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Ian Jackson[_2_] · June 11th 09, 10:43 AM posted to rec.radio.amateur.antenna

In message
,
writes
On Jun 10, 3:360 Is it advisable to use a combination of Coax and a ladder line to feed a
simple horizontal multiband dipole antenna?

In my new QTH it would be very easy for me to get a short run of coax out of
my shack window but I would like to use a low loss ladder line for the main
run up to the antenna feed point. Is it OK to place a 4:1 balun just outside
of the window 0
Kash, AG4EL

The G5RV antenna uses a combination of coax and ladder line, so this
type of antenna is in use by 1000's of Hams.

The 4:1 balun is a bad idea for a multiband antenna, due to the
impedances involved at the various operating frequencies. Just
transistion from the ladder line to the coax and use a 1:1 choke balun
at the antenna input of your tuner. You did not mention an antenna
tuner, but you will need one for multiband operation.

In general keep the coax length as short as possible.

If I remember correctly, the original design of the G5RV does NOT use
coax. [If interested, check it out on Google.]
--
Ian