Today, while perusing the wares at a local marine outfitting
store, I came upon 300 foot reels of 20ga. 7-strand copper
wire intended for use as "fishing cable".

Cable TV uses a multi-core cable with aluminum shield. If suspended above
ground between houses then there is also a steel wire around it, at least in
my area. The steel makes a good antenna, and a thumb-tack makes a good
contact with the aluminum shield.

Fence-wire in our neighborhood makes a good 160-meter antenna, and it is
already erected ;-)

Try loading your 80-metre TX into the telephone cable, providing it does not
lead underground.

In Northern climates they have 2 parallel 20-metre long metal rod,s like a
ships handrail, to stop snow sliding off the roof and burying passers-by. Go
inside the roof space and connect to it.

There are loads of ready-made antennas without having to buy anything at
all. Just use some of them when the neighbours are asleep (in this area that
is during the day).

CK