Cecil Moore wrote in message ...
Brian Kelly wrote:
A pair of caps
mechanically coupled via an insulated shaft coupling but completely
isolated electrically from each other should work.

Yes, that's what I had in mind. Mine are side-by-side with a
non-conducting fiber-chain connecting the shafts. Same with my
two rotary coils. When I said "dual-ganged", I meant mechanically
ganged, not electrically ganged.

| |/
Coax center wire--------|/|--------feedline--------
/| |
ganged variable caps to dipole
| |/
Coax braid--------------|/|--------feedline--------
/| |


OK , I got off on the wrong foot, this is more better. Tnx for the
clarification. Now back to Autocad so that I can enshrine it for
posterity . .

There are a lot of nice inexpensive instrument-quality parts out there
which make it quite easy to mechanically couple variable caps, rotary
inductors and I guess even pots but I've never seen that done. I'm
partial to the miniature timing belts and gears. IF they're not
wire-reinforced belts. For this tuner job there are plenty of options
available.

I had a monster remotely controlled tuner in the back yard for years
for my end-fed 135 inverted L. I used a pair of old WW2 Navy gun
director synchros, one in the shack which I cranked with a turns
counter and the other in the tuner cabinet to spin the big rotary
inductor via a small timing belt, never missed a lick.

w3rv