Wow, thank you for all of the advice everyone. Apparently I have some
more reading to do...

In the meantime I put together an off-center dipole 48" up 18" down
using aluminum wire. I understand there are probably better options,
but this provides significant improvement over what I had before.

Just one question about this antenna - how would one estimate the
impedance? I don't have an impedance analyzer. I have read in this NG
that the impedance will be roughly 300 Ohm, and that a TV-type balun
would bring it down to 75, which would be better than 300 if not
ideal. I have read elsewhere that it will be roughly 75 Ohm and no
balun is necessary. What is the truth?

I do have a 4:1 balun that would work if impedance is around 300, but
if impedance is around 75 would there be any benefit or harm in using
it?

Thank you all again,
Paul