Loops:
Some years ago I had a 6M loop, side mounted on my tower. Wasn't very high,
maybe 20 feet. I lived on the coast, at that time. I could talk ~100 miles up
and down the coast. Don't think I ever talked very far inland. One Sunday
morning I worked Argentina. Paul, KJ4G has had very good results with the Par
Loops on 6M. He really likes them. I have a M2 five element yagi on six meters.
I usually keep it pointed North. I do not know how much DX, to the South, I
have missed out on. If I ever put up a larger 6M yagi, I will consider a loop
for monitoring.
At my current location (Lakeland, FL) I have a two meter M2 loop, side mounted
on my tower @75'. I use it for monitoring 144.200. Depending on the station and
where their antennas are pointed, I can hear out to about 125 miles. It works
well for monitoring or talking to someone within 50 miles of me. The M2 loop is
a grounded antenna and I have a 1/4 shorted stub, where the jumper from the
antenna connects to the heliax. The heliax is grounded at the tower base. I
leave it connected to my IC 9100, all the time, whereas I disconnect the top
mounted yagis when I am not using them, due to the potential for a lightning
hit. It requires little effort for me to listen to 2M, using the loop - just
turn on the radio.
Those of you who have the Proceedings from the 2013 SEVHF conference can see
how I use loops with my FT 817. I side mounted a M2 432 loop on my tower. I use
it when I am net control of the FLWSS net, on 432.090. I start the net on the
loop, then switch to the yagi and go around the compass rose. I then close the
net on the loop. Really, a single loop on 432 just does not work that well.
There just is not enough capture area. I can be heard off the back and sides of
my M2 13WL about as well as on the loop. Do the arithmetic, allowing for
feedline loss, you would have to stack four 432 loops to equal the performance
of a single loop on 2M. When I need the heliax, for something else, the 432
loop is coming off the tower.
--
Buddy WB4OMG
_______________________________________________
VHFcontesting mailing list
VHFcontesting@contesting.com
http://lists.contesting.com/mailman/listinfo/vhfcontesting
|