Shorten the shunt wire [gamma] to about 45 feet.
All that hardware on top of the tower makes the tower look very long to
Not exactly sure what capacitance will tune it at that gamma length,
but, if you used an antenna analyzer, you'd get it right in not much
time at all !
Jim Johnson - KC4HW wrote:
> Hello Everyone,
> Need a little help with shunt feeding a 80 trylon self supporting tower. On
> this tower there is a 4 elements for 20m on 36' boom with 4 elements
> interlaced for 15m. At 87' is 5 elements for 10m on 24' boom and at 95'
> is 2 element on 40m.
> The shunt wire (12 gauge) is at 65' space approximately 4' from the
> tower. Have determined that the approximately capacitance at the feed
> point is 280pf, however the lowest SWR appears to be about 3 to 1.
> Can anyone suggestion something to improve this situation?
> Jim Johnson, KC4HW
> Melbourne, Florida
> DXCluster RF Connection: 144.95
> AN Wireless Self Supporting Towers at discounted prices,
> See http://www.mscomputer.com
> Wireless Weather Stations now $349.95. Call Toll Free,
> 888-333-9041 for additional information.
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