Two loops on one support
A few posts back I shared a model for an optimized 40M receiving loop. Last night I checked to see what it looked like on 30M and 20M – and was very, very pleasantly surprised. In the past, I had simply fed each corner of one loop with a feedline from the DX Engineering NCC-1 that I had – it was sort of an accident – but I figured since the NCC-1 is a balanced phasing device with attenuation – the attenuators act as the resistance on one side or the other and you end up phasing one end off the other.
Since the loop is of a very manageable size, I figure it might be easy just to build two loops and actually use the resistor opposite the feed point and then phase them to really null off the back. I think what I will do is start with just one loop and no resistors and see how one loop behaves – then try two loops.
All of this is especially fun because the support mast is only 8′ and I have the perfect open and easy place in the backyard to set this up. I hope to play with this this weekend. I did order these 75 to 50 ohm transformers for the feedpoint:
I might also try using potentiometers instead of resistors – just for fun.