A while back I purchased a low cost TCXO which I then used as the reference for a synthesizer generating 10GHz. Listening to the output on an SSB radio, the tone was hopping in a random fashion over four frequencies, spaced a few tens of Hz apart. This was surreal! I had, at that time, been building Multifrequency Shift Keyed data sources ( for WSJT modes) by programming synths directly, but this wasn't the case here. Yet the hopping tones sounded just like the modulation I would eventually be adding. Double checking, then again, then again. that I hadn't inadvertently programmed the synth controller PIC with the wrong code, had to come to the conclusion it was the TCXO using a PRN sequence to effect digital temperature/frequency compensation. At its 10MHz fundamental, each hop would have been a few tens of millihertz.
But it was very weird at first, hearing what sounded like a familiar modulation on a synth that wasn't programmed to generate it. There were four tones hopping in a (presumably pseudo) random manner, and the WSJT mode I was going to use, JT4, had... four tones that hop around. Andy www.g4jnt.com On Fri, 18 Feb 2022 at 10:19, Erik Kaashoek <[email protected]> wrote: > During long term testing of some 10 MHz TCXO the output frequency seems > to jump within one second 20 mHz ( millihertz) up in frequency every > > _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
