List, Allan variation is good. Allan variation can reveal valuable information. But when it comes to do it I feel like Lou Costello in Who’s On First? I’ve been an electronics technician all my working life. Math beyond A squared plus B squared equals C squared is beyond my abilities. I have quite a bit of test equipment and several computers. What I need is a Dummy’s Guide to Making Allan Variation Measurements. I’ve looked at Wikipedia and I am as lost as when I started. Could someone walk me through the process step by step and also tell me what test equipment is required? TIA Perrier

> I’ve looked at Wikipedia and I am as lost as when I started. > > Could someone walk me through the process step by step and also > tell me what test equipment is required? > Besides the pointers at www.leapsecond.com , I've collected a few links at http://www.ke5fx.com/stability.htm that may be helpful. The first .PDF link on that page is my presentation from the Microwave Update conference a few weeks ago. It was meant as an introductory "Stability Measurement for Radio Nuts" talk, discussing the state of the commercial art in light of what's available to hobbyists. The NIST links under "General timing and noise metrology", in particular this one ( http://tf.nist.gov/general/pdf/2220.pdf ) are excellent. If you have an HP 5370A/B counter and a GPIB interface you can do a lot of good measurement work. With the appropriate software you can make conventional strip-chart style plots of frequency and phase, as well as ADEV and similar plots. Unless you are a software nut you probably do not want to homebrew the necessary code to do this. Most people don't use the same program for acquisition and plotting; a script or batch file does the job of reading the data from the counter and spooling it to a text file, while a program like Stable32 or Ulrich Bangert's (search on df6jb plotter) renders the graphics. My own app (TimeLab) is an exception, in that it attempts to do a good job at both data acquisition and rendering. It's still under heavy construction. Right now I'm rewriting all of the acquisition routines to support, among other things, the use of more than one GPIB counter at once. Given that you have an HP 5370 available, if you wanted a walkthrough, you could try something along these lines: 1) Get an NI or Prologix GPIB adapter, install per manufacturer's guidelines. 2) Download the current TimeLab beta. You have two options here: http://www.ke5fx.com/timelab/setup.exe -- Graphically ugly but better tested http://www.ke5fx.com/timelab/setup_temp.exe -- Nicer looking, but more likely to have bugs, and some features have yet to be ported over to the new codebase. Use this one for the instructions below. 3) Decide whether you want your HP 5370A/B to run in talk-only mode or addressable mode and set its DIP switch accordingly. The software will work either way since it doesn't actually try to control the counter, but for a 5370 I'd use addressable mode unless you have a reason not to. 4) Set up a basic frequency measurement to begin with. Feed a 10 MHz signal or whatever into the STOP jack, and hit FREQ and 1s. 5) In TimeLab, select Acquire->Acquire from HP 5370A/B, and then select the NI interface or the Prologix interface's COM port from the list. Hit the "Monitor" button and you should start seeing the counter's frequency readings scroll by. If not, find out why before going any further. 6) Hit "Start Measurement." After a few readings have come in, you should see your ADEV plot start to take shape. 7) Hit the 'f' key to switch to a frequency-difference chart, or the 'p' key for a phase-difference chart. The 'y' key will toggle the Y-axis between easy-to-read round numbers and full display range. You can get somewhat cleaner measurements from the 5370 if you use time-interval mode rather than frequency mode, but time-interval measurements require a 1-pps or similar source and some additional setup effort. -- john, KE5FX > -----Original Message----- > From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On > Behalf Of Perry Sandeen > Sent: Saturday, November 13, 2010 9:41 PM > To: time-nuts-request@febo.com > Subject: [time-nuts] How does one actually do Allan variation graphs? > > > List, > > Allan variation is good. Allan variation can reveal valuable information. > > But when it comes to do it I feel like Lou Costello in Who’s On First? > > I’ve been an electronics technician all my working life. Math > beyond A squared plus B squared equals C squared is beyond my abilities. > > I have quite a bit of test equipment and several computers. > > What I need is a Dummy’s Guide to Making Allan Variation Measurements. > > I’ve looked at Wikipedia and I am as lost as when I started. > > Could someone walk me through the process step by step and also > tell me what test equipment is required? > > TIA > > Perrier >

On 11/14/2010 09:41 AM, John Miles wrote: > >> I’ve looked at Wikipedia and I am as lost as when I started. >> >> Could someone walk me through the process step by step and also >> tell me what test equipment is required? >> > > Besides the pointers at www.leapsecond.com , I've collected a few links at http://www.ke5fx.com/stability.htm that may be helpful. > > The first .PDF link on that page is my presentation from the Microwave Update conference a few weeks ago. It was meant as an introductory "Stability Measurement for Radio Nuts" talk, discussing the state of the commercial art in light of what's available to hobbyists. > > The NIST links under "General timing and noise metrology", in particular this one ( http://tf.nist.gov/general/pdf/2220.pdf ) are excellent. > > If you have an HP 5370A/B counter and a GPIB interface you can do a lot of good measurement work. With the appropriate software you can make conventional strip-chart style plots of frequency and phase, as well as ADEV and similar plots. Unless you are a software nut you probably do not want to homebrew the necessary code to do this. Most people don't use the same program for acquisition and plotting; a script or batch file does the job of reading the data from the counter and spooling it to a text file, while a program like Stable32 or Ulrich Bangert's (search on df6jb plotter) renders the graphics. > > My own app (TimeLab) is an exception, in that it attempts to do a good job at both data acquisition and rendering. It's still under heavy construction. Right now I'm rewriting all of the acquisition routines to support, among other things, the use of more than one GPIB counter at once. > > Given that you have an HP 5370 available, if you wanted a walkthrough, you could try something along these lines: > > 1) Get an NI or Prologix GPIB adapter, install per manufacturer's guidelines. > > 2) Download the current TimeLab beta. You have two options here: > http://www.ke5fx.com/timelab/setup.exe -- Graphically ugly but better tested > http://www.ke5fx.com/timelab/setup_temp.exe -- Nicer looking, but more likely to have bugs, and some features have yet to be ported over to the new codebase. Use this one for the instructions below. > > 3) Decide whether you want your HP 5370A/B to run in talk-only mode or addressable mode and set its DIP switch accordingly. The software will work either way since it doesn't actually try to control the counter, but for a 5370 I'd use addressable mode unless you have a reason not to. > > 4) Set up a basic frequency measurement to begin with. Feed a 10 MHz signal or whatever into the STOP jack, and hit FREQ and 1s. > > 5) In TimeLab, select Acquire->Acquire from HP 5370A/B, and then select the NI interface or the Prologix interface's COM port from the list. Hit the "Monitor" button and you should start seeing the counter's frequency readings scroll by. If not, find out why before going any further. > > 6) Hit "Start Measurement." After a few readings have come in, you should see your ADEV plot start to take shape. > > 7) Hit the 'f' key to switch to a frequency-difference chart, or the 'p' key for a phase-difference chart. The 'y' key will toggle the Y-axis between easy-to-read round numbers and full display range. > > You can get somewhat cleaner measurements from the 5370 if you use time-interval mode rather than frequency mode, but time-interval measurements require a 1-pps or similar source and some additional setup effort. 0) Essentially whatever source you have (crystal, Rubidium, Cesium, GPSDO) unless you haven't done it before, turn it on well in advance. I prefer days over hours. Locked crystals such as Rubidium, Cesium and GPSDOs will cancel the last part of the oscillator drift but depending on details performance may be more or less compromised by this drift. I think this is one of the practical details one should not miss. I for one thinks that using a trigger signal such as the PPS or more preferably a higher frequency trigger is worthwhile, as you get a more stable rate of read-outs. Also, it gives a larger amount of raw data, allowing for the increased degrees of freedom and quicker convergence of estimator(s). Do use TimeLab, I think it is a great way to get going. It's also fun to see the curve converge as more data comes in... Cheers, Magnus

Gentlemen, What is a reasonable price for a 5370A? Local guy here is trying to hawk one to me. Not cosmetically perfect but fully operational. Yes, I know someone is going to say, "I got one for 50 bucks." But really, what is a fair price? Thanks, Bill On Sun, Nov 14, 2010 at 10:48 AM, Magnus Danielson < magnus@rubidium.dyndns.org> wrote: > On 11/14/2010 09:41 AM, John Miles wrote: > >> >> I’ve looked at Wikipedia and I am as lost as when I started. >>> >>> Could someone walk me through the process step by step and also >>> tell me what test equipment is required? >>> >>> >> Besides the pointers at www.leapsecond.com , I've collected a few links >> at http://www.ke5fx.com/stability.htm that may be helpful. >> >> The first .PDF link on that page is my presentation from the Microwave >> Update conference a few weeks ago. It was meant as an introductory >> "Stability Measurement for Radio Nuts" talk, discussing the state of the >> commercial art in light of what's available to hobbyists. >> >> The NIST links under "General timing and noise metrology", in particular >> this one ( http://tf.nist.gov/general/pdf/2220.pdf ) are excellent. >> >> If you have an HP 5370A/B counter and a GPIB interface you can do a lot of >> good measurement work. With the appropriate software you can make >> conventional strip-chart style plots of frequency and phase, as well as ADEV >> and similar plots. Unless you are a software nut you probably do not want >> to homebrew the necessary code to do this. Most people don't use the same >> program for acquisition and plotting; a script or batch file does the job of >> reading the data from the counter and spooling it to a text file, while a >> program like Stable32 or Ulrich Bangert's (search on df6jb plotter) renders >> the graphics. >> >> My own app (TimeLab) is an exception, in that it attempts to do a good job >> at both data acquisition and rendering. It's still under heavy >> construction. Right now I'm rewriting all of the acquisition routines to >> support, among other things, the use of more than one GPIB counter at once. >> >> Given that you have an HP 5370 available, if you wanted a walkthrough, you >> could try something along these lines: >> >> 1) Get an NI or Prologix GPIB adapter, install per manufacturer's >> guidelines. >> >> 2) Download the current TimeLab beta. You have two options here: >> http://www.ke5fx.com/timelab/setup.exe -- Graphically ugly but >> better tested >> http://www.ke5fx.com/timelab/setup_temp.exe -- Nicer looking, but >> more likely to have bugs, and some features have yet to be ported over to >> the new codebase. Use this one for the instructions below. >> >> 3) Decide whether you want your HP 5370A/B to run in talk-only mode or >> addressable mode and set its DIP switch accordingly. The software will work >> either way since it doesn't actually try to control the counter, but for a >> 5370 I'd use addressable mode unless you have a reason not to. >> >> 4) Set up a basic frequency measurement to begin with. Feed a 10 MHz >> signal or whatever into the STOP jack, and hit FREQ and 1s. >> >> 5) In TimeLab, select Acquire->Acquire from HP 5370A/B, and then select >> the NI interface or the Prologix interface's COM port from the list. Hit >> the "Monitor" button and you should start seeing the counter's frequency >> readings scroll by. If not, find out why before going any further. >> >> 6) Hit "Start Measurement." After a few readings have come in, you should >> see your ADEV plot start to take shape. >> >> 7) Hit the 'f' key to switch to a frequency-difference chart, or the 'p' >> key for a phase-difference chart. The 'y' key will toggle the Y-axis >> between easy-to-read round numbers and full display range. >> >> You can get somewhat cleaner measurements from the 5370 if you use >> time-interval mode rather than frequency mode, but time-interval >> measurements require a 1-pps or similar source and some additional setup >> effort. >> > > 0) Essentially whatever source you have (crystal, Rubidium, Cesium, GPSDO) > unless you haven't done it before, turn it on well in advance. I prefer days > over hours. Locked crystals such as Rubidium, Cesium and GPSDOs will cancel > the last part of the oscillator drift but depending on details performance > may be more or less compromised by this drift. I think this is one of the > practical details one should not miss. > > I for one thinks that using a trigger signal such as the PPS or more > preferably a higher frequency trigger is worthwhile, as you get a more > stable rate of read-outs. Also, it gives a larger amount of raw data, > allowing for the increased degrees of freedom and quicker convergence of > estimator(s). > > Do use TimeLab, I think it is a great way to get going. It's also fun to > see the curve converge as more data comes in... > > 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. >

Hi Assuming: 1) All the knobs and switches are intact and working 2) All the led's in the display work 3) All the alarm and indicator LED's work 4) The input amps are good 5) All the connectors are intact 6) The OCXO is good / on frequency 7) It passes the diags 8) Jitter is down below 100 ps ( should be below 40) 9) You can check all this out before purchace. Let the beast warm up for at least an hour before you check it. Something in the $180 to $260 range is probably fair depending on cosmetics. You might start out at $150 in order to compromise at $200. I certainly would not pay over $300. I know the list sounds a bit long, but I've seen 5370's with problems in each of those areas. Pretty much anything damaged / non-functional would knock a pretty good chunk off the price. Bob On Nov 14, 2010, at 11:29 AM, William H. Fite wrote: > Gentlemen, > > What is a reasonable price for a 5370A? Local guy here is trying to hawk > one to me. Not cosmetically perfect but fully operational. > > Yes, I know someone is going to say, "I got one for 50 bucks." But really, > what is a fair price? > > Thanks, > > Bill > > > > > On Sun, Nov 14, 2010 at 10:48 AM, Magnus Danielson < > magnus@rubidium.dyndns.org> wrote: > >> On 11/14/2010 09:41 AM, John Miles wrote: >> >>> >>> I’ve looked at Wikipedia and I am as lost as when I started. >>>> >>>> Could someone walk me through the process step by step and also >>>> tell me what test equipment is required? >>>> >>>> >>> Besides the pointers at www.leapsecond.com , I've collected a few links >>> at http://www.ke5fx.com/stability.htm that may be helpful. >>> >>> The first .PDF link on that page is my presentation from the Microwave >>> Update conference a few weeks ago. It was meant as an introductory >>> "Stability Measurement for Radio Nuts" talk, discussing the state of the >>> commercial art in light of what's available to hobbyists. >>> >>> The NIST links under "General timing and noise metrology", in particular >>> this one ( http://tf.nist.gov/general/pdf/2220.pdf ) are excellent. >>> >>> If you have an HP 5370A/B counter and a GPIB interface you can do a lot of >>> good measurement work. With the appropriate software you can make >>> conventional strip-chart style plots of frequency and phase, as well as ADEV >>> and similar plots. Unless you are a software nut you probably do not want >>> to homebrew the necessary code to do this. Most people don't use the same >>> program for acquisition and plotting; a script or batch file does the job of >>> reading the data from the counter and spooling it to a text file, while a >>> program like Stable32 or Ulrich Bangert's (search on df6jb plotter) renders >>> the graphics. >>> >>> My own app (TimeLab) is an exception, in that it attempts to do a good job >>> at both data acquisition and rendering. It's still under heavy >>> construction. Right now I'm rewriting all of the acquisition routines to >>> support, among other things, the use of more than one GPIB counter at once. >>> >>> Given that you have an HP 5370 available, if you wanted a walkthrough, you >>> could try something along these lines: >>> >>> 1) Get an NI or Prologix GPIB adapter, install per manufacturer's >>> guidelines. >>> >>> 2) Download the current TimeLab beta. You have two options here: >>> http://www.ke5fx.com/timelab/setup.exe -- Graphically ugly but >>> better tested >>> http://www.ke5fx.com/timelab/setup_temp.exe -- Nicer looking, but >>> more likely to have bugs, and some features have yet to be ported over to >>> the new codebase. Use this one for the instructions below. >>> >>> 3) Decide whether you want your HP 5370A/B to run in talk-only mode or >>> addressable mode and set its DIP switch accordingly. The software will work >>> either way since it doesn't actually try to control the counter, but for a >>> 5370 I'd use addressable mode unless you have a reason not to. >>> >>> 4) Set up a basic frequency measurement to begin with. Feed a 10 MHz >>> signal or whatever into the STOP jack, and hit FREQ and 1s. >>> >>> 5) In TimeLab, select Acquire->Acquire from HP 5370A/B, and then select >>> the NI interface or the Prologix interface's COM port from the list. Hit >>> the "Monitor" button and you should start seeing the counter's frequency >>> readings scroll by. If not, find out why before going any further. >>> >>> 6) Hit "Start Measurement." After a few readings have come in, you should >>> see your ADEV plot start to take shape. >>> >>> 7) Hit the 'f' key to switch to a frequency-difference chart, or the 'p' >>> key for a phase-difference chart. The 'y' key will toggle the Y-axis >>> between easy-to-read round numbers and full display range. >>> >>> You can get somewhat cleaner measurements from the 5370 if you use >>> time-interval mode rather than frequency mode, but time-interval >>> measurements require a 1-pps or similar source and some additional setup >>> effort. >>> >> >> 0) Essentially whatever source you have (crystal, Rubidium, Cesium, GPSDO) >> unless you haven't done it before, turn it on well in advance. I prefer days >> over hours. Locked crystals such as Rubidium, Cesium and GPSDOs will cancel >> the last part of the oscillator drift but depending on details performance >> may be more or less compromised by this drift. I think this is one of the >> practical details one should not miss. >> >> I for one thinks that using a trigger signal such as the PPS or more >> preferably a higher frequency trigger is worthwhile, as you get a more >> stable rate of read-outs. Also, it gives a larger amount of raw data, >> allowing for the increased degrees of freedom and quicker convergence of >> estimator(s). >> >> Do use TimeLab, I think it is a great way to get going. It's also fun to >> see the curve converge as more data comes in... >> >> 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.

Thanks, Bob He's asking $400 but I can tell by the look in his eye that he'll take substantially less. He's a lousy poker player, too... I asked him to turn it on about 0900 this morning and I'm going over in an hour or so to check it out. Thanks again, Bill On Sun, Nov 14, 2010 at 11:44 AM, Bob Camp <lists@rtty.us> wrote: > Hi > > Assuming: > > 1) All the knobs and switches are intact and working > 2) All the led's in the display work > 3) All the alarm and indicator LED's work > 4) The input amps are good > 5) All the connectors are intact > 6) The OCXO is good / on frequency > 7) It passes the diags > 8) Jitter is down below 100 ps ( should be below 40) > 9) You can check all this out before purchace. Let the beast warm up for at > least an hour before you check it. > > Something in the $180 to $260 range is probably fair depending on > cosmetics. You might start out at $150 in order to compromise at $200. I > certainly would not pay over $300. I know the list sounds a bit long, but > I've seen 5370's with problems in each of those areas. Pretty much anything > damaged / non-functional would knock a pretty good chunk off the price. > > Bob > > > On Nov 14, 2010, at 11:29 AM, William H. Fite wrote: > > > Gentlemen, > > > > What is a reasonable price for a 5370A? Local guy here is trying to hawk > > one to me. Not cosmetically perfect but fully operational. > > > > Yes, I know someone is going to say, "I got one for 50 bucks." But > really, > > what is a fair price? > > > > Thanks, > > > > Bill > > > > > > > > > > On Sun, Nov 14, 2010 at 10:48 AM, Magnus Danielson < > > magnus@rubidium.dyndns.org> wrote: > > > >> On 11/14/2010 09:41 AM, John Miles wrote: > >> > >>> > >>> I’ve looked at Wikipedia and I am as lost as when I started. > >>>> > >>>> Could someone walk me through the process step by step and also > >>>> tell me what test equipment is required? > >>>> > >>>> > >>> Besides the pointers at www.leapsecond.com , I've collected a few > links > >>> at http://www.ke5fx.com/stability.htm that may be helpful. > >>> > >>> The first .PDF link on that page is my presentation from the Microwave > >>> Update conference a few weeks ago. It was meant as an introductory > >>> "Stability Measurement for Radio Nuts" talk, discussing the state of > the > >>> commercial art in light of what's available to hobbyists. > >>> > >>> The NIST links under "General timing and noise metrology", in > particular > >>> this one ( http://tf.nist.gov/general/pdf/2220.pdf ) are excellent. > >>> > >>> If you have an HP 5370A/B counter and a GPIB interface you can do a lot > of > >>> good measurement work. With the appropriate software you can make > >>> conventional strip-chart style plots of frequency and phase, as well as > ADEV > >>> and similar plots. Unless you are a software nut you probably do not > want > >>> to homebrew the necessary code to do this. Most people don't use the > same > >>> program for acquisition and plotting; a script or batch file does the > job of > >>> reading the data from the counter and spooling it to a text file, while > a > >>> program like Stable32 or Ulrich Bangert's (search on df6jb plotter) > renders > >>> the graphics. > >>> > >>> My own app (TimeLab) is an exception, in that it attempts to do a good > job > >>> at both data acquisition and rendering. It's still under heavy > >>> construction. Right now I'm rewriting all of the acquisition routines > to > >>> support, among other things, the use of more than one GPIB counter at > once. > >>> > >>> Given that you have an HP 5370 available, if you wanted a walkthrough, > you > >>> could try something along these lines: > >>> > >>> 1) Get an NI or Prologix GPIB adapter, install per manufacturer's > >>> guidelines. > >>> > >>> 2) Download the current TimeLab beta. You have two options here: > >>> http://www.ke5fx.com/timelab/setup.exe -- Graphically ugly but > >>> better tested > >>> http://www.ke5fx.com/timelab/setup_temp.exe -- Nicer looking, > but > >>> more likely to have bugs, and some features have yet to be ported over > to > >>> the new codebase. Use this one for the instructions below. > >>> > >>> 3) Decide whether you want your HP 5370A/B to run in talk-only mode or > >>> addressable mode and set its DIP switch accordingly. The software will > work > >>> either way since it doesn't actually try to control the counter, but > for a > >>> 5370 I'd use addressable mode unless you have a reason not to. > >>> > >>> 4) Set up a basic frequency measurement to begin with. Feed a 10 MHz > >>> signal or whatever into the STOP jack, and hit FREQ and 1s. > >>> > >>> 5) In TimeLab, select Acquire->Acquire from HP 5370A/B, and then select > >>> the NI interface or the Prologix interface's COM port from the list. > Hit > >>> the "Monitor" button and you should start seeing the counter's > frequency > >>> readings scroll by. If not, find out why before going any further. > >>> > >>> 6) Hit "Start Measurement." After a few readings have come in, you > should > >>> see your ADEV plot start to take shape. > >>> > >>> 7) Hit the 'f' key to switch to a frequency-difference chart, or the > 'p' > >>> key for a phase-difference chart. The 'y' key will toggle the Y-axis > >>> between easy-to-read round numbers and full display range. > >>> > >>> You can get somewhat cleaner measurements from the 5370 if you use > >>> time-interval mode rather than frequency mode, but time-interval > >>> measurements require a 1-pps or similar source and some additional > setup > >>> effort. > >>> > >> > >> 0) Essentially whatever source you have (crystal, Rubidium, Cesium, > GPSDO) > >> unless you haven't done it before, turn it on well in advance. I prefer > days > >> over hours. Locked crystals such as Rubidium, Cesium and GPSDOs will > cancel > >> the last part of the oscillator drift but depending on details > performance > >> may be more or less compromised by this drift. I think this is one of > the > >> practical details one should not miss. > >> > >> I for one thinks that using a trigger signal such as the PPS or more > >> preferably a higher frequency trigger is worthwhile, as you get a more > >> stable rate of read-outs. Also, it gives a larger amount of raw data, > >> allowing for the increased degrees of freedom and quicker convergence of > >> estimator(s). > >> > >> Do use TimeLab, I think it is a great way to get going. It's also fun to > >> see the curve converge as more data comes in... > >> > >> 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. > > > _______________________________________________ > 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. >

Hi Like a lot of stuff, the going price for these has dropped. They get less and less respect every day ... One thing that may be specific to me - I do not consider a 5370A to be any more or less valuable than a 5370B. They both do pretty much the same thing. The 5370B might have fewer hours on it, it might not. On average 5370A prices seem to run slightly higher than 5370B prices. Why is a mystery to me. Bob On Nov 14, 2010, at 11:57 AM, William H. Fite wrote: > Thanks, Bob > > He's asking $400 but I can tell by the look in his eye that he'll take > substantially less. > > He's a lousy poker player, too... > > I asked him to turn it on about 0900 this morning and I'm going over in an > hour or so to check it out. > > Thanks again, > > Bill > > > > > On Sun, Nov 14, 2010 at 11:44 AM, Bob Camp <lists@rtty.us> wrote: > >> Hi >> >> Assuming: >> >> 1) All the knobs and switches are intact and working >> 2) All the led's in the display work >> 3) All the alarm and indicator LED's work >> 4) The input amps are good >> 5) All the connectors are intact >> 6) The OCXO is good / on frequency >> 7) It passes the diags >> 8) Jitter is down below 100 ps ( should be below 40) >> 9) You can check all this out before purchace. Let the beast warm up for at >> least an hour before you check it. >> >> Something in the $180 to $260 range is probably fair depending on >> cosmetics. You might start out at $150 in order to compromise at $200. I >> certainly would not pay over $300. I know the list sounds a bit long, but >> I've seen 5370's with problems in each of those areas. Pretty much anything >> damaged / non-functional would knock a pretty good chunk off the price. >> >> Bob >> >> >> On Nov 14, 2010, at 11:29 AM, William H. Fite wrote: >> >>> Gentlemen, >>> >>> What is a reasonable price for a 5370A? Local guy here is trying to hawk >>> one to me. Not cosmetically perfect but fully operational. >>> >>> Yes, I know someone is going to say, "I got one for 50 bucks." But >> really, >>> what is a fair price? >>> >>> Thanks, >>> >>> Bill >>> >>> >>> >>> >>> On Sun, Nov 14, 2010 at 10:48 AM, Magnus Danielson < >>> magnus@rubidium.dyndns.org> wrote: >>> >>>> On 11/14/2010 09:41 AM, John Miles wrote: >>>> >>>>> >>>>> I’ve looked at Wikipedia and I am as lost as when I started. >>>>>> >>>>>> Could someone walk me through the process step by step and also >>>>>> tell me what test equipment is required? >>>>>> >>>>>> >>>>> Besides the pointers at www.leapsecond.com , I've collected a few >> links >>>>> at http://www.ke5fx.com/stability.htm that may be helpful. >>>>> >>>>> The first .PDF link on that page is my presentation from the Microwave >>>>> Update conference a few weeks ago. It was meant as an introductory >>>>> "Stability Measurement for Radio Nuts" talk, discussing the state of >> the >>>>> commercial art in light of what's available to hobbyists. >>>>> >>>>> The NIST links under "General timing and noise metrology", in >> particular >>>>> this one ( http://tf.nist.gov/general/pdf/2220.pdf ) are excellent. >>>>> >>>>> If you have an HP 5370A/B counter and a GPIB interface you can do a lot >> of >>>>> good measurement work. With the appropriate software you can make >>>>> conventional strip-chart style plots of frequency and phase, as well as >> ADEV >>>>> and similar plots. Unless you are a software nut you probably do not >> want >>>>> to homebrew the necessary code to do this. Most people don't use the >> same >>>>> program for acquisition and plotting; a script or batch file does the >> job of >>>>> reading the data from the counter and spooling it to a text file, while >> a >>>>> program like Stable32 or Ulrich Bangert's (search on df6jb plotter) >> renders >>>>> the graphics. >>>>> >>>>> My own app (TimeLab) is an exception, in that it attempts to do a good >> job >>>>> at both data acquisition and rendering. It's still under heavy >>>>> construction. Right now I'm rewriting all of the acquisition routines >> to >>>>> support, among other things, the use of more than one GPIB counter at >> once. >>>>> >>>>> Given that you have an HP 5370 available, if you wanted a walkthrough, >> you >>>>> could try something along these lines: >>>>> >>>>> 1) Get an NI or Prologix GPIB adapter, install per manufacturer's >>>>> guidelines. >>>>> >>>>> 2) Download the current TimeLab beta. You have two options here: >>>>> http://www.ke5fx.com/timelab/setup.exe -- Graphically ugly but >>>>> better tested >>>>> http://www.ke5fx.com/timelab/setup_temp.exe -- Nicer looking, >> but >>>>> more likely to have bugs, and some features have yet to be ported over >> to >>>>> the new codebase. Use this one for the instructions below. >>>>> >>>>> 3) Decide whether you want your HP 5370A/B to run in talk-only mode or >>>>> addressable mode and set its DIP switch accordingly. The software will >> work >>>>> either way since it doesn't actually try to control the counter, but >> for a >>>>> 5370 I'd use addressable mode unless you have a reason not to. >>>>> >>>>> 4) Set up a basic frequency measurement to begin with. Feed a 10 MHz >>>>> signal or whatever into the STOP jack, and hit FREQ and 1s. >>>>> >>>>> 5) In TimeLab, select Acquire->Acquire from HP 5370A/B, and then select >>>>> the NI interface or the Prologix interface's COM port from the list. >> Hit >>>>> the "Monitor" button and you should start seeing the counter's >> frequency >>>>> readings scroll by. If not, find out why before going any further. >>>>> >>>>> 6) Hit "Start Measurement." After a few readings have come in, you >> should >>>>> see your ADEV plot start to take shape. >>>>> >>>>> 7) Hit the 'f' key to switch to a frequency-difference chart, or the >> 'p' >>>>> key for a phase-difference chart. The 'y' key will toggle the Y-axis >>>>> between easy-to-read round numbers and full display range. >>>>> >>>>> You can get somewhat cleaner measurements from the 5370 if you use >>>>> time-interval mode rather than frequency mode, but time-interval >>>>> measurements require a 1-pps or similar source and some additional >> setup >>>>> effort. >>>>> >>>> >>>> 0) Essentially whatever source you have (crystal, Rubidium, Cesium, >> GPSDO) >>>> unless you haven't done it before, turn it on well in advance. I prefer >> days >>>> over hours. Locked crystals such as Rubidium, Cesium and GPSDOs will >> cancel >>>> the last part of the oscillator drift but depending on details >> performance >>>> may be more or less compromised by this drift. I think this is one of >> the >>>> practical details one should not miss. >>>> >>>> I for one thinks that using a trigger signal such as the PPS or more >>>> preferably a higher frequency trigger is worthwhile, as you get a more >>>> stable rate of read-outs. Also, it gives a larger amount of raw data, >>>> allowing for the increased degrees of freedom and quicker convergence of >>>> estimator(s). >>>> >>>> Do use TimeLab, I think it is a great way to get going. It's also fun to >>>> see the curve converge as more data comes in... >>>> >>>> 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. >> >> >> _______________________________________________ >> 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.

Really good advice on what to checkout. 5370s are the devil to fix if somethings wrong such as jitter. Good luck. Paul On Sun, Nov 14, 2010 at 12:40 PM, Bob Camp <lists@rtty.us> wrote: > Hi > > Like a lot of stuff, the going price for these has dropped. They get less > and less respect every day ... > > One thing that may be specific to me - I do not consider a 5370A to be any > more or less valuable than a 5370B. They both do pretty much the same thing. > The 5370B might have fewer hours on it, it might not. On average 5370A > prices seem to run slightly higher than 5370B prices. Why is a mystery to > me. > > Bob > > > On Nov 14, 2010, at 11:57 AM, William H. Fite wrote: > > > Thanks, Bob > > > > He's asking $400 but I can tell by the look in his eye that he'll take > > substantially less. > > > > He's a lousy poker player, too... > > > > I asked him to turn it on about 0900 this morning and I'm going over in > an > > hour or so to check it out. > > > > Thanks again, > > > > Bill > > > > > > > > > > On Sun, Nov 14, 2010 at 11:44 AM, Bob Camp <lists@rtty.us> wrote: > > > >> Hi > >> > >> Assuming: > >> > >> 1) All the knobs and switches are intact and working > >> 2) All the led's in the display work > >> 3) All the alarm and indicator LED's work > >> 4) The input amps are good > >> 5) All the connectors are intact > >> 6) The OCXO is good / on frequency > >> 7) It passes the diags > >> 8) Jitter is down below 100 ps ( should be below 40) > >> 9) You can check all this out before purchace. Let the beast warm up for > at > >> least an hour before you check it. > >> > >> Something in the $180 to $260 range is probably fair depending on > >> cosmetics. You might start out at $150 in order to compromise at $200. I > >> certainly would not pay over $300. I know the list sounds a bit long, > but > >> I've seen 5370's with problems in each of those areas. Pretty much > anything > >> damaged / non-functional would knock a pretty good chunk off the price. > >> > >> Bob > >> > >> > >> On Nov 14, 2010, at 11:29 AM, William H. Fite wrote: > >> > >>> Gentlemen, > >>> > >>> What is a reasonable price for a 5370A? Local guy here is trying to > hawk > >>> one to me. Not cosmetically perfect but fully operational. > >>> > >>> Yes, I know someone is going to say, "I got one for 50 bucks." But > >> really, > >>> what is a fair price? > >>> > >>> Thanks, > >>> > >>> Bill > >>> > >>> > >>> > >>> > >>> On Sun, Nov 14, 2010 at 10:48 AM, Magnus Danielson < > >>> magnus@rubidium.dyndns.org> wrote: > >>> > >>>> On 11/14/2010 09:41 AM, John Miles wrote: > >>>> > >>>>> > >>>>> I’ve looked at Wikipedia and I am as lost as when I started. > >>>>>> > >>>>>> Could someone walk me through the process step by step and also > >>>>>> tell me what test equipment is required? > >>>>>> > >>>>>> > >>>>> Besides the pointers at www.leapsecond.com , I've collected a few > >> links > >>>>> at http://www.ke5fx.com/stability.htm that may be helpful. > >>>>> > >>>>> The first .PDF link on that page is my presentation from the > Microwave > >>>>> Update conference a few weeks ago. It was meant as an introductory > >>>>> "Stability Measurement for Radio Nuts" talk, discussing the state of > >> the > >>>>> commercial art in light of what's available to hobbyists. > >>>>> > >>>>> The NIST links under "General timing and noise metrology", in > >> particular > >>>>> this one ( http://tf.nist.gov/general/pdf/2220.pdf ) are excellent. > >>>>> > >>>>> If you have an HP 5370A/B counter and a GPIB interface you can do a > lot > >> of > >>>>> good measurement work. With the appropriate software you can make > >>>>> conventional strip-chart style plots of frequency and phase, as well > as > >> ADEV > >>>>> and similar plots. Unless you are a software nut you probably do not > >> want > >>>>> to homebrew the necessary code to do this. Most people don't use the > >> same > >>>>> program for acquisition and plotting; a script or batch file does the > >> job of > >>>>> reading the data from the counter and spooling it to a text file, > while > >> a > >>>>> program like Stable32 or Ulrich Bangert's (search on df6jb plotter) > >> renders > >>>>> the graphics. > >>>>> > >>>>> My own app (TimeLab) is an exception, in that it attempts to do a > good > >> job > >>>>> at both data acquisition and rendering. It's still under heavy > >>>>> construction. Right now I'm rewriting all of the acquisition > routines > >> to > >>>>> support, among other things, the use of more than one GPIB counter at > >> once. > >>>>> > >>>>> Given that you have an HP 5370 available, if you wanted a > walkthrough, > >> you > >>>>> could try something along these lines: > >>>>> > >>>>> 1) Get an NI or Prologix GPIB adapter, install per manufacturer's > >>>>> guidelines. > >>>>> > >>>>> 2) Download the current TimeLab beta. You have two options here: > >>>>> http://www.ke5fx.com/timelab/setup.exe -- Graphically ugly but > >>>>> better tested > >>>>> http://www.ke5fx.com/timelab/setup_temp.exe -- Nicer looking, > >> but > >>>>> more likely to have bugs, and some features have yet to be ported > over > >> to > >>>>> the new codebase. Use this one for the instructions below. > >>>>> > >>>>> 3) Decide whether you want your HP 5370A/B to run in talk-only mode > or > >>>>> addressable mode and set its DIP switch accordingly. The software > will > >> work > >>>>> either way since it doesn't actually try to control the counter, but > >> for a > >>>>> 5370 I'd use addressable mode unless you have a reason not to. > >>>>> > >>>>> 4) Set up a basic frequency measurement to begin with. Feed a 10 MHz > >>>>> signal or whatever into the STOP jack, and hit FREQ and 1s. > >>>>> > >>>>> 5) In TimeLab, select Acquire->Acquire from HP 5370A/B, and then > select > >>>>> the NI interface or the Prologix interface's COM port from the list. > >> Hit > >>>>> the "Monitor" button and you should start seeing the counter's > >> frequency > >>>>> readings scroll by. If not, find out why before going any further. > >>>>> > >>>>> 6) Hit "Start Measurement." After a few readings have come in, you > >> should > >>>>> see your ADEV plot start to take shape. > >>>>> > >>>>> 7) Hit the 'f' key to switch to a frequency-difference chart, or the > >> 'p' > >>>>> key for a phase-difference chart. The 'y' key will toggle the Y-axis > >>>>> between easy-to-read round numbers and full display range. > >>>>> > >>>>> You can get somewhat cleaner measurements from the 5370 if you use > >>>>> time-interval mode rather than frequency mode, but time-interval > >>>>> measurements require a 1-pps or similar source and some additional > >> setup > >>>>> effort. > >>>>> > >>>> > >>>> 0) Essentially whatever source you have (crystal, Rubidium, Cesium, > >> GPSDO) > >>>> unless you haven't done it before, turn it on well in advance. I > prefer > >> days > >>>> over hours. Locked crystals such as Rubidium, Cesium and GPSDOs will > >> cancel > >>>> the last part of the oscillator drift but depending on details > >> performance > >>>> may be more or less compromised by this drift. I think this is one of > >> the > >>>> practical details one should not miss. > >>>> > >>>> I for one thinks that using a trigger signal such as the PPS or more > >>>> preferably a higher frequency trigger is worthwhile, as you get a more > >>>> stable rate of read-outs. Also, it gives a larger amount of raw data, > >>>> allowing for the increased degrees of freedom and quicker convergence > of > >>>> estimator(s). > >>>> > >>>> Do use TimeLab, I think it is a great way to get going. It's also fun > to > >>>> see the curve converge as more data comes in... > >>>> > >>>> 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. > >> > >> > >> _______________________________________________ > >> 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. >

Bob's checklist is a good one, all right. It is important to get a solid working example because they are quite challenging to troubleshoot and calibrate. The only problem with the 5370A as far as I'm aware is the reduced reliability caused by the larger number of socketed ROM chips. It seems that many, if not most, 5370s were used with external 10 MHz references. If you're patient, you can wait for one to show up on eBay with a display that is blank except for one bright LED. Buy it cheap, and flip the external-reference switch back to internal-reference mode when you get it. Easy "fix!" -- john, KE5FX > -----Original Message----- > From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On > Behalf Of paul swed > Sent: Sunday, November 14, 2010 8:01 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] How does one actually do Allan variation > graphs? > > > Really good advice on what to checkout. > 5370s are the devil to fix if somethings wrong such as jitter. > Good luck. > Paul > > On Sun, Nov 14, 2010 at 12:40 PM, Bob Camp <lists@rtty.us> wrote: > > > Hi > > > > Like a lot of stuff, the going price for these has dropped. > They get less > > and less respect every day ... > > > > One thing that may be specific to me - I do not consider a > 5370A to be any > > more or less valuable than a 5370B. They both do pretty much > the same thing. > > The 5370B might have fewer hours on it, it might not. On average 5370A > > prices seem to run slightly higher than 5370B prices. Why is a > mystery to > > me. > > > > Bob > > > > > > On Nov 14, 2010, at 11:57 AM, William H. Fite wrote: > > > > > Thanks, Bob > > > > > > He's asking $400 but I can tell by the look in his eye that he'll take > > > substantially less. > > > > > > He's a lousy poker player, too... > > > > > > I asked him to turn it on about 0900 this morning and I'm > going over in > > an > > > hour or so to check it out. > > > > > > Thanks again, > > > > > > Bill > > > > > > > > > > > > > > > On Sun, Nov 14, 2010 at 11:44 AM, Bob Camp <lists@rtty.us> wrote: > > > > > >> Hi > > >> > > >> Assuming: > > >> > > >> 1) All the knobs and switches are intact and working > > >> 2) All the led's in the display work > > >> 3) All the alarm and indicator LED's work > > >> 4) The input amps are good > > >> 5) All the connectors are intact > > >> 6) The OCXO is good / on frequency > > >> 7) It passes the diags > > >> 8) Jitter is down below 100 ps ( should be below 40) > > >> 9) You can check all this out before purchace. Let the beast > warm up for > > at > > >> least an hour before you check it. > > >> > > >> Something in the $180 to $260 range is probably fair depending on > > >> cosmetics. You might start out at $150 in order to > compromise at $200. I > > >> certainly would not pay over $300. I know the list sounds a bit long, > > but > > >> I've seen 5370's with problems in each of those areas. Pretty much > > anything > > >> damaged / non-functional would knock a pretty good chunk off > the price. > > >> > > >> Bob > > >> > > >> > > >> On Nov 14, 2010, at 11:29 AM, William H. Fite wrote: > > >> > > >>> Gentlemen, > > >>> > > >>> What is a reasonable price for a 5370A? Local guy here is trying to > > hawk > > >>> one to me. Not cosmetically perfect but fully operational. > > >>> > > >>> Yes, I know someone is going to say, "I got one for 50 bucks." But > > >> really, > > >>> what is a fair price? > > >>> > > >>> Thanks, > > >>> > > >>> Bill > > >>> > > >>> > > >>> > > >>> > > >>> On Sun, Nov 14, 2010 at 10:48 AM, Magnus Danielson < > > >>> magnus@rubidium.dyndns.org> wrote: > > >>> > > >>>> On 11/14/2010 09:41 AM, John Miles wrote: > > >>>> > > >>>>> > > >>>>> I’ve looked at Wikipedia and I am as lost as when I started. > > >>>>>> > > >>>>>> Could someone walk me through the process step by step and also > > >>>>>> tell me what test equipment is required? > > >>>>>> > > >>>>>> > > >>>>> Besides the pointers at www.leapsecond.com , I've collected a few > > >> links > > >>>>> at http://www.ke5fx.com/stability.htm that may be helpful. > > >>>>> > > >>>>> The first .PDF link on that page is my presentation from the > > Microwave > > >>>>> Update conference a few weeks ago. It was meant as an > introductory > > >>>>> "Stability Measurement for Radio Nuts" talk, discussing > the state of > > >> the > > >>>>> commercial art in light of what's available to hobbyists. > > >>>>> > > >>>>> The NIST links under "General timing and noise metrology", in > > >> particular > > >>>>> this one ( http://tf.nist.gov/general/pdf/2220.pdf ) are > excellent. > > >>>>> > > >>>>> If you have an HP 5370A/B counter and a GPIB interface > you can do a > > lot > > >> of > > >>>>> good measurement work. With the appropriate software you can make > > >>>>> conventional strip-chart style plots of frequency and > phase, as well > > as > > >> ADEV > > >>>>> and similar plots. Unless you are a software nut you > probably do not > > >> want > > >>>>> to homebrew the necessary code to do this. Most people > don't use the > > >> same > > >>>>> program for acquisition and plotting; a script or batch > file does the > > >> job of > > >>>>> reading the data from the counter and spooling it to a text file, > > while > > >> a > > >>>>> program like Stable32 or Ulrich Bangert's (search on > df6jb plotter) > > >> renders > > >>>>> the graphics. > > >>>>> > > >>>>> My own app (TimeLab) is an exception, in that it attempts to do a > > good > > >> job > > >>>>> at both data acquisition and rendering. It's still under heavy > > >>>>> construction. Right now I'm rewriting all of the acquisition > > routines > > >> to > > >>>>> support, among other things, the use of more than one > GPIB counter at > > >> once. > > >>>>> > > >>>>> Given that you have an HP 5370 available, if you wanted a > > walkthrough, > > >> you > > >>>>> could try something along these lines: > > >>>>> > > >>>>> 1) Get an NI or Prologix GPIB adapter, install per manufacturer's > > >>>>> guidelines. > > >>>>> > > >>>>> 2) Download the current TimeLab beta. You have two options here: > > >>>>> http://www.ke5fx.com/timelab/setup.exe -- Graphically ugly but > > >>>>> better tested > > >>>>> http://www.ke5fx.com/timelab/setup_temp.exe -- Nicer looking, > > >> but > > >>>>> more likely to have bugs, and some features have yet to be ported > > over > > >> to > > >>>>> the new codebase. Use this one for the instructions below. > > >>>>> > > >>>>> 3) Decide whether you want your HP 5370A/B to run in > talk-only mode > > or > > >>>>> addressable mode and set its DIP switch accordingly. The software > > will > > >> work > > >>>>> either way since it doesn't actually try to control the > counter, but > > >> for a > > >>>>> 5370 I'd use addressable mode unless you have a reason not to. > > >>>>> > > >>>>> 4) Set up a basic frequency measurement to begin with. > Feed a 10 MHz > > >>>>> signal or whatever into the STOP jack, and hit FREQ and 1s. > > >>>>> > > >>>>> 5) In TimeLab, select Acquire->Acquire from HP 5370A/B, and then > > select > > >>>>> the NI interface or the Prologix interface's COM port > from the list. > > >> Hit > > >>>>> the "Monitor" button and you should start seeing the counter's > > >> frequency > > >>>>> readings scroll by. If not, find out why before going > any further. > > >>>>> > > >>>>> 6) Hit "Start Measurement." After a few readings have > come in, you > > >> should > > >>>>> see your ADEV plot start to take shape. > > >>>>> > > >>>>> 7) Hit the 'f' key to switch to a frequency-difference > chart, or the > > >> 'p' > > >>>>> key for a phase-difference chart. The 'y' key will > toggle the Y-axis > > >>>>> between easy-to-read round numbers and full display range. > > >>>>> > > >>>>> You can get somewhat cleaner measurements from the 5370 if you use > > >>>>> time-interval mode rather than frequency mode, but time-interval > > >>>>> measurements require a 1-pps or similar source and some additional > > >> setup > > >>>>> effort. > > >>>>> > > >>>> > > >>>> 0) Essentially whatever source you have (crystal, Rubidium, Cesium, > > >> GPSDO) > > >>>> unless you haven't done it before, turn it on well in advance. I > > prefer > > >> days > > >>>> over hours. Locked crystals such as Rubidium, Cesium and > GPSDOs will > > >> cancel > > >>>> the last part of the oscillator drift but depending on details > > >> performance > > >>>> may be more or less compromised by this drift. I think > this is one of > > >> the > > >>>> practical details one should not miss. > > >>>> > > >>>> I for one thinks that using a trigger signal such as the > PPS or more > > >>>> preferably a higher frequency trigger is worthwhile, as > you get a more > > >>>> stable rate of read-outs. Also, it gives a larger amount > of raw data, > > >>>> allowing for the increased degrees of freedom and quicker > convergence > > of > > >>>> estimator(s). > > >>>> > > >>>> Do use TimeLab, I think it is a great way to get going. > It's also fun > > to > > >>>> see the curve converge as more data comes in... > > >>>> > > >>>> 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. > > >> > > >> > > >> _______________________________________________ > > >> time-nuts mailing list -- time-nuts@febo.com > > >> To unsubscribe, go to > > >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > >> and follow the instructions there. > > >> > > > _______________________________________________ > > > time-nuts mailing list -- time-nuts@febo.com > > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > and follow the instructions there. > > > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. >

Hi The only reason the check list is any good is the - gee if I'd checked that I would not have bought this one syndrome ... ------------ The same socketed ROMs on the A that have issues while they are "live" are easier to replace if / when they go bad. ------- Many of these counters (any model) spent their life on an external standard. Having an OCXO that's a ppm or two off is not unusual. What you want to watch out for is the one that's 30 or 40 ppm off. Bob On Nov 14, 2010, at 11:15 PM, John Miles wrote: > Bob's checklist is a good one, all right. It is important to get a solid > working example because they are quite challenging to troubleshoot and > calibrate. > > The only problem with the 5370A as far as I'm aware is the reduced > reliability caused by the larger number of socketed ROM chips. > > It seems that many, if not most, 5370s were used with external 10 MHz > references. If you're patient, you can wait for one to show up on eBay with > a display that is blank except for one bright LED. Buy it cheap, and flip > the external-reference switch back to internal-reference mode when you get > it. Easy "fix!" > > -- john, KE5FX > >> -----Original Message----- >> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On >> Behalf Of paul swed >> Sent: Sunday, November 14, 2010 8:01 PM >> To: Discussion of precise time and frequency measurement >> Subject: Re: [time-nuts] How does one actually do Allan variation >> graphs? >> >> >> Really good advice on what to checkout. >> 5370s are the devil to fix if somethings wrong such as jitter. >> Good luck. >> Paul >> >> On Sun, Nov 14, 2010 at 12:40 PM, Bob Camp <lists@rtty.us> wrote: >> >>> Hi >>> >>> Like a lot of stuff, the going price for these has dropped. >> They get less >>> and less respect every day ... >>> >>> One thing that may be specific to me - I do not consider a >> 5370A to be any >>> more or less valuable than a 5370B. They both do pretty much >> the same thing. >>> The 5370B might have fewer hours on it, it might not. On average 5370A >>> prices seem to run slightly higher than 5370B prices. Why is a >> mystery to >>> me. >>> >>> Bob >>> >>> >>> On Nov 14, 2010, at 11:57 AM, William H. Fite wrote: >>> >>>> Thanks, Bob >>>> >>>> He's asking $400 but I can tell by the look in his eye that he'll take >>>> substantially less. >>>> >>>> He's a lousy poker player, too... >>>> >>>> I asked him to turn it on about 0900 this morning and I'm >> going over in >>> an >>>> hour or so to check it out. >>>> >>>> Thanks again, >>>> >>>> Bill >>>> >>>> >>>> >>>> >>>> On Sun, Nov 14, 2010 at 11:44 AM, Bob Camp <lists@rtty.us> wrote: >>>> >>>>> Hi >>>>> >>>>> Assuming: >>>>> >>>>> 1) All the knobs and switches are intact and working >>>>> 2) All the led's in the display work >>>>> 3) All the alarm and indicator LED's work >>>>> 4) The input amps are good >>>>> 5) All the connectors are intact >>>>> 6) The OCXO is good / on frequency >>>>> 7) It passes the diags >>>>> 8) Jitter is down below 100 ps ( should be below 40) >>>>> 9) You can check all this out before purchace. Let the beast >> warm up for >>> at >>>>> least an hour before you check it. >>>>> >>>>> Something in the $180 to $260 range is probably fair depending on >>>>> cosmetics. You might start out at $150 in order to >> compromise at $200. I >>>>> certainly would not pay over $300. I know the list sounds a bit long, >>> but >>>>> I've seen 5370's with problems in each of those areas. Pretty much >>> anything >>>>> damaged / non-functional would knock a pretty good chunk off >> the price. >>>>> >>>>> Bob >>>>> >>>>> >>>>> On Nov 14, 2010, at 11:29 AM, William H. Fite wrote: >>>>> >>>>>> Gentlemen, >>>>>> >>>>>> What is a reasonable price for a 5370A? Local guy here is trying to >>> hawk >>>>>> one to me. Not cosmetically perfect but fully operational. >>>>>> >>>>>> Yes, I know someone is going to say, "I got one for 50 bucks." But >>>>> really, >>>>>> what is a fair price? >>>>>> >>>>>> Thanks, >>>>>> >>>>>> Bill >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> On Sun, Nov 14, 2010 at 10:48 AM, Magnus Danielson < >>>>>> magnus@rubidium.dyndns.org> wrote: >>>>>> >>>>>>> On 11/14/2010 09:41 AM, John Miles wrote: >>>>>>> >>>>>>>> >>>>>>>> I’ve looked at Wikipedia and I am as lost as when I started. >>>>>>>>> >>>>>>>>> Could someone walk me through the process step by step and also >>>>>>>>> tell me what test equipment is required? >>>>>>>>> >>>>>>>>> >>>>>>>> Besides the pointers at www.leapsecond.com , I've collected a few >>>>> links >>>>>>>> at http://www.ke5fx.com/stability.htm that may be helpful. >>>>>>>> >>>>>>>> The first .PDF link on that page is my presentation from the >>> Microwave >>>>>>>> Update conference a few weeks ago. It was meant as an >> introductory >>>>>>>> "Stability Measurement for Radio Nuts" talk, discussing >> the state of >>>>> the >>>>>>>> commercial art in light of what's available to hobbyists. >>>>>>>> >>>>>>>> The NIST links under "General timing and noise metrology", in >>>>> particular >>>>>>>> this one ( http://tf.nist.gov/general/pdf/2220.pdf ) are >> excellent. >>>>>>>> >>>>>>>> If you have an HP 5370A/B counter and a GPIB interface >> you can do a >>> lot >>>>> of >>>>>>>> good measurement work. With the appropriate software you can make >>>>>>>> conventional strip-chart style plots of frequency and >> phase, as well >>> as >>>>> ADEV >>>>>>>> and similar plots. Unless you are a software nut you >> probably do not >>>>> want >>>>>>>> to homebrew the necessary code to do this. Most people >> don't use the >>>>> same >>>>>>>> program for acquisition and plotting; a script or batch >> file does the >>>>> job of >>>>>>>> reading the data from the counter and spooling it to a text file, >>> while >>>>> a >>>>>>>> program like Stable32 or Ulrich Bangert's (search on >> df6jb plotter) >>>>> renders >>>>>>>> the graphics. >>>>>>>> >>>>>>>> My own app (TimeLab) is an exception, in that it attempts to do a >>> good >>>>> job >>>>>>>> at both data acquisition and rendering. It's still under heavy >>>>>>>> construction. Right now I'm rewriting all of the acquisition >>> routines >>>>> to >>>>>>>> support, among other things, the use of more than one >> GPIB counter at >>>>> once. >>>>>>>> >>>>>>>> Given that you have an HP 5370 available, if you wanted a >>> walkthrough, >>>>> you >>>>>>>> could try something along these lines: >>>>>>>> >>>>>>>> 1) Get an NI or Prologix GPIB adapter, install per manufacturer's >>>>>>>> guidelines. >>>>>>>> >>>>>>>> 2) Download the current TimeLab beta. You have two options here: >>>>>>>> http://www.ke5fx.com/timelab/setup.exe -- Graphically ugly but >>>>>>>> better tested >>>>>>>> http://www.ke5fx.com/timelab/setup_temp.exe -- Nicer looking, >>>>> but >>>>>>>> more likely to have bugs, and some features have yet to be ported >>> over >>>>> to >>>>>>>> the new codebase. Use this one for the instructions below. >>>>>>>> >>>>>>>> 3) Decide whether you want your HP 5370A/B to run in >> talk-only mode >>> or >>>>>>>> addressable mode and set its DIP switch accordingly. The software >>> will >>>>> work >>>>>>>> either way since it doesn't actually try to control the >> counter, but >>>>> for a >>>>>>>> 5370 I'd use addressable mode unless you have a reason not to. >>>>>>>> >>>>>>>> 4) Set up a basic frequency measurement to begin with. >> Feed a 10 MHz >>>>>>>> signal or whatever into the STOP jack, and hit FREQ and 1s. >>>>>>>> >>>>>>>> 5) In TimeLab, select Acquire->Acquire from HP 5370A/B, and then >>> select >>>>>>>> the NI interface or the Prologix interface's COM port >> from the list. >>>>> Hit >>>>>>>> the "Monitor" button and you should start seeing the counter's >>>>> frequency >>>>>>>> readings scroll by. If not, find out why before going >> any further. >>>>>>>> >>>>>>>> 6) Hit "Start Measurement." After a few readings have >> come in, you >>>>> should >>>>>>>> see your ADEV plot start to take shape. >>>>>>>> >>>>>>>> 7) Hit the 'f' key to switch to a frequency-difference >> chart, or the >>>>> 'p' >>>>>>>> key for a phase-difference chart. The 'y' key will >> toggle the Y-axis >>>>>>>> between easy-to-read round numbers and full display range. >>>>>>>> >>>>>>>> You can get somewhat cleaner measurements from the 5370 if you use >>>>>>>> time-interval mode rather than frequency mode, but time-interval >>>>>>>> measurements require a 1-pps or similar source and some additional >>>>> setup >>>>>>>> effort. >>>>>>>> >>>>>>> >>>>>>> 0) Essentially whatever source you have (crystal, Rubidium, Cesium, >>>>> GPSDO) >>>>>>> unless you haven't done it before, turn it on well in advance. I >>> prefer >>>>> days >>>>>>> over hours. Locked crystals such as Rubidium, Cesium and >> GPSDOs will >>>>> cancel >>>>>>> the last part of the oscillator drift but depending on details >>>>> performance >>>>>>> may be more or less compromised by this drift. I think >> this is one of >>>>> the >>>>>>> practical details one should not miss. >>>>>>> >>>>>>> I for one thinks that using a trigger signal such as the >> PPS or more >>>>>>> preferably a higher frequency trigger is worthwhile, as >> you get a more >>>>>>> stable rate of read-outs. Also, it gives a larger amount >> of raw data, >>>>>>> allowing for the increased degrees of freedom and quicker >> convergence >>> of >>>>>>> estimator(s). >>>>>>> >>>>>>> Do use TimeLab, I think it is a great way to get going. >> It's also fun >>> to >>>>>>> see the curve converge as more data comes in... >>>>>>> >>>>>>> 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. >>>>> >>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.