"Ron Walters" wrote in message
t.net...
After reading several articles both on and off the WEB regarding a
center fed antenna, only one article mentioned a recommended length for
the feed line.

some antennas, like the g5rv rely on a particular length of feedline because
it becomes part of the antenna and radiates on certain bands. others use it
as an impedance transformer.

One article recommended odd multiples of a wave length is desirable at
the lowest operating frequency while other articles don't address this.

that is a myth that has been around for many years. there is no 'magic
length' that works better than others, except maybe the shortest length that
reaches from the antenna to the transmitter. The only reasons to use longer
lengths is if you need to use it as an impedance transformer because the
antenna isn't matched to the line, or to allow for future rearrangement of
the shack. what can be handy about the 1/2 wavelength line is if the
antenna isn't matched to the line impedance the antenna impedance will be
repeated every 1/2 wavelength along the line. so if you have a 300 ohm
antenna and a 50 ohm coax, every 1/2 wavelength along the line you will see
the 300 ohms again. this of course only works on harmonically related
bands.