On 22 December 2016 at 20:54, Bill Byrom <t...@radio.sent.com> wrote:
> Read about the synthesizer design of that generator here: > > https://ia600407.us.archive.org/10/items/Hewlett-Packard_ > Journal_Vol._42_No._2_1991-04_Hewlett-Packard/Hewlett- > Packard_Journal_Vol._42_No._2_1991-04_Hewlett-Packard.pdf > Cheers, I will do that. > > Dave, looking at the graph you posted it appears to me that the shift is > 10 Hz, not 100 Hz. It appears to me that is an audio spectrogram. I have > no idea if the frequency shift is in the generator or receiver. > Well done!. I thought I was told it was 100 Hz, but looking at the diagram, it is closer to about 10~15 Hz. The setup his end is a software defined radio, so the measurement of frequency is being done at audio. Unfortunately, I've been unable to get a response by phone, so I can't seem to get much in the way of technical details at this minute. I have an HP 5342A -- 10Hz to 18GHz Microwave Frequency Counter with 1 Hz resolution, but I belive this is moving (it is is), is quicker than the time it would take to measure to 10 GHz to 1 Hz. I can lock that to GPS easy enough, so the signal generator would be fed from the same reference as the frequency counter, but I don't think that would help. It would appear that measuring such small changes at microwave frequencies is not easy. Mixing with very good quality signal generator or known performance would probably be ok, but even old 20 GHz units are expensive. To get a good quality new signal generator would be a small fortune. I don't think even sending this to Keysight for calibration would achieve anything useful. I have not looked at the specification in detail, but phase noise is specification is -76 dBc at 10 kHz offset at 20 GHz. The calibration of this is high too ($1600 in the USA). > > Bill Byrom N5BB > Dave _______________________________________________ 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.