Topband: 160 wire yagi -- test info
GEORGE WALLNER
aa7jv at atlanticbb.net
Tue Sep 21 18:35:55 PDT 2010
>> Jorge Diez, CX6VM wrote:
>>
>> Anyone tried a 160 mts wire yagi?
>>
>>
>> Will appreciate some info about the performance and
>>construction.
Jorge,
Last weekend Carlos (N4IS) and I tested a two element
parasitic array.
The fed elment was an inverted L, with an 18 meter
vertical section and a 22 m long sloping wire. The element
was fed via an automatic antenna coupler (the one we used
on TX3A). Test frequency was 1,830 kHz. The reflector,
located 26 meters south of the fed element, was my 30
meter tall center-loaded vertical. A variable loading coil
mounted at the bottom was set to resonante the reflector
at 1,810 kHz. The array was mounted on my sea-wall, about
1.5 meter above sea-water. To the north and east of the
array there was open water while on the west side there
was good quality soil and a 25 m long swimming pool with
saline (low salt) water.
Carlos, whose QTH is 26 miles North of mine, was able to
measure a signal increase of 3 to 4 dB over the signal
radiated by the fed element alone. (The signal was
fluctuating due the antenna being flexed sideways by a
fresh easterly breeze.) While the tests were not
exhaustive, the results suggest that, when mounted over
highly conductive soil (or water)a ground (water) based
vertical parasitic array can provide meaningful gain.
I intend to conduct more thorough testing of a three
element array in November.
73,
George, AA7JV
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