[time-nuts] Re: Frequency Standard - Where Can I Get One.
Hi Bob, thx a lot. Now I can keep it on my list and try to get it on the second Hand market in a couple of years 😉. Its a bit too much for my hobby budget. I am only interested in the Audio frequences below 50mhz range, so GHz is not important at the Moment for me Kind regards Norman Gesendet von Yahoo Mail auf Android Am So., Nov. 21, 2021 at 1:05 schrieb Bob kb8tq: Hi Rb standards have a finite life. Just how long that is depends a lot on how good a job the heatsink on them did as well as the run time. They do die of fairly normal random stuff as well. Like just about everything designed in the last 30 years, schematics and field repair manuals simply don’t exist. What to do: Start looking for shorted caps. If voltages are ok then move on to things like the frequency of the local oscillator. You can get surplus Rb’s built into functioning devices. Typical price seems to be in the $500 and up range. The advantage is that at least it worked when it shipped. How long it will continue to work …. who knows …. Bob > On Nov 20, 2021, at 5:42 PM, Robert Garnett wrote: > > Hi, > > > About five years ago I purchased a rubidium standard on eBay. It was an > Efratom. Sadly although The oscillator was working but it wouldn't lock. I > was comparing it to a HP Z38001A which I use as the frequency standard in my > lab. > > I tried to fix it, but I couldn't find the correct schematic so I abandoned > the project. > > I would like some advice on where I could get a working one and how much I > should pay. > > -- > Best Regards Rob Garnett > Toongabbie Vctoria > 0351 489484 > 0417 995 247 > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an > email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Frequency Standard - Where Can I Get One.
That reminds me; Used to have a TWTT link via satellite watching a Caesium at an English Gov site. Was puzzled to watch the relative freq cycle day and night until we learned the UKGOV site room at nit and day different temperature control settings. 1 UK Cs vs. our 3 Cs and ulta pure flywheel. Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y (Reformed USNSG CTM1) les...@veenstras.com 452 Stable Ln Keyser WV 26726 USA GPS: 39.336826 N 78.982287 W (Google) GPS: 39.33682 N 78.9823741 W (GPSDO) Telephones: Home:+1-304-289-6057 US cell  +1-304-790-9192 Jamaica cell: +1-876-456-8898 -Original Message- From: Lux, Jim [mailto:j...@luxfamily.com] Sent: Monday, November 22, 2021 10:56 PM To: time-nuts@lists.febo.com Subject: [time-nuts] Re: Frequency Standard - Where Can I Get One. On 11/22/21 7:51 PM, Bill Notfaded wrote: > There's no substitute for a few good rubidiums. OCXO and Rb are > different. It's really hard to beat a really good GNSS diciplined Rb! > Extremely good holdover. We're timenuts after all right? Where's the fun > if you don't try them all? There isn't any silver bullet or perfect > solution but I've found with some good measurement and comparisons you too > can be in the search of better and better stability. Half the fun is > finding a better OCXO or finding a really stable Rb. Testing them all > against each other is part of the journey. Letting timelab run all night > every night. Flipping back and forth between graphs. For me it's a hobby > but I've gotten many many hours of great happiness from it. The first time > I got into 10 ^ -13 how can you explain what that's like? The huge digits > on an SR620 you can read from across the room. I guess it's different for > each of us but it's something we all share. > > Bill When you get to where you can see the air conditioning or heat in the room cycling on and off, with TCXO and OXCOs.. "What's that bump at 1000 seconds?" ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Frequency Standard - Where Can I Get One.
On 11/22/21 7:51 PM, Bill Notfaded wrote: There's no substitute for a few good rubidiums. OCXO and Rb are different. It's really hard to beat a really good GNSS diciplined Rb! Extremely good holdover. We're timenuts after all right? Where's the fun if you don't try them all? There isn't any silver bullet or perfect solution but I've found with some good measurement and comparisons you too can be in the search of better and better stability. Half the fun is finding a better OCXO or finding a really stable Rb. Testing them all against each other is part of the journey. Letting timelab run all night every night. Flipping back and forth between graphs. For me it's a hobby but I've gotten many many hours of great happiness from it. The first time I got into 10 ^ -13 how can you explain what that's like? The huge digits on an SR620 you can read from across the room. I guess it's different for each of us but it's something we all share. Bill When you get to where you can see the air conditioning or heat in the room cycling on and off, with TCXO and OXCOs.. "What's that bump at 1000 seconds?" ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Frequency Standard - Where Can I Get One.
There's no substitute for a few good rubidiums. OCXO and Rb are different. It's really hard to beat a really good GNSS diciplined Rb! Extremely good holdover. We're timenuts after all right? Where's the fun if you don't try them all? There isn't any silver bullet or perfect solution but I've found with some good measurement and comparisons you too can be in the search of better and better stability. Half the fun is finding a better OCXO or finding a really stable Rb. Testing them all against each other is part of the journey. Letting timelab run all night every night. Flipping back and forth between graphs. For me it's a hobby but I've gotten many many hours of great happiness from it. The first time I got into 10 ^ -13 how can you explain what that's like? The huge digits on an SR620 you can read from across the room. I guess it's different for each of us but it's something we all share. Bill On Sun, Nov 21, 2021, 1:58 PM Magnus Danielson via time-nuts < time-nuts@lists.febo.com> wrote: > Hi, > > So, on that note. I am surprised that I have not seen popular telecom > rubidiums being reverse-engineered. For instance, the LPRO-101 should > have been reverse-engineered a long time. Some of the circuitry is known > from patents, but those do not build up a complete schematic. I've > considered to do the job, but apparently I have not been able to sit > down and do that particular job either. > > I think the LRPO-101 should not be too much of a challenge. Beyond the > schematic some documentation of the other functions, hints and tips, > etc. that is related should be written up so one approach something > similar to a service manual. > > With enough people contributing, I think it should not be too hard to > collect things. We should be able to provide useful hints and tricks, > such as suitable replacement components etc. > > Cheers, > Magnus > > Den 2021-11-21 kl. 19:45, skrev Bob kb8tq: > > Hi > > > > Well, if I could keep a 5065 running without repairs for more than a > couple years > > I might be more willing to agree with you. What makes the 5065 different > is that you > > have schematics and can do repairs. When the telecom gizmos die, there’s > not much > > to fall back on. They were designed to run a finite amount of time and > then go to the > > scrap heap. > > > > Bob > > > >> On Nov 21, 2021, at 12:03 PM, Skip Withrow > wrote: > >> > >> Hello Time-Nuts, > >> > >> No offense Bob, but I would like to take issue with your statement 'Rb > >> standards have a finite life'. > >> > >> There are time-nuts on this list of every skill and knowledge level > >> and I would like to keep the information as correct as possible. My > >> feeling is this is not a true statement. > >> > >> There is nothing inherent in the design of a rubidium frequency > >> standard that limits its life (unlike cesium). However, there are > >> manufacturing choices that can possibly limit time before failure. > >> > >> First example, of course, is the HP 5065. There are many of us that > >> have units that have been running continuously for close to 50 years. > >> HP made choices in their bulb design that ensures that it runs for a > >> very long time. > >> > >> An opposite example would be the Tracor rubidiums. The lamps in these > >> units were either horribly underfilled, or the glass was very reactive > >> with Rb and almost all suffered from rather early lamp failures. > >> > >> Then, there is the huge mass of telecom rubidiums. As you stated, > >> keeping the base plate at a reasonable temperature goes a LONG way to > >> extended life. Excessive temperature obviously leads to higher > >> component (and sometimes lamp) failure. > >> > >> There are also units that just did not have enough design margin in > >> certain areas. The SRS PRS-10 is one of these where I have seen > >> things go up in smoke in the lamp area. BTW, the HP 5065 can have > >> some issues in this area as well. > >> > >> I'm obviously a big fan of rubidium frequency standards. My advice to > >> newer time-nuts is that you can't go wrong owning one (better long > >> term stability than OCXO, lots less cost and longer life than cesium). > >> > >> I'll get off the soap box now. Thanks for the bandwidth. > >> > >> Skip Withrow > >> ___ > >> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > send an email to time-nuts-le...@lists.febo.com > >> To unsubscribe, go to and follow the instructions there. > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > send an email to time-nuts-le...@lists.febo.com > > To unsubscribe, go to and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. _
[time-nuts] Re: Frequency Standard - Where Can I Get One.
Hi, So, on that note. I am surprised that I have not seen popular telecom rubidiums being reverse-engineered. For instance, the LPRO-101 should have been reverse-engineered a long time. Some of the circuitry is known from patents, but those do not build up a complete schematic. I've considered to do the job, but apparently I have not been able to sit down and do that particular job either. I think the LRPO-101 should not be too much of a challenge. Beyond the schematic some documentation of the other functions, hints and tips, etc. that is related should be written up so one approach something similar to a service manual. With enough people contributing, I think it should not be too hard to collect things. We should be able to provide useful hints and tricks, such as suitable replacement components etc. Cheers, Magnus Den 2021-11-21 kl. 19:45, skrev Bob kb8tq: Hi Well, if I could keep a 5065 running without repairs for more than a couple years I might be more willing to agree with you. What makes the 5065 different is that you have schematics and can do repairs. When the telecom gizmos die, there’s not much to fall back on. They were designed to run a finite amount of time and then go to the scrap heap. Bob On Nov 21, 2021, at 12:03 PM, Skip Withrow wrote: Hello Time-Nuts, No offense Bob, but I would like to take issue with your statement 'Rb standards have a finite life'. There are time-nuts on this list of every skill and knowledge level and I would like to keep the information as correct as possible. My feeling is this is not a true statement. There is nothing inherent in the design of a rubidium frequency standard that limits its life (unlike cesium). However, there are manufacturing choices that can possibly limit time before failure. First example, of course, is the HP 5065. There are many of us that have units that have been running continuously for close to 50 years. HP made choices in their bulb design that ensures that it runs for a very long time. An opposite example would be the Tracor rubidiums. The lamps in these units were either horribly underfilled, or the glass was very reactive with Rb and almost all suffered from rather early lamp failures. Then, there is the huge mass of telecom rubidiums. As you stated, keeping the base plate at a reasonable temperature goes a LONG way to extended life. Excessive temperature obviously leads to higher component (and sometimes lamp) failure. There are also units that just did not have enough design margin in certain areas. The SRS PRS-10 is one of these where I have seen things go up in smoke in the lamp area. BTW, the HP 5065 can have some issues in this area as well. I'm obviously a big fan of rubidium frequency standards. My advice to newer time-nuts is that you can't go wrong owning one (better long term stability than OCXO, lots less cost and longer life than cesium). I'll get off the soap box now. Thanks for the bandwidth. Skip Withrow ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Frequency Standard - Where Can I Get One.
Hi Well, if I could keep a 5065 running without repairs for more than a couple years I might be more willing to agree with you. What makes the 5065 different is that you have schematics and can do repairs. When the telecom gizmos die, there’s not much to fall back on. They were designed to run a finite amount of time and then go to the scrap heap. Bob > On Nov 21, 2021, at 12:03 PM, Skip Withrow wrote: > > Hello Time-Nuts, > > No offense Bob, but I would like to take issue with your statement 'Rb > standards have a finite life'. > > There are time-nuts on this list of every skill and knowledge level > and I would like to keep the information as correct as possible. My > feeling is this is not a true statement. > > There is nothing inherent in the design of a rubidium frequency > standard that limits its life (unlike cesium). However, there are > manufacturing choices that can possibly limit time before failure. > > First example, of course, is the HP 5065. There are many of us that > have units that have been running continuously for close to 50 years. > HP made choices in their bulb design that ensures that it runs for a > very long time. > > An opposite example would be the Tracor rubidiums. The lamps in these > units were either horribly underfilled, or the glass was very reactive > with Rb and almost all suffered from rather early lamp failures. > > Then, there is the huge mass of telecom rubidiums. As you stated, > keeping the base plate at a reasonable temperature goes a LONG way to > extended life. Excessive temperature obviously leads to higher > component (and sometimes lamp) failure. > > There are also units that just did not have enough design margin in > certain areas. The SRS PRS-10 is one of these where I have seen > things go up in smoke in the lamp area. BTW, the HP 5065 can have > some issues in this area as well. > > I'm obviously a big fan of rubidium frequency standards. My advice to > newer time-nuts is that you can't go wrong owning one (better long > term stability than OCXO, lots less cost and longer life than cesium). > > I'll get off the soap box now. Thanks for the bandwidth. > > Skip Withrow > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an > email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Frequency Standard - Where Can I Get One.
Hello Time-Nuts, No offense Bob, but I would like to take issue with your statement 'Rb standards have a finite life'. There are time-nuts on this list of every skill and knowledge level and I would like to keep the information as correct as possible. My feeling is this is not a true statement. There is nothing inherent in the design of a rubidium frequency standard that limits its life (unlike cesium). However, there are manufacturing choices that can possibly limit time before failure. First example, of course, is the HP 5065. There are many of us that have units that have been running continuously for close to 50 years. HP made choices in their bulb design that ensures that it runs for a very long time. An opposite example would be the Tracor rubidiums. The lamps in these units were either horribly underfilled, or the glass was very reactive with Rb and almost all suffered from rather early lamp failures. Then, there is the huge mass of telecom rubidiums. As you stated, keeping the base plate at a reasonable temperature goes a LONG way to extended life. Excessive temperature obviously leads to higher component (and sometimes lamp) failure. There are also units that just did not have enough design margin in certain areas. The SRS PRS-10 is one of these where I have seen things go up in smoke in the lamp area. BTW, the HP 5065 can have some issues in this area as well. I'm obviously a big fan of rubidium frequency standards. My advice to newer time-nuts is that you can't go wrong owning one (better long term stability than OCXO, lots less cost and longer life than cesium). I'll get off the soap box now. Thanks for the bandwidth. Skip Withrow ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Frequency Standard - Where Can I Get One.
Hi Rb standards have a finite life. Just how long that is depends a lot on how good a job the heatsink on them did as well as the run time. They do die of fairly normal random stuff as well. Like just about everything designed in the last 30 years, schematics and field repair manuals simply don’t exist. What to do: Start looking for shorted caps. If voltages are ok then move on to things like the frequency of the local oscillator. You can get surplus Rb’s built into functioning devices. Typical price seems to be in the $500 and up range. The advantage is that at least it worked when it shipped. How long it will continue to work …. who knows …. Bob > On Nov 20, 2021, at 5:42 PM, Robert Garnett wrote: > > Hi, > > > About five years ago I purchased a rubidium standard on eBay. It was an > Efratom. Sadly although The oscillator was working but it wouldn't lock. I > was comparing it to a HP Z38001A which I use as the frequency standard in my > lab. > > I tried to fix it, but I couldn't find the correct schematic so I abandoned > the project. > > I would like some advice on where I could get a working one and how much I > should pay. > > -- > Best Regards Rob Garnett > Toongabbie Vctoria > 0351 489484 > 0417 995 247 > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an > email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
