Hi A multi turn (maybe 10 turn) pot and a few resistors can give you all you need to drive the OCXO once it's warmed up. If you want to investigate right at 10 MHz, you probably need two 10 turn pots.
Bob On Aug 31, 2013, at 9:05 PM, Hui Zhang <[email protected]> wrote: > Hello Bob: > That's good idea, I will try it at right time, in fact I collect about 300 > data by measured a OCXO warm-up, and I made a excel chart to analize the > relative of output digit and frequency. but it's very crudely because I use > little time to do it. I don't have a high resolution DAC, I will find a way > to do this test late. Thank you. > > > Here is a screen shot of my chart: > > > http://hkbbs.leowood.net:88/incomefiles/20139/18581578616.JPG > > > > Hui Zhang > > At 2013-09-01 07:51:24,"Bob Camp" <[email protected]> wrote: >> Hi >> >> One thing to look at - >> >> Take a large set of data and then sort it by reading. What you will find is >> that there are only certain numbers that come up. You can directly observe >> this with a good OCXO and a high resolution input to the EFC. >> >> Bob >> >> On Aug 31, 2013, at 11:06 AM, Hui Zhang <[email protected]> wrote: >> >>> Dear group: >>> >>> I found a strange thing about HP53132A’s output digit, I know the HP53132A >>> is a universal counter that have 12 digits per second performance by read >>> the manual. By use 10s gate time, I thought it will be 13 digits >>> resolution. But I found it can output more digits reads by use GPIB or >>> RS-232 way to collect datas. (This is simple way rather than use offset >>> method). I use RS-232 cable to connected to my counter to observe the >>> frequency of a OCXO, I got these output result ( a part of long sequence): >>> >>> 9.999,967,286,098,0 MHz >>> 9.999,981,814,726,9 MHz >>> 9.999,991,573,702,0 MHz >>> 9.999,997,482,253,0 MHz >>> 9.999,999,945,685 MHz >>> 10.000,000,472,030,4 MHz >>> 10.000,000,460,991,3 MHz >>> 10.000,000,352,570,9 MHz >>> 10.000,000,254,108 MHz >>> 10.000,000,183,759 MHz >>> 10.000,000,136,842 MHz >>> .. >>> . (Omitted few lines) >>> . >>> 10.000,000,039,724 MHz >>> 10.000,000,006,299 MHz >>> 9.999,999,992,692 MHz >>> 9.999,999,990,674 MHz >>> 9.999,999,989,094 MHz >>> 9.999,999,995,662 MHz >>> 9.999,999,993,829 MHz >>> >>> The question is in first four lines the reads is 14 digits, but in line 5, >>> the digits reduce to 13 digits, and then, it’s became 15 digits in line >>> 6(because over 10Mhz). After 3 lines, the reads reduce one digits again to >>> became 14 digits(also over 10Mhz), again after that few lines the >>> frequency less that 10Mhz, it return to 13 digits like last few line. My >>> question is what determines the HP53132A’s resolution? Why the output is >>> variable digits even the had very close frequency? Any comment will be >>> appreciate. >>> >>> >>> >>> Hui Zhang >>> _______________________________________________ >>> 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. > _______________________________________________ > 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.
