You wrote:

snipped for brevity

They don't make the antenna I am trying to use.

Yes, I can install my bit of wire into an FME male connector, but why
not just use a wire that's the same size as that FME connector's male
pin?

Here's another idea. Why not make up a metal _stylus_ that fits the FME
female connector on my SX66? Then, I'd always have my extra antenna
handy. Hm. My stylus is 4 inches long.

3*10^8 m/sec / (1900 MHz) = about 6 inches.

Doug