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 < [email protected]> 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 -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
