[Johnson] [Boatanchors] Johnson Mobile inquiry

[k7nks at yahoo.com]

Metal housing on cheap coax fittings are sometimes made with pot metal or aluminum. They are plated with minimal nickel plate. A little wear and corrosive air starts eating them apart. Brass or stainless bodies stand up much better.

Salt air really tears cheap fittings apart. Vietnam era rigs had problems like yours due to vendor cheating and the high humidity in-country.

Chuck, k7nks


Sent from my iPad

On Jan 8, 2014, at 7:14 PM, Brian Harris <cosmophone at yahoo.com> wrote:

> I am beginning a large equipment reduction.  Some of the first items to go will be some Johnson Mobile transmitters.  In anticipation of their sale I started working on them yesterday.  In doing so I discovered an unusual (to me) problem.
> 
> Both of the SO-239 connectors on the rear of one unit (serial number 50191) had deteriorated to the point that the metal housings were crumbling to pieces.  These connectors were apparently not made by Amphenol, as they don't have their name stamped in the face as is typical.   In fact, there is no manufacturer's name on the connectors.  I am curious if anyone has seen this phenomenon before and if there is an explanation.  There is no other unusual metal corrosion/problem in the rig.   
> 
> If you've never had the joy of working on these rigs, specially the rear panel, I would avoid buying one that has connectors that need attention.  I had to remove the center conductors and insulators from two other SO-239s in order to have two empty housings into which I could insert the existing center guts from the old connectors.  This task took about two hours due to the tight quarters.
> 
> If anyone is keeping track, I have serial numbers 50191, 50685, 50837, 50839 and 51121.  The latter has a small relay installed which I suspect is for PTT.  Does anyone have info on this change?
> 
> Last, I'm looking for a parts rig or at least a good send/receive switch (rear wafer or entire switch) and a good front panel (one of mine is badly rusted).
> 
> Thank you and very 73,
> 
> Brian Harris WA5UEK
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