[TenTec] Coax connectors

[Dr. Gerald N. Johnson]

On Sat, 2008-05-31 at 08:59 -0700, Jim Brown K9YC wrote:
> On Sat, 31 May 2008 15:35:16 +0800, Marinus Loewensteijn wrote:
> 
> >When I was browsing around looking for dummy loads I noticed a lot 
> >of N connectors on these.
> 
> Mostly these are surplus from 2-way and cell phone systems. 
> 
> >I have only a few cables at this moment but more gear is due to 
> >come into the shack and I am not exactly thrilled with the use of 
> >the PL239.
> 
> >Out of the whole range of connectors that is available which are a
> >better solution to move to than the cheaply (perhaps better 
> >mentioned: junk quality) PL239?
> 
> There's nothing wrong with PL259 (UHF) connectors -- IF you buy 
> good ones. On another list, I noted that most connectors sold to 
> hams are junk -- imitations of the real thing with inferior metals, 
> plating, and insulating material. BUT -- REAL, good quality 
> connectors are still available. You simply have to go to 
> traditional electronics parts suppliers to buy them. In North 
> America, the good brand is Amphenol. I buy the silver plated 
> versions because they are MUCH easier to solder to. I pay about 
> $2.50 each in lots of 20-25. 
> 
> I can buy JUNK imitations of PL-259s for a buck or so. I can also 
> buy JUNK adapters (N to BNC, N to UHF, elbows, Tees, etc.) for a 
> few bucks, but they are cheaply built, have excessive loss, 
> inferior metals, and often fall apart. Examples of failures: I've 
> had four different N to UHF go intermittent and/or fall apart. I've 
> had Tees fall apart. I've had the dielectric of UHF connectors melt 
> and the center contact bend when I solder to it. I even bought one 
> bag of imitation PL259s with screw shells that were a quarter inch 
> or so short, so that they didn't screw onto a mating SO239! 
> 
> The WORST junk connectors are the imitation DINs sold for a buck or 
> so by ham vendors like RF Connection and others. Their insulation 
> melts when you try to solder to them, and you CANNOT solder to them 
> because the metal plating on the contacts don't take solder! REAL 
> DIN connectors are still available from mfrs like Tuchel and 
> Switchcraft. They cost $5-$7. I work in the world of pro audio. 
> We've tracked lots of problems with intermittent contacts to metal 
> problems in junk connectors sold by vendors like Radio Shack and 
> hi-fi shops. Again, REAL mfrs like Switchcraft, Neutrik, and 
> Amphenol still make quality products, but they cost more. You get 
> what you pay for. 

I've found that all multi-pin connectors whether DIN, or D type survive
soldering better when mated. Heat doesn't get to the mated connector and
so the pins being soldered can't migrate when the plastic softens. Its
true that some good makes used a thermoset plastic, but some good makes
also use a plastic that softens when hot.

Lots of off shore (or Pacific rim) connectors are nickel plated and only
the no longer available Ersin Multicore with activated flux will tin and
solder them. Plain rosin core solder will not stick. At one time, Icom
used nickel plated eyelets for through holes in PC boards in the IC-22S,
IC-211, and IC-245 and just encased the flared ends of the eyelets in
solder blobs. Those connections would go so open they wouldn't drive
CMOS gate inputs that need femto amps of current.

I never found the lifetime of Switchcraft XLR connectors to be good. The
female pins have too thin a wall and so loose their grip rapidly. The
rest of the Switchcraft family has always been very good.
> 
> And, of course, there are counterfeit parts. I serve on the 
> Standards Committee of the Audio Engineering Society, along with 
> engineers from many well known companies like Shure, Belden, AKG, 
> JBL, Neutrik, and Switchcraft. I have heard MANY reports of 
> counterfeit parts -- connectors, microphones, electronic components 
> -- that look absolutely identical to the real thing, complete with 
> logo and trademark.  

But are made of junk metals with faulty plating.
> 
> 73,
> 
> Jim Brown K9YC
> 
> 
73, Jerry, K0CQ