A near-field probe into a sensitive oscilloscope input might do it - or a contact with one of the crystal pins or the track. The easiest to make are a stub of stripped small-diameter (RG174) coaxial cable with the shield pared back a few millimetres, and a dot of glue to stop them shorting out. The next simplest is a small loop of coaxial cable assembled to form a loop antenna.
They won't interfere with the oscillator (no direct connection) but will probably need a low-noise amplifier to pick up the signal reasonably.
I wouldn't bother trying to beat it against another frequency source, but if you have a wideband shortwave receiver you could tune it to around 20MHz plus or minus 1kHz (so 19999 or 20001 kHz) and see if you get a 1kHz tone.
From the labels it looks like a short HC49 crystal, possibly 20MHz, made by NDK. It's rare to see those in sub-MHz frequencies.
They won't interfere with the oscillator (no direct connection) but will probably need a low-noise amplifier to pick up the signal reasonably.
I wouldn't bother trying to beat it against another frequency source, but if you have a wideband shortwave receiver you could tune it to around 20MHz plus or minus 1kHz (so 19999 or 20001 kHz) and see if you get a 1kHz tone.
From the labels it looks like a short HC49 crystal, possibly 20MHz, made by NDK. It's rare to see those in sub-MHz frequencies.
Statistics: Posted by philpem — Sun Oct 20, 2024 11:36 pm