I have used an end fed antenna on HF for years, fed with 50 ohm coax to the ATU. It works, but not ideal. After giving some thought to my antenna systems and the installation of an earth spike, I wondered about adding a balun to the longwire. Adding an unbalanced balun would provide a direct earth and isolate the coax feed from the antenna. This should reduce any static noise from the longwire. With the 9:1 balun there should be an impedence of around 50 ohm at the coax feed through most of the bands. Also, the the earth wire is connected directly to the balun before going into the shack. I bought the balun from ‘Superyagi’ and was impressed with the build of the case and connectors. Today I went up the ladders in the cold and fitted the balun. Before fitting, I checked the noise levels on the lower bands and signal strength of a couple of stations. Fitting was easy, so now I have a longwire with 9:1 balun attached.
9:1 balun attached to the 66′ longwire, note the connections smothered in vasaline for weather protection. Something I have sworn by for years now!
My first impression was that it was easier to tune the ATU on 160m and 80m. Before adding the balun 160m was quite tricky because the settings of the variable capacitors in the ATU were at their limit for tuning. Now it tunes in the centre of the capacitors quite sharply. The noise levels on 160m and 80m were about an S Point higher, but also the signals received were higher as well. It’s looking good, now I will try out the longwire system, particularly on 160m and 80m, to see how it performs on transmit. My first impression is a definate improvement.