[chbot] 10MHz OCXO Frequency Reference

[hamster]

Hi,

I've been playing around with 10MHz Oven Compensated Oscillator 
frequency references (both at work and at home).

At home I am experimenting on the <$20 CTI OSC5A2B02 based boards you 
can get from AliExpress. As they use "pre-aged" (salvaged) OCXOs, so 
their long-term stability should be quite good too. They are 
surprisingly good - can be calibrated to +/- 1 sec per year.

(For reference, a 2ppm 32.768kHz 'watch' crystal is about +/-1 sec every 
week and a standard 50ppm XO is +/-4 sec every day).

So far the only serious utility I've had at home was for testing the 
different loading capacitors on 32.768kHz oscillators, to reduce the 
drift of RTC clocks, but have been very helpful in understanding how to 
measure and calculate metrics like Allan Deviation for work projects.

This one with buffered outputs, USB-C power, and a well-filtered sine 
output is pretty good. I've got this one powered board with a USB-C plug 
in it, saving the cost of a power adapter: 
https://www.aliexpress.com/item/1005007915101405.html

The $14 boards (like  
https://www.aliexpress.com/item/1005009100732400.html ) are still pretty 
good, but really need a case improve their performance, and their own 
power supply (as they need to be on for a while to warm up the OCXO to 
get to best performance).

Anyhow, if anybody needs 10MHz for a one-off need, but can't justify 
$14, I'm happy to lend one, and can help calibrate a reference you may 
have against a GPS PPS.

Mike