They absorb the 'back wave'. Forward efficiency is unchanged, but half the
power goes into the resistors instead of radiating off the rear. See Kraus
or Johnson/Jasik, or back issues of RCA review.

--
Crazy George
Remove NO and SPAM from return address
"Tom Coates" wrote in message
...
http://www.tentec.com/3402.PDF

The writeup says the terminating resistors make it non-resonant. I wonder
how they affect efficiency.

Tom, N3IJ