[Elecraft] KX3 antenna question: Using 'remote' groundplane and random wire

[Andrew Moore]

Forgive me for what may be a silly question, but I've looked through the
ARRL handbook, done the google searches, etc. and haven't found a solution.

At the risk of starting a thread that may be more suitable for an antenna
forum, I'm asking the Elecraft list in hopes that the KX3, KX1 and K1 users
may have had experience here.

I've got two main operating positions: One in an aluminum-skinned trailer
which goes camping, and one in my shack with said trailer parked in the
yard.

For the camping scenario, for ease of use and simplicity, the KX3 sits
inside the trailer with its built-in antenna tuner's ground connected to
the shell of the trailer, and the hot side going to the random-length wire
tossed into the trees. Works great.

For when I'm home in the shack, I'd like to take advantage of the trailer's
metal shell as a ground plane or counterpoise for a random-length wire,
which could be either the same one from the trailer, or a second one in the
trees.

However, most of the random-length antenna solutions I've seen have
involved having the ground plane (or counterpoise) located at the tuner
itself, which in the case of the KX3 means at the KX3 itself, in the shack,
about 100 feet from the trailer.

Essentially what I want to do is to run the signal from the shack out to
the trailer and have the radiator and ground plane "start" (and split off)
there.  However, I'll definitely need the tuner in this scenario, so will
having the tuner be located 100 feet before the split throw it all off, or
introduce imbalances along, say, a coax run from the shack to the trailer?

I get the sense this may be a very basic question but I admit I'm no
antenna expert so I'm asking the gurus.

To keep the noise level down, direct replies may be best, and I'll be glad
to summarize to the group if there's interest.

Thanks,
--Andrew, NV1B
maineware.net