Posted for "wpedwards" <wpedwards@hilgardhouse.com>:

From: Peter K More [mailto:peter@petermore.com]
Sent: Sunday, December 16, 2012 11:37 AM
To: wpedwards
Cc: rledwards9@yahoo.com
Subject: RE: [LML] Re: Which coax for antennae?

Hi Bill,

The there is a big difference between the RG58 and LMR400.  Here are the
mechanical and electrical difference:

RG58 or LMR195 <http://fieldcomponents.com/lmr195cableassemblies.html>

RG400 or LMR400
<http://www.showmecables.com/images/catalog/product/SpecSheets/LMR-400.pdf>


dB loss at 1000MHz per 100 feet

11dB

3.5dB


dB loss at 130MHz per 100 feet

4dB

1.4dB


Overall diameter

Same as RG58 ~.25”

0.405” (10.3mm)

The small planes we have short cable runs, good old RG58 will do.  The
modern version of the RG58 is the LMR195 (or ???-195 by other manufacturers)
Cable difference has to do with cable loss or signal attenuation at various
operating frequencies and length.  For COM/NAV at 108-132MHz, RG58 will do
fine.  With the transponder at ~1000MHz, there will be more loss using the
RG58.  The LMR195 is a slightly lower loss than the RG58.  I say unless
you’re flying a B29, using the 400 cable at almost ½” diameter (we call them
“hose”), you wont have enough room to make that U-turn behind the dash.  If
you have RG58, use them.  If you’re buying a new spool, buy the RG195 or
LMR195, we use those in our commercial installations.  Unless we have long
antenna cable runs at 2.4GHz, we use LMR400 as we did in HK Disneyland.

Critical for good signal pass thru is a good cable to connector (usually
BNC) connection or crimp.  L-Com is in Florida, buy their premade cables,
they are cheap and professionally built.  They will build them to your
specs.  www.l-com.com

Merry Christmas to you, Ann and Roger.

Peter