Another RCA CT-100 discovery B8001599

[dtvmcdonald]

The easiest and best way to measure the self-resonant frequency of a coil
is with a grid-dip meter and freqency counter or SDR receiver to get frequency accuracy.

That's if they are unshielded. If shielded, feed from a signal generator
through a 270K resistor and measure with a very low capacitance scope probe:
hook a 0.5 or 1 pF cap inseries with a short piece of coax. IF picky you can of course calculate the unloaded frequency.

I used both methods on my commercial ones for my CT-100 and they agreed.
I suspect you will be appalled with the frequency response of the Q channel.