The tuner?(coupler)?should not need a counterpoise just? a good ground. That's why it is called a random wire length tuner.? The tuner should also be length insensitive (to a point - it won't tune a loop).? Before going to all this fuss with changing wire lengths and counterpoises... try pourning about 1 gallon of water mixed with as much road salt as will disolve into the water?onto both ground rods. Disconnect the rods from?gnd strap?before doing this just?to be safest.??
?
I have one of these FC40's and I'm not too impressed with it so far compared to the SG230.
?
'73
JD
VA7BTL
wb0m wrote:
I thought the rebar was to far from
> the tuner so I drove a 5 foot chunk of copper pipe into the ground
> right below the tuner. Testing afterward showed that I could only
> tune 20 meters through 6 meters. I am baffled by this. Clearly the
> copper tube and shorter ground wire should function better that the
> rebar and 15 feet of wire or is the long ground wire to the rebar
> acting like a counterpoise?
You have a good ground now, but a counterpoise is also needed. Add as
much wire as possible in the crawl space, but a couple of wire as far
apart as possible as long as possible in all directions of possible
(check a counterpoise diagram for any vertical antenna and you'll get
the idea).
You will also need to add or subtract wire from your
antenna. Here's some "favorable" wire lengths from the AH-4 reflector,
with the range parenthesis.
40' (35-44)
58' (52-64)
76' (70-81)
73, Jeff/wb0m
