and VHF/UHF units are only rated for up to 200MHz and 1000 MHz respectively, which is less than the L1 frequency of 1575.42 MHz. Their TVRO / DBS unit may work. Polyphaser make several different GPS specific models. http://www.iceradioproducts.com/ http://www.polyphaser.com/productdata.aspx?class=gps ___ 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] Rubidium Oscillators
For maximum stability, the rubidium should be run continuous. I lost a lamp in a FRK-L last summer. The unit had been running for 9 years continuous - and I was the second owner. It was used at a LORAN site previous, I am sure they probably ran it continuous, for the same reasons. The failure mode is the lamp glass (inside) gets covered with burnt substance, and loses transparency. Since the unit is looking for less than a one percent drop in light, for resonance, it does not take much, to lose lock. If you do not need high stability, you can run the unit intermittently as required. After power up / lock most rubidiums are in parts 1x10-9, and usually in parts 1x10-10 in thirty minutes. If you run continuously, you should see parts in Xx10-11 to Xx10-12. Brian KD4FM Roy Phillips wrote: good members What are your opinions on the usage of Rubidium Frequency Standards - in the sense - should they be used for short periods of time (until they reach a stable state) as a check only,or is it permissible to run them continuously? In other words, is the lamp (which is the expensive replacement item), deteriorating on a linear scale, and how fast ? I trust that this isn't a stupid question, as it was put to me recently and I was unsure of the answer. I currently feed my Racal 9480 TF Mainframe continuously with the 10 MHz signal from a Ball Efratom Rubidium Standard, assuming that its superior to the OCXO built into the 9480. Or would it be more sensible cost wise, to adjust the OCXO against it on a regular basis? Like many other such matters, probably the answer is obvious - but what do you say ? regards Roy ___ 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] Rubidium Oscillators
On Mon, Mar 10, 2008 at 10:12:46PM -0500, Brian Kirby wrote: For maximum stability, the rubidium should be run continuous. I lost a lamp in a FRK-L last summer. The unit had been running for 9 years continuous - and I was the second owner. It was used at a LORAN site previous, I am sure they probably ran it continuous, for the same reasons. According to various spec docs I have seen, many of the telecom oriented rubidiums (such as the LPRO and FE series) are designed for between 15-20 years lamp life continuously on... so running one that way is not likely to use up available life quickly unless the unit already has lots and lots and lots of hours on it. And they aren't absurdly expensive on Ebay these days - bet a new bulb (if even available) is almost as much as a used but working rb off Ebay. -- Dave Emery N1PRE/AE, [EMAIL PROTECTED] DIE Consulting, Weston, Mass 02493 An empty zombie mind with a forlorn barely readable weatherbeaten 'For Rent' sign still vainly flapping outside on the weed encrusted pole - in celebration of what could have been, but wasn't and is not to be now either. ___ 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.
