N4XY asked recently about the length of the GAP Voyager counterpoise; it's 59'
(I had to check my manual which is at my Nova Scotia QTH). I've learned and
tried a few things that might be of general interest and start some discussions
(putting on my asbestos suit now):
I've used the GAP and a variety of wire antennas in my Nova Scotia QTH, VE1JF
(about 10 acres by a cliff 200' above salt water to the horizon), and am
presently planning more serious antennas for each band as I move up there
permanently. I chose the GAP because I have only been able to make period short
visits up there and could put it up and take it down quickly. I plan to keep it
at least as a backup antenna.
I have found as others have that the antenna performs relatively better on 80-20
(I get a lot of compliments and good "runs" on 80) than 160. My GAP sees salt
water to the horizon and yet is not competitive with some others' 160m setups
that on balance should not be any louder, considering
height/location/polarization, etc.
The resonances on 160 and 80 were not where I wanted them. There was no
indication in the manual re: tuning, but GAP advised:
o To move the resonance down from 3800 to low cw, add 5' to the length of each
counterpoise. (Haven't done that yet; am using tuner)
o To move the resonance up from 1800 to cover at least up to 1840, slip the
lowest thin rod up 3" and tape it in place (did it and seemed to help).
I made several changes to try to improve performance. I added a coaxial choke
between the antenna and the coax and violated instructions and (1) raised the
counterpoise wires a few feet above the ground except at 45o down to the base of
the antenna which is a ground level and (2) added 12 or 15 radials (so far) of
120-250+ feet. Resonance didn't seem to change radically vs. a few months
before, and 160 performance is still less than amazing, but 80 meter performance
seems to get more compliments and be more competitive; I get more sustained
runs into Europe and my S&P response seems better.
Would particularly welcome dialogue re: raising the counterpoise or maybe even
the whole antenna.
Jim Fisher, VE1JF/W8JF
reply to: 74273.2073@compuserve.com
The initial resonances on 160 and 80 were not what I wanted, and I received some
counsel from the factory on adjusting each of them, although it is not obvious
from the ads or manual that the antenna can be or needs to be tuned. On 160,
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: K7LXC@contesting.com
Sponsored by Akorn Access, Inc & KM9P
|