Quote:
Originally Posted by Ralph Mowery
I have a home built version of the Carolina Windom. An off center fed
antenna about 120 feet long with a 4:1 voltage balun and from the feed-point
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 suppose 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 happened 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 minuets and let off to ID, then another
carrier for about 5 minuets 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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Do you understand the difference between SWR and VSWR.
SWR is a Citizens Band Radio terminology that describes events on the feed line.
VSWR - Voltage Standing Wave Ratio refers to the voltage present.
If you increase the voltage, what happens to the SWR?
IT GOES UP!
For some reason you don't even know how to use speel check, yet you must think that you are some kind of antenna expert.
The permeability of the core of the balun is determined by it's quality.
It appears to me as if you are cheap and you bought the cheapest balun you could find, trying to save money.
If you do some research on the Carolina Windom antenna, you will read that if it's design frequency is 80 / 75m, that it will not work on 160 or 40m...
Even if it is designed for 80m, 80m is such a large band, you only get about 455 kc's of resonance, and everywhere else it is not resonant.
Had you bought a Guanella-balun and had this problem I would say that the Balun was bad. Because I do not know the origin of the balun you used, I can only make the same assumption.