[Boatanchors] Slightly, OT: MF-HF Coax cable loss with high SWR (long post)

[Rob Atkinson]

use a preamp in the feedline from the rx loop.  ICE used to make a
good one but I don't know if they have it now that the founder is a
SK.  DX engineering has a good one but it is much more expensive.  you
can probably HB one also.   another option is to get the MFJ phase
shifting nulling box and use the rx loop and dipole together to
receive and null a source of noise.  I think MFJ calls it the Signal
Enhancer or something like that.

73

rob
k5uj

On Thu, Sep 22, 2011 at 2:53 PM, Phil KO6BB <KO6BB at sbcglobal.net> wrote:

>
> NOW THE QUESTION.  The antenna is Coax fed, the coax run will only be
> about 30 feet, give or take. Normally at MW and HF, for receive only I
> wouldn't worry too much about "coax "loss" on that short of a run.  I
> have a 55 foot length of nice Mil-Spec RG-213 with PL-259's on each
> end.  I also have a nice long length of Mil-Spec RG-58 with no
> connectors that I could cut to length and use.  I'd rather not cut the
> RG-213 in case I want to add a higher VHF/UHF antenna in the future.
>
> So, the RG-58 would be my first choice for "receive only" at HF.  My
> only concern is that I realize that this antenna is going to have
> extremely wide SWR swings, and thus have SWR-loss across the 1-30MHz
> spectrum.  Is this loss on a 30 foot run likely to be significant enough
> to be of concern across the MW-shortwave spectrum, or should I just go
> ahead and cut the RG-213 to length and use that (it's too stiff to roll
> up and shove under the overhead shelf)?