[Antennas] LMR 400

Sat May 30 18:31:29 EDT 2009

I am looking at my LMR400 right now...the center conductor is copper PLATED
aluminum....the BRAID is tin plated copper (I think) but it has the aluminum
sheath underneath...soldering to it does not make a good braid to sheath
connection....MOST of the time in SIMPLEX use, you MAY not ever notice
it...but in DUPLEX use?? FORGET IT!! Noise maker bigtime and I deal with
repeaters and duplex systems on a daily basis. I NEVER USE solder on LMR400
connectors...crimp is better with this type of shielding (yes I try to crimp
the sheath too...not usually done but it sure makes things better in the
long run in a rptr or multi freq use mode; such as using di- or tri-plexers)
OK, the company bought my crimp tool but I have been a crimper for the last
20+ years...I never solder a coax connector anymore, even on RG58....
Note: the new 1/2in Heliax connectors are no longer solder type on the
center pin...they use a captive center pin that grabs into the copper
conductor..The larger (LDF5 and bigger) Heliax uses a center pin that
THREADS into the center conductor...(well, not the new AL/Cu crap; thanks
Commscope for screwing up a good thing...but that's another issue!)
Heliax DOES not use solder..it is basically a CRIMP connector...so is a Type
N except for the center (and crimping that is SOOOON much easier and quicker
than soldering!)
With RF connectors on cable, its crimp or nothing for me! :)
Chris
WB5ITT 
-----Original Message-----
From: Ron Youvan
Sent: Saturday, May 30, 2009 5:11 PM
To: a
Subject: Re: [Antennas] LMR 400
 I have a spool of LMR-400/UF in the basement, but I don't remember if the
braid is copper or aluminum. If it isn't copper or tinned copper that is
the
soldering problem.
-- 
 Ron KA4INM - I'm proud to be Chuck's pop!