Topband: INVERTED_L_ANTENNA_MATCHING

EP Swynar gswynar at durham.net
Sun Dec 3 16:11:10 EST 2006


On 3rd December George wrote...

> Anyone have a idea of what I can use to match 52 ohm coax to my inverted L
antenna? The antenna is 120 feet on the horizontal and 50 feet on the
vertical.

George,

You have the classic Stew Perry (W1BB) extended inverted "L" there...!

I had the same thing here, & found that all you need to get a good match to
your feedline is to place an air variable capacitor at the base of the
vertical, between it & the feeder.

It does NOT have to be a wide-spaced "...bread slicer" affair, by any means.
Pick one out with a maximum capacitance of around 250-300-uufd., & you
should be good to go...

It helps, too, to have an assistant either adjusting the cap, outside, or
inside the shack keying the rig...otherwise you'll go through a lot of shoe
leather running in & out of the house checking the results of your "baby
step" settings of the capacitor!

One last thing: put the capacitor inside some sort of a weather-proof
enclosure, to protect it from the elements. I find that the large red &
black coloured plastic "Folgers"-brand coffee container works very well in
this regard...

~73~ Eddy VE3CUI - VE3XZ



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