Ron D'Eau Claire wrote:
One BIG factor is whether you are using a balun in the system. I've yet to
find a balun that isn't unpredictable and frequently lossy when used in a
feedline with high reactance, that is any balanced feedline with an SWR much
above 1:1, no matter the type.
For just that reason I still use a link-coupled fully-balanced tuner when
feeding my doublet with open-wire line.
The losses in a balun all depend on just how high the SWR on the line is -
that is, how much reactance is present.
............................................................................
............
AMEN !! Seems to me that baluns of the *transmission line* type
have become *magic boxes* and so often used with high load (feeder) VSWR -
say >3:1. Just because the balun does not get hot or explode at the
transmitter power used, leads folk to believe that the balun is not adding
loss. Perhaps the habit of some manufacturers of Antenna System Couplers who
put a balun at the antenna feeder side of an unbalanced T or L network to
save cost has something to do with this.
4 wire cross connected line is very useful, especially at VHF. The
loss due to radiation is considerably less than the radiation loss found in
2 wire line, the ohmic loss is less since each *side* consists of two wires
in parallel, and low Zo lines can be built e.g. 200 ohms.
Ron, you have made my day !
73,
Geoff,
GM4ESD
_______________________________________________
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com
