> Can you send me the pdf of the HP journal about the 5370? > If it's too big to attach, can you upload it to my web site? > dns: ftp.ko4bb.com > login: manuals > password: manuals You can download the August 1978 issue directly from the HP Archive site http://www.hparchive.com/hp_journals.htm . -- john, KE5FX (can't wait 'til Google starts indexing these...)

> Both links are great, thank you. Particularly, the 2nd one links to a > program to isolate the noise of 3 oscillators from 3 pairs of > comparisons. That's what I was looking for. Too bad the source code is > not provided, but if the program works, that'll be fine. The 3-cornered hat code looks something like this: A[i] = SQRT( (0 + SQR(AB[i]) - SQR(BC[i]) + SQR(AC[i])) / 2.0 ); B[i] = SQRT( (0 + SQR(AB[i]) + SQR(BC[i]) - SQR(AC[i])) / 2.0 ); C[i] = SQRT( (0 - SQR(AB[i]) + SQR(BC[i]) + SQR(AC[i])) / 2.0 ); The above source is from: http://www.leapsecond.com/tools/3hat.htm If you are a programmer see also this ADEV code: http://www.leapsecond.com/tools/adev1.htm /tvb

> Tom > > In comparing 2 oscillators do you mean > > 1) Connecting one oscillator to the FREQ STD input at the rear of the > 5370A, selecting the external timebase and connecting the other > oscillator to the Front panel FREQ/PERIOD input and then selecting > frequency measurement which in effect gives the frequency ratio of the 2 > oscillators? > > OR > > 2) Connecting the 2 oscillators to the LO and RF ports of a mixer, > lowpass filtering the mixer output and measuring the beat frequency? Sorry, I should have been clearer. No, neither 1) nor 2). Just keep it simple. Didier wants a text file of periodic phase differences as input to any ADEV tool so set the TIC to measure phase (or average phase). That's all. DUT1 goes into START and DUT2 goes into STOP. This works perfectly for kHz or 1PPS signals. It also works pretty well for relatively short runs of 5/10 MHz CW signals. /tvb