My homebrew off center fed dipole has always needed a tuner on 80 meters, but I discovered that by adding a 80pf to 130pf high voltage capacitor between the balun and the longer wire it lowers the swr and moves the lower swr up the band somewhat. My best swr on 80 was 2.4:1 at 3.5 MHz and quickly rose as I tuned up the band. I operate around 3.810 to 3.830 where the swr was around 3:1. I found a 120pf 5KV disc cap in my junkbox and decided to try it and it moved the useable swr up to 3.850 and dropped it to 1.5:1 with a <2:1 swr from 3.750 to around 3.950. The value of the cap determines the resonant point, so by varying the value, you can move the resonant point around within the band. Also, put a 1 megohm 3 watt non inductive resistor across the cap to protect it from static charges. Anyway, I can now operate 80 meters on some of my favorite frequencies without a tuner.