On Sat, 06 Oct 2007 14:26:48 GMT, "Dave" wrote:


"Joaquin Tall" wrote in message
...
Hello All,

Brisk winds blew through our area yesterday and, unfortunately, my 200'
G5RV's feedline touched ground overnight.

This morning I noticed that there were chew marks over 40' of the
ladderline; most went deep enough to expose the copper wire underneath. We
live in the country...

I called the manufacturer; they told me that "splicing/soldering" in a 40'
length of 300 ohm line to replace the chewed up line would upset the SWR
and almost make the antenna useless. It's the solder joints [no matter how
small] that would mess things up.

That mfgr is not just blowing smoke, he's making an erroneous statement , hoping you'll bite and buy some more
of his product, and at the same time starting another myth that we don't need.

If you're using 300-ohm line I assume you're also using an antenna tuner to match the line to the transmitter.
If this is the case then the line impedance is immaterial, because you could remove the chewed-up portion and
replace it with 450-ohm or 600-ohm line, or whatever impedance line, and adjusting the tuner for an input of
50 ohms will have compensated for the different line impedances along the way. The only result from using
different line impedances is that the SWR will be different on the line sections having the different
characteristic impedances.

The length of 450-ohm line I had available wouldn't reach from the tuner to the terminals of my 80-meter
dipole, but I had a lot of 300-ohm line. So I just used the 300-ohm line to make up the shortfall in the
450-ohm line. Works just fine. Yours will too.

Walt, W2DU