"jimbo" wrote in message
...
jimbo wrote:


Thanks for all of the advice. I have one more question. Can I tune a
J-Pole antenna in my shop and then move it to the attic and expect the
same performance? In other words, is an antenna an antenna or is an
antenna and it's installation an antenna?

It would seem to me that if the antenna is tuned and works in my shop
it should work in the attic. Otherwise, how do "store bought" antennas
work?

Thanks, jimbo

I have built about twenty copper-pipe j-poles and I have found that with
five feet or so between the antenna and surroundings, the tuning doesn't
change enough to be annoying.

The copper pipe j-pole can be dropped into a pipe and hoisted into the clear
for VSWR evaluations if you really want to get gnats-assey about it.

Speaking of that, I have found that j-poles usually don't hit 1:1, even
when the low point is mid-band. However, after I get the best match,
I insert a 100 pF capacitor between the coax center pin and the antenna
and "Viola!" I stole that idea from the gamma match.