Ouch!
Thanks all, I am suitably chastened :-)
In my defence, I believe the basis of my advice (tune the aerial in the
first instance) remains sound.
Trev G3ZYY
In message <[EMAIL PROTECTED]>, Don
Wilhelm <[EMAIL PROTECTED]> writes
I agree with Kieth wholeheartedly. SWR on the feedline does NOT cause
feedline radiation - ever.
The thing that causes feedline radiation is common mode currents - most
commonly observed as current flowing on the outside of a coax line.
Properly placed current baluns can eliminate common mode current, but should
not change the SWR,
73,
Don W3FPR
-----Original Message-----
-----Original Message-----
Attempting to compensate for large mismatches with an ATU at the tx end
of the feeder may result in an apparently good match, but will in most
cases cause the feeder to radiate.
Exceptions to this are when the feeder is of the balanced variety, eg.
open wire, where the feeder carries a 'balanced' standing wave as a
matter of course.
---------------------------
Actually I believe this is one of the great myths of amateur radio.
Standing waves on the feedline do not create feedline radiation. What
standing waves do is to increase the loss in the feedline. Open wire
feeder is used to reduce feedline loss.
- Keith N1AS -
- K2 5411.ssb.100 -
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Trevor Day
Sunny Saltash
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