Date: Sun, 29 Dec 2013 16:13:06 -0700
From: "Jim Garland" <4cx250b@miamioh.edu>
To: "'Ian White'" <gm3sek@ifwtech.co.uk>, <jtml@vla.com>,
<amps@contesting.com>
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.
73,
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
pasivated
types would allow for the center pin to slide back a tiny bit....when its cold
out.
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,
Andrew
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
at..used
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
gear.
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
anyway.
As far as I know, Andrew still makes uhf connectors for their .5 inch coax.
later........ Jim VE7RF
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