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Re: [TowerTalk] PL259 Insertion Loss?

Subject: Re: [TowerTalk] PL259 Insertion Loss?
From: K8RI <>
Date: Tue, 17 Jan 2012 00:36:43 -0500
List-post: <">>
On 1/16/2012 8:11 PM, Jim Brown wrote:
> On 1/16/2012 2:19 PM, Peter Voelpel wrote:
>> Some PL259 stuff is suffering from production and /or material quality more
>> then type N
> You or your friends must be buying junk connectors!  The discussion is
> about QUALITY connectors, not JUNK. REAL PL259s and SO239s from good
> manufacturers do not have the problems you describe.  The rule in the US
> is Amphenol, Amphenol, Amphenol.  You may have other good choices in EU.
No connector maker produces 100 % perfect connectors, BUT Amphenol "in 
my opinion" is the best.
I've only had 2 bad Amphenols in all these years.  A connector with no 
threads and one with only half a center pin. Both were UHF type.  When I 
consider how many connectors I've gone through at 4 locations in over 50 
years that's a pretty good record.

OTOH by exceeding the connectors specifications (high voltage due to 
high SWR on 160 and 75) I've blown out a number N type Amphenols.  That 
was not the connectors fault. Excessive side pressure has also take its 
toll with barrels breaking off when equipment desks were moved and I ran 
out of cable before running out of move.  Connectors are not designed 
for that regardless of who made them.

> I can show you N-connectors that are junk. Further, N-connectors on some
> cables are well known to suffer from "creep," whereby the center pin
> recedes back into the cable, no longer making contact with the mating
> connector. This cannot happen with the UHF family of connectors.
Unfortunately that is a design flaw in N type connectors that is warned 
about in *some* assembly instructions.  IOW don't hang long vertical 
runs of coax from the connector. For those not familiar with this,   
what happens when a coax is hung from the connector  such as a straight 
run between the top and bottom of a tower, the center conductor *may* 
migrate downward enough that it pulls the center pin with it.  This is 
more common with foam dielectric cables.  Normally a drip loop (one turn 
coil) right at the top connector will prevent this from happening.  
Often this happens because the center pin at the other end of the coax 
was seated too deep (or not deep enough, depending on how you look at 
it)  and it moved out as the one at the other end moved in.  They need 
to have at least a little pressure on them.

To be fair I've had the jackets migrate out of clamp type UHF 
connectors, or have the jacket  pull out far enough to cause the weather 
proofing to fail on UHF solder connectors on long vertical runs. Again 
the single turn "drip loop" usually cures the problem.

Like others I plan on moving to all DIN 7-16 connectors, but I must have 
over 100# of N and UHF left.  Unfortunately now being retired and on a 
pension, plus having my climbing limited, this has to be an incremental 
upgrade.  I need to find a good source of 7-16 DINs to fit LMR-400 and 
600 that don't cost a fortune. I'm probably going to need close to 100 
time I'm finished.


Roger (K8RI)
> 73, Jim K9YC
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