[time-nuts] TCXO improvement

[Greg Troxel]

Tom Van Baak <tvb at LeapSecond.com> writes:

> An email came in asking if it was possible to improve the performance
> of a TCXO if one monitors the temperature of the PCB or enclosure and
> then applies timekeeping corrections in s/w based on that data. I
> don't have specific P/N or other details so treat this as a generic
> question. Has anyone tried this?

Elecraft does this in the KX3 (ham radio).  Basically, the oscillator
has a calibration value anyway, and this makes it a function of
temperature.  Reports are that stability is much improved, particularly
for situations involving 2-minute transmissions and heating of the power
amplifier, with unavoidable thermal coupling to the oscillator, given
the low mass and size of the radio.

https://ftp.elecraft.com/KX3/Mod%20Notes%20Alerts/KX3%20Custom%20VFO%20TC%20rev%20A9.pdf

However, I'm not sure if the base oscillator counts as TCXO.

This scheme is of course lower power than putting an oven in the KX3.
Their larger radio (K3) has a better TCXO to start with, an option for
an OCXO, and an option for 10 MHz in.  But the KX3 is focused on
adequate performance with very lower power/size/weight.