I mentioned at A walk through of a practical application of AIMuhf/AIM900 that I wasn’t all together happy with feed point R at resonance, at 40Ω it was perhaps a touch high for a 2m quarter wave ground plane on a largish vehicle roof.
Repeated measurement of the DC resistance from the coax plug sheild to car body yielded unstable resistance ranging from 1 to 10Ω. If stable low DC resistance is not achieved, this feed line won’t work properly for RF. Continue reading A walk through of a practical application of AIMuhf/AIM900A #2