Mark Keith" wrote in message
om...
I might add...To me, the importance of using a better matching device
would depend on how long and how many elements, and also the freq.

This is an excellent point. I hadn't considered that the REAL-WORLD impact
of common-mode currents would depend on frequency and desired antenna
pattern.

My yagi is kind of on the borderline of the examples you mention, being a
fairly long-boom (18') 5-el yagi for 50 MHz. But front-to-rear is important
to me, as well as keeping the side lobes under control, so I've opted to
install a Radio Works line isolator (characterized to include 6M) at the
feedpoint of the gamma match, in preference to a simple coax air choke. This
should go up this afternoon, and we'll see how much difference it makes (if
any).

Bill / W5WVO