[TowerTalk] N connector, Re: UHF (PL259) soldered center

[Jim Thomson]

Date: Tue, 26 Jun 2018 08:12:52 -0700
From: jimlux <jimlux at earthlink.net>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] N connector, Re: UHF (PL259) soldered center


On 6/26/18 7:18 AM, Jim Thomson wrote:
> 
> ##  Forget what amphenol  states.  A  teflon PL-259  will hi pot test a heck of a lot higher
> than a  Type N.   Type N uses a puny center pin, identical to a BNC.

Actually not - .120" (N) vs 0.053" (BNC) - you're looking at that 
tapered guide pin, but that's not the current carrying part.


  The center pin
> on any PL-259 is huge by comparison.  There is no RF on the center pin any way. The
> RF travels down the outside of the mating female of the   SO-239. 

Uh.. Current in the center conductor is equal to the current in the 
shield. technically, current in the outer surface of the center 
conductor matches the current in the inner surface of the shield.


###  Hi pot test a PL-259 vs a   male...type N. 

## There is NO rf current flowing on the outside of the pin of  either a 
type N nor a PL-259.   The current instead flows  down the outside of the
mating female cylinder that the pin plugs into.   The center pin, or guide pin, is just used
to mate the bottom end of  the type N to the  bottom end of the mating female cylinder it plugs into...
which both have the same diameter.   I was not referring to the inner surface of the shield. 

##  PL-259  pin  is  30%  bigger  diameter than a type N pin.  Circumference is also 30% bigger.
Which means the PL-259 will  handle 30% more current.   30% more current =  69%  more power.   
But the actual current is flowing down the outside of the mating female cylinder..which is also  30%
bigger diameter in the case of  a SO-239. 

##  although Teflon coax, like  RG-393  will handle a lot of heat, you still have to be careful  with soldering the
center conductor on the coax male plug end.  They really should be silver soldered to take full advantage  of the
teflon coax.  Ditto with whatever is soldered to the mating chassis female..assuming teflon is also used on the female. 

##  I crimp the shields when using 7-16 Dins with stuff like LMR-600  +   RG-393...using the crimping tool. 
LMR-1200 uses an expanding ferrule on the inside of the copper center tube.  The braid is clamped. 

Jim   VE7RF

Jim