I received an answer from Tropic Aero (www.tropicaero.com):
They still have nicad batteries for the STS radio:
$49.00.

This beats the $70 (plus or minus) quoted from 'Batteries
Plus' for a nicad.

I do like the idea of a NiMH instead of the nicads.

Thanks,

Ray Lovinggood
Carrboro, NC, USA