"HK" wrote in message
. ..

John H. wrote:
On Tue, 25 Sep 2007 14:51:44 +0000, Larry wrote:


Another question: Most antennae seem to come with about 20 feet of wire.
Mounted on a console with the radio right there, I could get by with
about
3 feet of wire. Is all the extra wire necessary?



No. You can cut the wire to the length you need.


Not technically true, but probably doesn't matter in this application.
Performance of the radio is going to be marginal anyway. He'd be better off
coiling up the cable in a relatively large coil (not tight) for best
performance. It's length *does* affect proper antenna loading.

Eisboch

Eisboch wrote:
"HK" wrote in message
. ..

John H. wrote:
On Tue, 25 Sep 2007 14:51:44 +0000, Larry wrote:


Another question: Most antennae seem to come with about 20 feet of wire.
Mounted on a console with the radio right there, I could get by with
about
3 feet of wire. Is all the extra wire necessary?



No. You can cut the wire to the length you need.


Not technically true, but probably doesn't matter in this application.
Performance of the radio is going to be marginal anyway. He'd be better off
coiling up the cable in a relatively large coil (not tight) for best
performance. It's length *does* affect proper antenna loading.

Eisboch




wow, I guess Horizon and my installer knew what they were talking about.

On Tue, 25 Sep 2007 16:28:26 -0400, "Eisboch" wrote:

It's length *does* affect proper antenna loading.

And that's a *loaded* statement which gets debated in some circles
almost as much as "which boat is the best".

In theory the length of the coax does not matter, but that assumes a
perfect match with a SWR (Standing Wave Ratio) of 1:1. In practice an
SWR of 1.5:1 is generally good enough to ignore feed line length. This
discussion quickly gets very technical and into some very esoteric
transmission line theory.

Someone else mentioned the issue of being able to properly install a
coax connector which is also important. If you do not have the tools
or expertise, it is better to leave the coax uncut, or hire a
professional radio guy to do the job right.

On Tue, 25 Sep 2007 22:03:41 -0400, Wayne.B
wrote:


It's length *does* affect proper antenna loading.

And that's a *loaded* statement which gets debated in some circles
almost as much as "which boat is the best".

When I was at the ARRL and Technical Editor of QEX, I moderated a
panel discussion between Lou Varney, the head of the Lab, and the
editor of the ARRL antenna book at a seminar - there were other
professional RF engineers on the panel also.

The single most contentious issue was feedlines and their effect on
antenna loading.

I have a transcript of it around here somewhere. I'll send you a
copy.