Re: [time-nuts] GPS and Rubidium frequency standards and noise question (newbie).
As for the spectrum analyzer, shipping is the killer. I picked up a nice condition HP 8566B for around $USD 900 but it would blow through your budget real quick to ship there. Keep an eye out on eBay for units listed to end on an odd hour and set snipes. Peter On Jun 6, 2012, at 6:53 PM, Chris Wilson wrote: > > 06/06/2012 23:47 > > Just to thank everyone for the warm welcome and splendid advice, I > couldn't have asked for anything more. A great bunch of boffins (in > the nicest possible way ;)) I have just ordered from a well known > auction site's China Town a Thunderbolt kit and will be looking > forward to installing it in my shack when it arrives. It should be a > great starter and give me confidence the readings from various items > of test gear. If you can't trust the test gear, you are a bit stuffed! > > As an aside, and very off topic, I am wanting a decent used spectrum > analyzer. If I lived in the USA they appear to be oozing from the > woodwork, over here in the UK they are harder to find in demonstrably > working order for a decent price. My top budget is £950. I can collect > and I can make snappy decisions. Thanks. > > > > -- > Best Regards, > Chris Wilson. > > > ___ > 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 and Rubidium frequency standards and noise question (newbie).
06/06/2012 23:47 Just to thank everyone for the warm welcome and splendid advice, I couldn't have asked for anything more. A great bunch of boffins (in the nicest possible way ;)) I have just ordered from a well known auction site's China Town a Thunderbolt kit and will be looking forward to installing it in my shack when it arrives. It should be a great starter and give me confidence the readings from various items of test gear. If you can't trust the test gear, you are a bit stuffed! As an aside, and very off topic, I am wanting a decent used spectrum analyzer. If I lived in the USA they appear to be oozing from the woodwork, over here in the UK they are harder to find in demonstrably working order for a decent price. My top budget is £950. I can collect and I can make snappy decisions. Thanks. -- Best Regards, Chris Wilson. ___ 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 and Rubidium frequency standards and noise question (newbie).
TAPR released the TADD-2 in March I believe; I just saw them demo it at Dayton. http://www.tapr.org/kits_tadd-2.html -Chase W4TI ___ 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 and Rubidium frequency standards and noise question (newbie).
Ditto. I daisy chained devices together before I got a 10 Mhz distribution amp. So long as I didn't make any changes to the cabling while making critical measurements it seemed to work okay. Regards Mark Spencer -- On Tue, 5 Jun, 2012 8:28 PM EDT Bob Camp wrote: >Hi > >You should be able to daisy chain a number of devices off of a TBolt. More or >less, you run a BNC cable with a bunch of Tee's on it to distribute the >signal. The end of the cable should get a 50 ohm load. There are better / >fancier / more expensive ways to do it using distribution amplifiers. > >Bob > >On Jun 5, 2012, at 8:20 PM, Chris Wilson wrote: > >> >> >> Hi >> >> For your immediate need, a Thunderbolt sounds like the ideal >> solution. It will give you a very accurate reference to sort out >> your test gear and likely "good enough" phase noise for most of the >> rest of what you want to do. Once you get into the microwave stuff, >> plan your PLL's properly and all will be well there. >> >> Bob >> >> I have thought of something I am unable to find an answer for via the >> normal Googling, etcetera. When I get my GPS locked standard will it >> be able to feed several items of test equipment simultaneously? IE, >> say a sig gen, a frequency counter, and my possible next purchase, a >> Signal Hound USB spectrum analyser? I believe a friend once said he >> uses a GPS reference throughout his shack, but I wasn't sure if he >> meant to multiple devices at the same time, or individually, manually >> swapping cables al the time. Thanks. >> >> >> 06/06/2012 01:16 >> >> >> >> -- >> Best Regards, >> Chris Wilson. >> >> >> ___ >> 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] GPS and Rubidium frequency standards and noise question (newbie).
On Tue, Jun 5, 2012 at 5:20 PM, Chris Wilson wrote: > > > I have thought of something I am unable to find an answer for via the > normal Googling, etcetera. When I get my GPS locked standard will it > be able to feed several items of test equipment simultaneously? IE, > say a sig gen, a frequency counter, and my possible next purchase, a > Signal Hound USB spectrum analyser? I believe a friend once said he > uses a GPS reference throughout his shack, > > It will likely work. Most test equipment is designed not to load down the signal. Certainly it will work for two, likely for three but then you are getting into the area why you might need a distribution amplifier. Some people are using old video amplifiers but the bandwidth of those is marginal. I think you will want the terminate the line (50 ohms) after the last piece of equipment. Tapr's "tadd-1" is an example of a good distribution amp. It is no longer available but you can download and read the manual and see the schematic. You really don't need one but one thing it does provide is isolation of both the signal can grounds. http://www.tapr.org/kits_tadd-1.html -- Chris Albertson Redondo Beach, California ___ 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 and Rubidium frequency standards and noise question (newbie).
Hi You should be able to daisy chain a number of devices off of a TBolt. More or less, you run a BNC cable with a bunch of Tee's on it to distribute the signal. The end of the cable should get a 50 ohm load. There are better / fancier / more expensive ways to do it using distribution amplifiers. Bob On Jun 5, 2012, at 8:20 PM, Chris Wilson wrote: > > >> Hi > >> For your immediate need, a Thunderbolt sounds like the ideal >> solution. It will give you a very accurate reference to sort out >> your test gear and likely "good enough" phase noise for most of the >> rest of what you want to do. Once you get into the microwave stuff, >> plan your PLL's properly and all will be well there. > >> Bob > > I have thought of something I am unable to find an answer for via the > normal Googling, etcetera. When I get my GPS locked standard will it > be able to feed several items of test equipment simultaneously? IE, > say a sig gen, a frequency counter, and my possible next purchase, a > Signal Hound USB spectrum analyser? I believe a friend once said he > uses a GPS reference throughout his shack, but I wasn't sure if he > meant to multiple devices at the same time, or individually, manually > swapping cables al the time. Thanks. > > > 06/06/2012 01:16 > > > > -- > Best Regards, > Chris Wilson. > > > ___ > 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 and Rubidium frequency standards and noise question (newbie).
> Hi > For your immediate need, a Thunderbolt sounds like the ideal > solution. It will give you a very accurate reference to sort out > your test gear and likely "good enough" phase noise for most of the > rest of what you want to do. Once you get into the microwave stuff, > plan your PLL's properly and all will be well there. > Bob I have thought of something I am unable to find an answer for via the normal Googling, etcetera. When I get my GPS locked standard will it be able to feed several items of test equipment simultaneously? IE, say a sig gen, a frequency counter, and my possible next purchase, a Signal Hound USB spectrum analyser? I believe a friend once said he uses a GPS reference throughout his shack, but I wasn't sure if he meant to multiple devices at the same time, or individually, manually swapping cables al the time. Thanks. 06/06/2012 01:16 -- Best Regards, Chris Wilson. ___ 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 and Rubidium frequency standards and noise question (newbie).
On Sun, 03 Jun 2012 18:16:15 -0400, Bob Camp wrote: > Hi > > As long as it shows "rev E" or "rev D" it's likely a later version unit. > The date code on the OCXO is the best indicator, but even that's not > 100%. As long as it's one made after about 2002 you will have a good > one. > Search on Eb..: 10mhz gps I bought 2 from the American seller , he has Item# 170848624524 And they were Rev E , after a month or so i bought some of the "old DS1620 temp sensor chips" Item # 110888667598 , but i think these might be the old type also Item # 140376728803 , in the US. The "old" DS1620's are purely cosmetic (I have been told) , but i like the moving temperature graphs. Then you'd need: A PSU (+/-12v & +5v - Ie. Item# 170609590979) A gps timing antenna (26+ dB or so - Ie. Item# 180518378555) - This type have an N-Connector mounted , the Tbolt uses F-Connector , so get an N-to- F adapter , and some F-connector plugs. Last some good 4-shielded 75ohm sat cable. /Bingo ___ 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 and Rubidium frequency standards and noise question (newbie).
Hi As long as it shows "rev E" or "rev D" it's likely a later version unit. The date code on the OCXO is the best indicator, but even that's not 100%. As long as it's one made after about 2002 you will have a good one. Bob On Jun 3, 2012, at 5:58 PM, Chris Wilson wrote: > > >> Hi > >> For your immediate need, a Thunderbolt sounds like the ideal >> solution. It will give you a very accurate reference to sort out >> your test gear and likely "good enough" phase noise for most of the >> rest of what you want to do. Once you get into the microwave stuff, >> plan your PLL's properly and all will be well there. > >> Bob > > OK, I'll go for a Thunderbolt, is it allowed and acceptable etiquette to > show an Ebay ad to check it's the later type, which I think it is? > > You have all been a great help, thank you very much indeed, I doubt I > will become as obsessive with accuracy as some of you apparently are, > but it's good to know that such a friendly and sharing group of > experts exists in one locale! > > > 03/06/2012 22:50 > > > > -- > Best Regards, > Chris Wilson. > > > ___ > 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 and Rubidium frequency standards and noise question (newbie).
> Hi > For your immediate need, a Thunderbolt sounds like the ideal > solution. It will give you a very accurate reference to sort out > your test gear and likely "good enough" phase noise for most of the > rest of what you want to do. Once you get into the microwave stuff, > plan your PLL's properly and all will be well there. > Bob OK, I'll go for a Thunderbolt, is it allowed and acceptable etiquette to show an Ebay ad to check it's the later type, which I think it is? You have all been a great help, thank you very much indeed, I doubt I will become as obsessive with accuracy as some of you apparently are, but it's good to know that such a friendly and sharing group of experts exists in one locale! 03/06/2012 22:50 -- Best Regards, Chris Wilson. ___ 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 and Rubidium frequency standards and noise question (newbie).
Hi For your immediate need, a Thunderbolt sounds like the ideal solution. It will give you a very accurate reference to sort out your test gear and likely "good enough" phase noise for most of the rest of what you want to do. Once you get into the microwave stuff, plan your PLL's properly and all will be well there. Bob On Jun 3, 2012, at 2:19 PM, Chris Wilson wrote: > > > > > 03/06/2012 19:09 > > Thanks for the great replies! My immediate need is to check some used > test equipment I have bought, a Racal dana 9908 counter and a Marconi > 2019A signal generator. They don't agree with one another! I was going > to get a Thunderbolt unit and PS, but my friend mentioning noise got > me worried. I may have a play with some SDR gear and I know they can > be locked to a standard i you have one. Longer term my aim is to have > a play with microwaves, which is what this friend is into, and maybe > he has a particular issue with noise with sort of multiplication he is > using? The fact that a GPS reference can be always on and locked to a > reference that someone else maintains, if I understand things correctly, > if simplistically, appeals. I am happy to be guided though, and I > suppose I could always get a different type later if the specific need > arose, although I am not made of money ;) > > Thanks! > > > > -- > Best Regards, > Chris Wilson. > > > ___ > 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 and Rubidium frequency standards and noise question (newbie).
On Sun, Jun 3, 2012 at 11:19 AM, Chris Wilson wrote: > > > > > 03/06/2012 19:09 > > ...My immediate need is to check some used > test equipment I have bought, a Racal dana 9908 counter and a Marconi > 2019A signal generator. They don't agree with one another! I was going > to get a Thunderbolt unit and PS, but my friend mentioning noise got > me worried. > > A Thunderbolt is pretty much a turn-key solution for you. Just add an atenna and power supply. On thing is you can both of those to be good. The PS should be a "clean" and the antenna needs to have a full view of the entire sky for best result. Here is some real date on the Thunderbolt. You can decide if it is noisy or not (noisy being a relative term.)http://www.ke5fx.com/tbolt.htm -- Chris Albertson Redondo Beach, California ___ 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 and Rubidium frequency standards and noise question (newbie).
Hello Chris, You are on the right track. I have had the Trimble Thunderbolts (3 each) for about 5 years now. Just to be sure everything compares favorably I use Lady Heather PC software to monitor their performance (de KE5FX website) Stay tuned to this reflector, lotsa interesting discussions. For me, it all started when I needed better than 1 Hz accuracy to monitor the 137 KHz band for local experimental activity. the 10 MHz from the GPS/DO was the external reference to the HP-3336B synthesizer as a RF test signal to calibrate my RX (IC-706MK2 and a IC-703+) and PC soundcard. Spectrum Lab PC software has a provision to calibrate the PC soundcard, for greater accuracy, but you have to have a very accurate signal source. Then there are the FMT-Nuts, frequency measuring contest nuts, who are getting better than 1 milliHz frequency measurement accuracies on intercontinental (US) HF communications !! I was also doing LORAN-C receiving and could achieve Cesium accuracy, at least 2 orders of magnitude greater accuracy than a GPS/DO. But US/Canadian based LORAN went off the air, but it is still available in Europe. I do not know where you are located, so maybe LORAN has potential for you. AUSTRON made a variety of LORAN-C receivers, 2100F, 2100(R), 2000, etc Stanford Research Systems (SRS) also made the FS-700 Because they are useless in the US, pricing on Ebay has dropped. Stan, W1LECape Cod FN41sr On 6/3/2012 2:19 PM, Chris Wilson wrote: 03/06/2012 19:09 Thanks for the great replies! My immediate need is to check some used test equipment I have bought, a Racal dana 9908 counter and a Marconi 2019A signal generator. They don't agree with one another! I was going to get a Thunderbolt unit and PS, but my friend mentioning noise got me worried. I may have a play with some SDR gear and I know they can be locked to a standard i you have one. Longer term my aim is to have a play with microwaves, which is what this friend is into, and maybe he has a particular issue with noise with sort of multiplication he is using? The fact that a GPS reference can be always on and locked to a reference that someone else maintains, if I understand things correctly, if simplistically, appeals. I am happy to be guided though, and I suppose I could always get a different type later if the specific need arose, although I am not made of money ;) Thanks! ___ 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 and Rubidium frequency standards and noise question (newbie).
Sorry for the waste of bandwidth with my prior blank email. Mea Culpa. Chris, I went thru this process several years ago and ended up purchasing the G3RUH GPSDO. For amateur radio usage (vs time nuts usage) it seemed like a good choice to me. I also liked not having to roll the dice on an auction site purchase for a piece of surplus gear. I've since acquired a number of other units that are more time nuts oriented. Be warned acquiring a GPSDO can be the first step in long journey to determine how good your GSPDO actually is. Over the last few years I've spent far more time and money on time nuts pursuits than on amateur radio. Regards Mark Spencer VE7AFZ --- On Sun, 6/3/12, Mark Spencer wrote: > From: Mark Spencer > Subject: Re: [time-nuts] GPS and Rubidium frequency standards and noise > question (newbie). > To: "Chris Wilson" , "Discussion of precise time and > frequency measurement" > Received: Sunday, June 3, 2012, 3:27 PM > > > Sent from my iPod > > On 2012-06-03, at 2:19 PM, Chris Wilson > wrote: > > > > > > > > > > > 03/06/2012 19:09 > > > > Thanks for the great replies! My immediate need is to > check some used > > test equipment I have bought, a Racal dana 9908 counter > and a Marconi > > 2019A signal generator. They don't agree with one > another! I was going > > to get a Thunderbolt unit and PS, but my friend > mentioning noise got > > me worried. I may have a play with some SDR gear and I > know they can > > be locked to a standard i you have one. Longer term my > aim is to have > > a play with microwaves, which is what this friend is > into, and maybe > > he has a particular issue with noise with sort of > multiplication he is > > using? The fact that a GPS reference can be always on > and locked to a > > reference that someone else maintains, if I understand > things correctly, > > if simplistically, appeals. I am happy to be guided > though, and I > > suppose I could always get a different type later if > the specific need > > arose, although I am not made of money ;) > > > > Thanks! > > > > > > > > -- > > Best Regards, > > > Chris Wilson. > > > > > > ___ > > 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] GPS and Rubidium frequency standards and noise question (newbie).
Sent from my iPod On 2012-06-03, at 2:19 PM, Chris Wilson wrote: > > > > > 03/06/2012 19:09 > > Thanks for the great replies! My immediate need is to check some used > test equipment I have bought, a Racal dana 9908 counter and a Marconi > 2019A signal generator. They don't agree with one another! I was going > to get a Thunderbolt unit and PS, but my friend mentioning noise got > me worried. I may have a play with some SDR gear and I know they can > be locked to a standard i you have one. Longer term my aim is to have > a play with microwaves, which is what this friend is into, and maybe > he has a particular issue with noise with sort of multiplication he is > using? The fact that a GPS reference can be always on and locked to a > reference that someone else maintains, if I understand things correctly, > if simplistically, appeals. I am happy to be guided though, and I > suppose I could always get a different type later if the specific need > arose, although I am not made of money ;) > > Thanks! > > > > -- > Best Regards, > Chris Wilson. > > > ___ > 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 and Rubidium frequency standards and noise question (newbie).
03/06/2012 19:09 Thanks for the great replies! My immediate need is to check some used test equipment I have bought, a Racal dana 9908 counter and a Marconi 2019A signal generator. They don't agree with one another! I was going to get a Thunderbolt unit and PS, but my friend mentioning noise got me worried. I may have a play with some SDR gear and I know they can be locked to a standard i you have one. Longer term my aim is to have a play with microwaves, which is what this friend is into, and maybe he has a particular issue with noise with sort of multiplication he is using? The fact that a GPS reference can be always on and locked to a reference that someone else maintains, if I understand things correctly, if simplistically, appeals. I am happy to be guided though, and I suppose I could always get a different type later if the specific need arose, although I am not made of money ;) Thanks! -- Best Regards, Chris Wilson. ___ 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 and Rubidium frequency standards and noise question (newbie).
Hi If you are trying to do microwave work, phase noise is going to be an issue no matter how you do it. A lot of the design effort always goes into a low noise oscillator chain in that sort of gear. For HF gear, phase noise may not be quite as big an issue. A lot of rigs pretty much ignore the phase noise of their reference. If your radios are not already set up to use a 10 MHz reference, you will need to do some frequency conversion to feed them what they want / need. If that's the case, clean up the phase noise in the conversion process. Normally it's as basic as a crystal oscillator locked up with a narrow band PLL. No need for any fancy OCXO or TCXO, just a home made voltage tunable XO. It's not really even a VCXO, since the tune range can be very narrow. Lots of options… Bob On Jun 2, 2012, at 5:57 PM, Chris Wilson wrote: > > > I am looking to get a frequency standard for my amateur radio shack, > initially for verifying test gear readings, but later as a standard > to lock receiver and transmitter oscillators to. I was going to buy > a GPS frequency standard but a friend warned me these may have noise > issues when I come to use it with an oscillator in RX / TX > applications. It's not something I had considered, so what's the > score here please? Should I not buy a GPS standard? Thanks. Any > links to known safe suitable purchase sources from personal > experience welcome, either here or by PM or e-mail. I am in the UK. > > -- > Best regards, > Chris Wilson mailto:ch...@chriswilson.tv > > > ___ > 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 and Rubidium frequency standards and noise question (newbie).
Chris, To answer your question regarding using a Rubidium standard as a frequency reference for your Transverters. GPS really has nothing to do the main requirement regarding Phase Noise and your Transceivers. But the 10MHz oscillator inside the Rubidium standard is the item that will be the Phase Noise problem if you get the wrong Rubidium standard. There are cheap Rubidiums and there are good Rubidium standards to consider. An LPRO-101 is actually a very good Rubidium standard, and exhibits Phase Noise values of -96dBc/Hz @ 10Hz, -138dBc/Hz @ 100Hz, -152dBc/Hz @ 1KHz offsets from carrier. This is what I use for my 10GHz Transverter reference, but I don't lock it to GPS when in the field. LPRO-101's can be gotten pretty reasonably. Locking the LPRO-101 to a GPS will require more support circuitry, and most of the folks on this list can help you with that. Also, Thunderbolt GPS disciplined units are nice, but I do not know the Phase Noise numbers of a typical Thunderbolt unit. Others here probably know the answer to that. The important thing to remember is you don't what to use 10MHz oscillators that have poor Phase Noise performance as it will effect your weak signal capability if you use a poor Phase Noise oscillator. Jerry At 03:05 PM 6/2/2012, you wrote: >If you want a frequency reference. There is nothing better than GPS. In >fact it you bought a Rubidium you would still need the GPS so you could >calibrate its frequency. > >Some GPSes might be noisy but then you can lock a good double oven crystal >oscillator to it and have what they call a "GPS disciplined crystal >oscillator or "GPSDO". > > > >On Sat, Jun 2, 2012 at 2:57 PM, Chris Wilson wrote: > >> >> >> I am looking to get a frequency standard for my amateur radio shack, >> initially for verifying test gear readings, but later as a standard >> to lock receiver and transmitter oscillators to. I was going to buy >> a GPS frequency standard but a friend warned me these may have noise >> issues when I come to use it with an oscillator in RX / TX >> applications. It's not something I had considered, so what's the >> score here please? Should I not buy a GPS standard? Thanks. Any >> links to known safe suitable purchase sources from personal >> experience welcome, either here or by PM or e-mail. I am in the UK. >> >> -- >> Best regards, >> Chris Wilson mailto:ch...@chriswilson.tv >> >> >> ___ >> 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. >> > > > >-- > >Chris Albertson >Redondo Beach, California >___ >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. Jerry Mulchin ___ 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 and Rubidium frequency standards and noise question (newbie).
On 6/2/12 2:57 PM, Chris Wilson wrote: I am looking to get a frequency standard for my amateur radio shack, initially for verifying test gear readings, but later as a standard to lock receiver and transmitter oscillators to. I was going to buy a GPS frequency standard but a friend warned me these may have noise issues when I come to use it with an oscillator in RX / TX applications. It's not something I had considered, so what's the score here please? Should I not buy a GPS standard? Thanks. Any links to known safe suitable purchase sources from personal experience welcome, either here or by PM or e-mail. I am in the UK. What's your need, frequency accuracy wise? What's your phase noise requirement? The first thing to look at would be an ovenized quartz oscillator. They're stable (aging rate is around 1E-10/day.. ) and pretty quiet (-165 dBc at 10kHz out). They run $50-100 on eBay or similar, and are pretty easy.. you hook up a 12 or 15V DC power supply and they put out 10 MHz.. Like an old HP 10811 or a Wenzel Streamline would do you nicely. (BTW, a lot of test equipment has a decent oscillator inside.. so you if you got a suitable counter or signal generator, surplus, that has a good oscillator, then you just use the reference output from the instrument. Ask on this list about candidate instruments) if 1E-10/day isn't good enough... (maybe you're doing microwave hilltopping every 6 months.. 1E-10/day would be 0.01 ppm, so your 10GHz signal would be off by 100 Hz every time you went out) Then, a GPS disciplined quartz oscillator (any of several kinds are available surplus or cobble one together yourself) is probably your best bet. Even without the GPS signal, it will typically be pretty quiet and stable (because basically it's an ovenized XO). HP Z3801As used to be common, Trimble Thunderbolts are more recent, etc. A Rb source (bunches of these on the surplus market recently) is another choice. Just like the GPS, they usually are disciplining a quartz oscillator, so the output spectral purity is really that of the quartz oscillator. Advantage of a Rb is that it works indoors or underground where there is no GPS. And, it's accurate sooner after applying power in most cases. But they DO age, and you need to adjust them (still, pretty good.. aging might be 1E-8 over 20 years. ) The lamp wears out too, so a 25 year old surplus Rb might be near end of life (or might not). google the FS725 for an example of what a current inexpensive Rb reference looks like. Surplus, the internal source can be in the $100 range, but you'll have to cobble up a power supply, and probably modify some connectors. This list has lots of people who can give you advice on this, though. But it gets back to.. how good do you need? ___ 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 and Rubidium frequency standards and noise question (newbie).
If you want a frequency reference. There is nothing better than GPS. In fact it you bought a Rubidium you would still need the GPS so you could calibrate its frequency. Some GPSes might be noisy but then you can lock a good double oven crystal oscillator to it and have what they call a "GPS disciplined crystal oscillator or "GPSDO". On Sat, Jun 2, 2012 at 2:57 PM, Chris Wilson wrote: > > > I am looking to get a frequency standard for my amateur radio shack, > initially for verifying test gear readings, but later as a standard > to lock receiver and transmitter oscillators to. I was going to buy > a GPS frequency standard but a friend warned me these may have noise > issues when I come to use it with an oscillator in RX / TX > applications. It's not something I had considered, so what's the > score here please? Should I not buy a GPS standard? Thanks. Any > links to known safe suitable purchase sources from personal > experience welcome, either here or by PM or e-mail. I am in the UK. > > -- > Best regards, > Chris Wilson mailto:ch...@chriswilson.tv > > > ___ > 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. > -- Chris Albertson Redondo Beach, California ___ 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] GPS and Rubidium frequency standards and noise question (newbie).
I am looking to get a frequency standard for my amateur radio shack, initially for verifying test gear readings, but later as a standard to lock receiver and transmitter oscillators to. I was going to buy a GPS frequency standard but a friend warned me these may have noise issues when I come to use it with an oscillator in RX / TX applications. It's not something I had considered, so what's the score here please? Should I not buy a GPS standard? Thanks. Any links to known safe suitable purchase sources from personal experience welcome, either here or by PM or e-mail. I am in the UK. -- Best regards, Chris Wilson mailto:ch...@chriswilson.tv ___ 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.
