Ulrich Bangert wrote: > Bruce, > > I have seen this specs before but do you know how to find the > schematics? > > Best regards > Ulric Bangert > > Ulrich
NO, I'm still looking, I presume you mean the NIST amplifier schematics and not the TADD-1 schematics at: http://www.tapr.org/~n8ur/ <http://www.tapr.org/%7En8ur/> JPL claim a phase tempco of about 1ps/K for their 1981 distribution amplifiers. It should be possible to achieve a phase noise floor or around -180dBc/Hz with a transformer coupled common base amplifier, but it can probably only achieve about 90dB isolation between outputs, by taking advantage of the 30 dB isolation between splitter outputs, without cascading common base stages which inevitably degrades the phase noise floor. It would be interesting to see if coupling via the common power supply limits the isolation of the TADD-1. The power supply noise may also limit the performance. Its easy to reduce the the power supply noise by 20-30dB with a low noise active filter or a low noise regulator. Bruce _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts