Denton wrote:
I used to run the doublet with vertical drops on the ends, but found that
any vertical drop on the ends of the antenna really picked up the racket.

Same as at my QTH. Anything vertical is noisier on receive.

If I left the vertical drops off the ends, I never did like the way the Johnson
Matchbox was coupling with the feedline...450 ohm...on 80 meters.

Because your feedline length was somewhere in the ballpark
of 1/4 wavelength and presented a very high impedance to
the Matchbox. Ladder-line feedline lengths for low-impedance
antennas need so be close to multiples of 1/2 wavelength,
a little over 100 feet on 80m. Unfortunately, a lot of
ladder-line-fed 80m dipoles and loops are closer to 1/4WL,
around 60 feet or so which may be worst case for limited range
tuners like Johnson Matchboxes and internal autotuners.
--
73, Cecil http://www.qsl.net/w5dxp