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Old December 18th 14, 12:37 AM posted to rec.radio.amateur.antenna
Ralph Mowery Ralph Mowery is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 702
Default swr goes up on antenna

I have a home buit version of the Carolina Windom. An off center fed
antenna about 120 feet long with a 4:1 voltage balun and from the feedpoint
it goes to an inline ferrite bead choke 20 feet from the feed point, then 80
feet of rg-8 to the shack.

The balun is suspose to be rated for 3 kw. It does have 2 cores in it.
By tests, I know if I run ssb at over 800 watts the balun will heat up and
change the swr.

I have noticed lately that running just 100 watts ssb on 80 meters the swr
seems to be going up to about 2:1 and the rig cuts the power back as
expected as I talk from a starting point of 1:1. That has hapened for the
last two mornings. I don't recall it doing that before. The antenna has
been up for several years. It is just over 1:1 when normal on the frequency
I most often operate on. Today in the afternoon when 80 meters was dead I
transmitted a carrier for about 5 minuits and let off to ID, then another
carrier for about 5 minuits and the swr did not change.

Any ideas why the swr went up for the last two mornings, but did not seem to
go up this afternoon ?





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