Steve:

That's what I thought, but it's always good to be sure, I guess.  I am
planning to use RG8X as well for my 2-meter/440 installation in the trailer,
but that feedline run is even shorter--probably no more than 10 or 15 feet.

If it were going to be longer, I'd definitely use different stuff, but the
thin stuff is necessary because it has to fit into an even smaller area in
the front of the trailer where the VHF/UHF antenna will be.

Nothing is ever perfect, but hopefully this will all be good enough for what
I want to do.

73 and thanks again to all from Tom Behler: KB8TYJ

----- Original Message ----- 
From: "Steve Dresser" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, May 22, 2006 9:41 AM
Subject: Re: question about coax feed lines


> Tom,
>
> Line loss is more of an issue as frequency increases, and is of
> greatest concern on VHF/UHF (2 meters and above).  We could quibble
> about theoretical differences, but for an HF installation, I don't
> think you have to worry as long as the cable is good, and your
> connections have been made carefully.  Besides, it's only a 20 foot run.
>
> Steve
>
> On Monday 5/22/06 08:19 T Behler wrote:
> >Hi, all.
> >
> >I am finally making progress in terms of getting my new HF Predator
> >screw-driver-type antenna installed onto my RV travel trailer.  Hope to
have
> >it done by this week-end. ... My question is this:
> >
> >The person helping to install the antenna has already put Belden RG8X
coax
> >on the antenna.  The coax run will be about 20 feet, going from the back
of
> >the trailer to the inside where I'll have my Icom 718 HF rig.  We will
have
> >the coax running in a PVC conduit which will run along the frame of the
> >trailer, and the coax will come up through a hole at an appropriate spot
> >inside the trailer.
> >
> >Someone has suggested to me that I really ought to be using thicker coax
for
> >this purpose, in order to minimize loss.  I do have a 100 foot chunk of
RG8U
> >coax with a foam dialectric that I could get the needed coax from, but
don't
> >want to go to all the trouble of re-doing the already-existing
connections
> >on the antenna if it really won't make much difference.
> >
> >The guy who installed the original coax on the antenna looked Belden RG8X
up
> >in the ARRL antenna book, and found that it has .7 DB loss per 100 foot
on
> >10 mhz, so any loss for a 20-foot run would seem negligible to me.
> >
> >Am I ok here, or should I really consider the thicker RG8U stuff?
> >
> >I know there are likely to be a variety of opinions on this one, and I
> >suppose I could always change coax runs later, but I want to try doing
> >things right the first time if possible.
> >
> >Thanks as always for your very helpful advice.
> >
> >73 from Tom Behler: KB8TYJ
>