Dipole?

[PA5COR]

80 meter 1/2 wave dipole will work on 40/20 as well, ad 10.
Internal tuers will only do 1:3 SWR, nothing higher, so the external tuner will do a much larger SWR.
If the tuner has open line connection, go for open line ( ladder line) we mostly make it ourselves here .
The only little problem is feeding it n the house, after that just keep it away from metal and electricity lines, and just use it.
Getting the open line in the house, use window that opens and make fitting piece of wood with 2 copper or messing tapped studs through it, use wingnuts to disconnect quickly in case of thunderstorms.

Did that for several friends, works like a charm.
You can make a fan dipole, which is difficult to trim, or just use the above solution which will work as well
In case of the fan dipole and once trimmed for each band swr doesn't make a big problem and the internal tuner should handle it without a problem.
Negative- more wire, more weight to keep up and in trees better look out for giving it some space to work in wind.
100 feet is quite high, keep it a bit lower, there the trees move less.
Ideally a 1/2 wave above ground is for most of us not easy to do, but 1/4 wave above ground of the lowest working frequency works fine.

That is 60 feet for 80 meters.
Nice for 40 and for 20 perfect.

[KC2UGV]

80 meter 1/2 wave dipole will work on 40/20 as well, ad 10.
Internal tuers will only do 1:3 SWR, nothing higher, so the external tuner will do a much larger SWR.
If the tuner has open line connection, go for open line ( ladder line) we mostly make it ourselves here .
The only little problem is feeding it n the house, after that just keep it away from metal and electricity lines, and just use it.
Getting the open line in the house, use window that opens and make fitting piece of wood with 2 copper or messing tapped studs through it, use wingnuts to disconnect quickly in case of thunderstorms.

Did that for several friends, works like a charm.
You can make a fan dipole, which is difficult to trim, or just use the above solution which will work as well
In case of the fan dipole and once trimmed for each band swr doesn't make a big problem and the internal tuner should handle it without a problem.
Negative- more wire, more weight to keep up and in trees better look out for giving it some space to work in wind.
100 feet is quite high, keep it a bit lower, there the trees move less.
Ideally a 1/2 wave above ground is for most of us not easy to do, but 1/4 wave above ground of the lowest working frequency works fine.

That is 60 feet for 80 meters.
Nice for 40 and for 20 perfect.

FWIW, this is what I did, however, not for 80M (Not enough wire in the air yet). 300 Ohm twinlead right to the tuner in my shack.