Re: [time-nuts] time-nuts Digest, Vol 102, Issue 89
Hi Magnus, The idea of not having to wonder if I can trust the source, i.e. a GPSDO, is appealing for sure, and one more antenna isn't going to hurt :-) Thanks for your reply. Russ On Wed, Jan 23, 2013 at 1:45 PM, time-nuts-requ...@febo.com wrote: Message: 5 Date: Wed, 23 Jan 2013 20:17:01 +0100 From: Magnus Danielson mag...@rubidium.dyndns.org To: time-nuts@febo.com Subject: Re: [time-nuts] Least costly 10 MHz reference solution Message-ID: 5100372d.30...@rubidium.dyndns.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Russ, Welcome! A rubidium or GPSDO such as Thunderbolt can be found fairly cheaply. If you go for a Thunderbolt, get one with antenna as a kit, mostly because it is a handy way to get started. For better stability you can get a better antenna later, if the need would occur. The rubidium should give you the precision you need straight out of the box, unless it has issues. In order to control if it has issues, having the ability to at least compare to GPS becomes obvious, so you end up wanting that GPSDO anyway. You can get both for reachable money anyway, if you look around long enough. Doing a home-cooked GPSDO is fun naturally, and there is an art in low-budget designs giving fair amount of performance. Cheers, Magnus ___ 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] time-nuts Digest, Vol 102, Issue 89
Hi Bob, That's a good point and not nit picking. While my particular HP 5334A counter (sans 1.3 GHz channel C option) only measures with this kind of resolution at lower frequencies, I will be using the source for my Fluke 6060B (instead of the 5334A's output as I do now) which can produce a 1050 MHz signal, and of course any future test equipment needs. So yeah, I suppose I'd appreciate having a 1 ppb accuracy now that I've thought about it. Thanks. Russ On Wed, Jan 23, 2013 at 1:45 PM, time-nuts-requ...@febo.com wrote: Message: 8 Date: Wed, 23 Jan 2013 14:48:36 -0500 From: Bob Camp li...@rtty.us To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] Least costly 10 MHz reference solution Message-ID: f3cc4b394995429a86320f617f42d...@vectron.com Content-Type: text/plain; charset=US-ASCII Hi Not to pick nits, but 7 decimal places at what input frequency? Seven places is 10 ppb at 10 MHz. If the input was 100 MHz, it would be 1 ppb. The distinction is significant, since it crosses a boundary. At 10 ppb a free running Rb is fine with no adjustments. At 1 ppb, some adjustment might be needed. You might also want a standard that's 5X better than the expected result. That would get you into the 2 to 0.2 ppb range. Lots of fiddly little details... 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] time-nuts Digest, Vol 102, Issue 89
Hi Russ, When testing rubidiums in my lab yesterday, I found that my main counter-pair (a CNT-90 and a SR-620) was way off, it seems like my primary GPSDO (a Thunderbolt) didn't like the situation. Will have to check things. A few rounds more. Also considering that I have a few (more) cesiums to test now. Ah well. So, I will have to check on my GPSDO... luckily I have several :) Cheers, Magnus On 01/23/2013 09:28 PM, Russ Ramirez wrote: Hi Magnus, The idea of not having to wonder if I can trust the source, i.e. a GPSDO, is appealing for sure, and one more antenna isn't going to hurt :-) Thanks for your reply. Russ On Wed, Jan 23, 2013 at 1:45 PM,time-nuts-requ...@febo.com wrote: Message: 5 Date: Wed, 23 Jan 2013 20:17:01 +0100 From: Magnus Danielsonmag...@rubidium.dyndns.org To: time-nuts@febo.com Subject: Re: [time-nuts] Least costly 10 MHz reference solution Message-ID:5100372d.30...@rubidium.dyndns.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Russ, Welcome! A rubidium or GPSDO such as Thunderbolt can be found fairly cheaply. If you go for a Thunderbolt, get one with antenna as a kit, mostly because it is a handy way to get started. For better stability you can get a better antenna later, if the need would occur. The rubidium should give you the precision you need straight out of the box, unless it has issues. In order to control if it has issues, having the ability to at least compare to GPS becomes obvious, so you end up wanting that GPSDO anyway. You can get both for reachable money anyway, if you look around long enough. Doing a home-cooked GPSDO is fun naturally, and there is an art in low-budget designs giving fair amount of performance. Cheers, Magnus ___ 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] time-nuts Digest, Vol 102, Issue 89
Russ, You might want to consider stopping to think about it now. Otherwise, you'll wind up with a Cesium Standard to check the GPSDO, a collection of OCXO's and Rb's to see which is the best, not to mention all the test equipment needed to carry out those measurements, and, perhaps, a MASER to check the CS. Having done what you are contemplating, I vote for the GPSDO and a TBolt is a great choice. I would recommend a linear power source rather than a 'switching' power supply. Otherwise, get a switching power supply with higher voltages than needed and use some linear regulators downstream to generate the +12, -12, and +5 needed for the TBolt. Good luck. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Russ Ramirez Sent: Wednesday, January 23, 2013 2:24 PM To: time-nuts@febo.com Subject: Re: [time-nuts] time-nuts Digest, Vol 102, Issue 89 Hi Bob, That's a good point and not nit picking. While my particular HP 5334A counter (sans 1.3 GHz channel C option) only measures with this kind of resolution at lower frequencies, I will be using the source for my Fluke 6060B (instead of the 5334A's output as I do now) which can produce a 1050 MHz signal, and of course any future test equipment needs. So yeah, I suppose I'd appreciate having a 1 ppb accuracy now that I've thought about it. Thanks. Russ On Wed, Jan 23, 2013 at 1:45 PM, time-nuts-requ...@febo.com wrote: Message: 8 Date: Wed, 23 Jan 2013 14:48:36 -0500 From: Bob Camp li...@rtty.us To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] Least costly 10 MHz reference solution Message-ID: f3cc4b394995429a86320f617f42d...@vectron.com Content-Type: text/plain; charset=US-ASCII Hi Not to pick nits, but 7 decimal places at what input frequency? Seven places is 10 ppb at 10 MHz. If the input was 100 MHz, it would be 1 ppb. The distinction is significant, since it crosses a boundary. At 10 ppb a free running Rb is fine with no adjustments. At 1 ppb, some adjustment might be needed. You might also want a standard that's 5X better than the expected result. That would get you into the 2 to 0.2 ppb range. Lots of fiddly little details... 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] time-nuts Digest, Vol 102, Issue 89
Don't forget the ion fountain to check the H Maser :-) Sent from my iPhone On Jan 23, 2013, at 5:35 PM, J. L. Trantham jlt...@att.net wrote: Russ, You might want to consider stopping to think about it now. Otherwise, you'll wind up with a Cesium Standard to check the GPSDO, a collection of OCXO's and Rb's to see which is the best, not to mention all the test equipment needed to carry out those measurements, and, perhaps, a MASER to check the CS. Having done what you are contemplating, I vote for the GPSDO and a TBolt is a great choice. I would recommend a linear power source rather than a 'switching' power supply. Otherwise, get a switching power supply with higher voltages than needed and use some linear regulators downstream to generate the +12, -12, and +5 needed for the TBolt. Good luck. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Russ Ramirez Sent: Wednesday, January 23, 2013 2:24 PM To: time-nuts@febo.com Subject: Re: [time-nuts] time-nuts Digest, Vol 102, Issue 89 Hi Bob, That's a good point and not nit picking. While my particular HP 5334A counter (sans 1.3 GHz channel C option) only measures with this kind of resolution at lower frequencies, I will be using the source for my Fluke 6060B (instead of the 5334A's output as I do now) which can produce a 1050 MHz signal, and of course any future test equipment needs. So yeah, I suppose I'd appreciate having a 1 ppb accuracy now that I've thought about it. Thanks. Russ On Wed, Jan 23, 2013 at 1:45 PM, time-nuts-requ...@febo.com wrote: Message: 8 Date: Wed, 23 Jan 2013 14:48:36 -0500 From: Bob Camp li...@rtty.us To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: Re: [time-nuts] Least costly 10 MHz reference solution Message-ID: f3cc4b394995429a86320f617f42d...@vectron.com Content-Type: text/plain; charset=US-ASCII Hi Not to pick nits, but 7 decimal places at what input frequency? Seven places is 10 ppb at 10 MHz. If the input was 100 MHz, it would be 1 ppb. The distinction is significant, since it crosses a boundary. At 10 ppb a free running Rb is fine with no adjustments. At 1 ppb, some adjustment might be needed. You might also want a standard that's 5X better than the expected result. That would get you into the 2 to 0.2 ppb range. Lots of fiddly little details... 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. ___ 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] time-nuts Digest, Vol 102, Issue 89
On 01/23/2013 11:35 PM, J. L. Trantham wrote: Russ, You might want to consider stopping to think about it now. Otherwise, you'll wind up with a Cesium Standard to check the GPSDO, a collection of OCXO's and Rb's to see which is the best, not to mention all the test equipment needed to carry out those measurements, and, perhaps, a MASER to check the CS. I've come to the level that besides having things properly rigged, the lack of H-masers is annoying :) Cheers, Magnus ___ 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.
