After trying a few configurations over the past week, I settled for the following antenna configuration on my deck: - 90' loop ( 40' x 5' ) of 14AWG stranded wire along the deck's ceiling - At the feed point, a 1:1 current balun connects antenna to 18' coax that runs to an auto tuner The antenna seems to work well on 40m and 20m and usually the tuner will match to below 2:1 SWR. I have been able to make contacts along the west coast and towards east coast running barefoot. That said, there are obvious flaws in how the antenna is fed. While the antenna is unbalanced, it is fed with a balun. Well, I used whatever I had in my junk box but now I am looking to improve it. Of course, the easier route is to stick a remote tuner at feed point but I want to understand what's at play here. Testing with an antenna analyzer (MFJ-259), I connected a 3' coax to the balun and analyzer. At the middle of 40m, resistance shows up at 500 ohms and SWR goes to beyond 3:1 in the red zone. Readings for 20m are the same. On 80m, the lowest SWR is 2.5 with resistance hovering around 100 ohms. When same measurements are made with an 18' coax, on 40m, the resistance hovers around 50 ohms and SWR is still in the red zone. On 80m, the SWR goes to 2 and resistance shows at around 75 ohms. So clearly the 18' coax has high losses due to high SWR. Right? Another test I did was connecting the auto tuner directly at the feed point and then run a coax from tuner to transmitter. The difference was night and day between this set-up and the former one of running coax to tuner from balun. A station from AZ that wasn't audible at all and was below the noise floor went up above the noise floor to 57-58. Now, even when I turned off the tuner that puts it in bypass mode, the AZ station was a good copy. That essentially means the 4:1 current balun built into the tuner improves matching significantly because in bypass mode only a 4:1 current balun is in path of the feed line. Questions I have are: 1. How does a balun impact the system when both ends are unbalanced? 2. How does a step down balun impact matching for a band/frequency that is already close to 50 ohm? For example, if the antenna presents an impedance of 100 ohms at 80m but 500 ohms at 40m then a 9:1 balun would help match 40m but what happens on 80m? Also, if someone can point me to good online text about baluns and impedance matching that is relatively mathematics free (if there is such a text) Thanks!