I am using the MFJ G5RV, and have a coil of coax for balun purposes between
the ladderline and coax to the shack. My G5RV works fine.

Now, I'm starting to think about using it on 160m, as the MFJ instructions
say I should be able to do---with a bit of monkeying around.

MFJ says the G5RV, when configured as a single wire fed horizontal antenna,
acts a Marconi type of top loaded vertical.

Specifically, the instructions give me two options for 160M use. One is to
feed one side of the coax at my shack with a single wire to the tuner, and
ground the other side of the coax to a good earth ground or counterpoise. I
have no idea what this becomes in this mode.

The other option is to connect the coax outer conductor to the inner one,
and feed both with a single wire from the tuner, using a good earth ground
or counterpoise to the rig.

A question is what the consensus is as to which of the above feeds would be
the better?

I could remove the balun, and then feed one side of the antenna hot, with
the other side going to ground and/or counterpoise. Again, what would this
be?

The other question is whether or not I'd be better off with two long (maybe
100') counterpoise runs in opposite directions, as opposed to a good earth
ground only?

Help appreciated.