[TowerTalk] Re: N connectors

[Jan Erik Holm]

I´m not sure but I think Pete CEW might use old type N that
you solder, they are quite tricky.
N crimp made by Shuner (Germany) works excelent, also as
K3LR points out they have a "captivated" center pin, i e
after you crimped on the center pin and pushed the connector
itself on to it so it locks it can never be removed again
without destroying the center pin.
So my advice to CEW is to get crimp connectors and then get
in to his car and drive over to me so he can borrow my crimp
tool, but ofcourse 7/16 suff is the best.

73 Jim SM2EKM

PS: I´ve used these Shuner crimp N´s for almost 25 years
without a single failure, except when moist gets in to
them but thats another story.
---------------------------------------------------------------
Tim Duffy K3LR wrote:
> This exact problem of the center pin pulling back was terrible problem when Doc,  K8RR had his large contest station in Columbus, Ohio. All of his phasing and feedlines were "N" type and
> the majority had center conductor pull backs in cold weather.
> 
> The newer "captivated" center pin N connectors cure the problem. They are somewhat more expensive, but they solve the pin "floating" problem.
> 
> I am using good silver plated teflon PL-259's and SO239's. No problems with connector failure so far.
> 
> Be very careful using any SO239 that is not an Amphenol connector. I had terrible loss problems and intermittent issues with SO239s that were sent to me by ICE. Their off shore female UHF
> (SO239) connectors would not allow the center pins to seat all the way and the PL259 center pins were not "grabbed" by the connector either. It was amazing how things worked so much better
> when I changed out over 50 of their SO239 connectors.
> 
> 73!
> Tim K3LR
> 
> Peter Sundberg wrote:
> 
> 
>>I have done away with N-connectors in my VHF EME array as they are failing
>>during cold winter days. The problem is that at low temperatures (I live at
>>65.4N...) the center conductor of the coax gets shorter and the center pin
>>of the N-male is pulled out of the socket hence making poor contact. A
>>split second of 2kw RF vaporizes the center pin..
>>After having multiple failures during cold winters I now use PL259/SO239 of
>>good quality at the relay and as for the driven elements and powerdividers
>>I have soldered the coax direct and done away with connectors.
>>
>>I dont think these problems will occur in places where the temperature
>>swing is somewhat less than -40C -> +35C....
>>
>>73/Peter SM2CEW
>>www.qsl.net/sm2cew
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