I'm getting back into radio after a 20 year absence. Back then, I had
a QRP rig and a novice license; didn't worry too much about my antenna
unless the SWR meter went past 2.5. What I did not have was an
antenna tuner.

Now that I'm older and wiser, I realize an antenna tuner is probably a
necessary thing to have. I'm putting up an 18' Hy-gain 5 band
vertical antenna, leading to a Yaesu FT840 @ 100 watts. The matching
ATT is not available, unless I'm willing to bid on E-bay for a hundred
more than it cost new. (Believe me, I've tried this.) But I don't
know what I should use. I know some tuners are designed for a
specific rig.

Does anyone know what I should get? I'd really just like to turn on
the radio, move to a frequency, turn on the ATT, and tap away. Help!