Jobst Vandrey wrote:
1) I plan to run the SDR-1000 on 20 meters only into a 50 ohm antenna... 150 feet of RG-213 coax OR 150 feet of window line with 9:1 baluns at both ends?
RG-213 has about 0.8dB loss per 100 ft into a 50 ohm load at 14MHz. Add in the connectors and you've got ~2dB. A pair of baluns with balanced line between wouldn't be enough of an improvement to be worth the extra trouble.
My own experience is that balanced line is overkill at lower HF if the match is 5:1 or better, as long as you're using decent coax. Given how low our antennas are much of the time, the feedline losses are meaningless compared to how much power we're dumping into the ground or straight up into the clouds.
73 Frank AB2KT
