Bruce Wilson wrote:
I was thinking that maybe the efficiency of an antenna resonant at 3.5 MHz
would be poor at 3.8 MHz where I want to use it. If there is no diminution
of efficiency when the tuner fixes the impedance, then I'll just keep using
it as is.

A G5RV that is resonant at 3.5 MHz would suffer additional
losses at 3.8 MHz because of the higher SWR but the ham
listening on the other end probably wouldn't notice the
difference. But for 10m, the difference between 28 MHz
and 29.7 MHz could certainly be appreciable.

Try a 1000 pf silver mica cap across the twinlead at the
twinlead/coax junction just on 75m. I think you would
like the result.
--
73, Cecil http://www.w5dxp.com