Is the SW100 antenna jack safe to use with the DE-31 (KA-31) ? The
SW100 powers the antenna which comes with it -- so it outputs voltage
on the antenna jack... When I bought a Torus Tuner (Edek) loop, Ed
especially modified it (and future units) to work with the SW100, after
I requested it.

I actually tried it with the SW100 antenna jack and then reminded
myself that I probably shouldn't. I'm now testing it on the SW100 rod
antenna and the DE1105 rod antenna.
The DE1105 does have an S meter (I don't know what units they use).

My goal is to get the DE1105 with DE-31 to work and then sell my SW100
and Torus Tuner loop. The SW100 and Torus Tuner are both great... but
nowadays, I use shortwave mostly for travel and the SW100 is too
precious and the Torus Tuner is too big to bring along.