Here's how I connect a wire to my THF6 to listen to short wave.

I mentioned the SMA to SO-239 cable. A banana plug wil fit perfectly into
the center pin of any so-239. So, I attach the cable to the sma connector,
and then use a banana plug on the end of the wire. This gives a constant,
tight connection, and is easily removed.

A banana plug can be had at Radio Shack. Some must be soldered, while others
have a set screw which holds the wire in place.

The banana plug also fits the wire terminal of most tuners.

I have seen a bnc to banana jack adaptor, but not one for the sma.





Mike Duke, K5XU
American Council of Blind Radio Amateurs