@tk 1. feedline does not have to be completely at right angles. 2. typically openwire or ladder line is mostly used at HF not a VHF although a few VHF/UHF moonbounce (EME) stations have used it. Use a good quality coax. 3. Impedance of ladder line can be quite a bit higher than 50ohm but a tuner is not suggested. If you must use a 300ohm <-> 50 ohm balun. 4. tough location as you are hemmed in quite a bit. Look up J pole you can make one with 300 ohm twinlead. Hang it as high as you can. 73 de va3db