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[Amps] "N" Connector

To: <>
Subject: [Amps] "N" Connector
From: "Jim Thomson" <>
Date: Sun, 29 Dec 2013 23:56:17 -0800
List-post: <">>
Date: Sun, 29 Dec 2013 16:13:06 -0700
From: "Jim Garland" <>
To: "'Ian White'" <>, <>,
Subject: Re: [Amps] "N" Connector

I've had bad experience with N connectors on long runs of coax in the
wintertime. My theory, unsupported either by other facts or long
deliberation is that the coax length shrinks slightly at low temperatures
and tends to pull the center pin out of its making connector. The early
symptom is always an intermittent loss of receive sensitivity, but in really
cold  nights I've lost transmit continuity as well. Personally, I don't care
for N connectors (at least at HF frequencies) but in the olden days when I
was using lot of military Transco coax relays and motorized coax switches
there wasn't much of an alternative.
Jim W8ZR

##  You just nailed it.   Part of the problem is there is a lot of different 
type of N
connectors out there.....with and without pasivated  center pins.  The non 
types  would allow for the center pin to slide back a tiny bit....when its cold 
That’s when the int  RX and in extreme cases, TX  problems started up. 

##  I gave up on Type N..and  switched to 7-16 DIN.   Back in the mid 80s, 
stopped making UHF connectors for .875 inch heliax.  The only choices left  
from Andrew
is type N...and 7-16 Din.   Up until a few years ago, the telco where I worked 
these huge type N connectors on 1.25 inch and 1.625 inch heliax.   They are the 
size of a 
coffee  mug.... complete with this stupid tiny center pin.  They really look 
stupid when you see
them.   They also have to be carefully installed...and manhandling coax that 
big is no fun. 
Gotta been careful  so the center pin does not get damaged.   Normal deal was 
to  reduce down to smaller
coax for the last few feet, where it plugs into the various pieces of cell 
The center pin on a type N is  the same size as the pin on a BNC connector. 

##  The telcos and cell companies have all switched to   7-16 Din.    Type 
N...good riddance imo.   
The 7-16 din for bigger coax cables is the same or not much more $$  vs type N 
As far as I know, Andrew  still makes uhf connectors for  their .5 inch coax. 

later........ Jim  VE7RF

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