Hi Pretty simple:
Double balanced mixer, RPD-1 is one option, there are others. Fairly simple L/C lowpass between the mixer and an op-amp. 20 db positive (non-inverting) op-amp amplifier string after the mixer Output of the string goes to the sound card. Use a good (dual / quad) audio op amp Quadrature amp picks off the output of the first op amp stage, switch and resistors to set gain, pot to set op point. ==== So what you have is an old style quadrature phase noise amp and “PLL”. More or less a very junior version of the 3048 test box. Like any setup of this sort, you check two similar oscillators. They run in quadrature and you do a few “measure this with switch in position A” sort of things to set things up each time. Nothing exotic. Bob > On Mar 24, 2016, at 12:25 AM, Richard (Rick) Karlquist > <rich...@karlquist.com> wrote: > > > > On 3/23/2016 3:56 PM, Bob Camp wrote: > >> and standard covered. If you want to do spurs, spend $40 and build a phase >> noise test set that will drive the sound card on your PC. >> >> Lots of choices …. >> >> Bob >> > > Any documentation on this $40 phase noise test set? > > Rick N6RK > _______________________________________________ > 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.
