[TowerTalk] Fwd: Fwd: sealing PL259's

Tue May 26 19:53:42 EDT 2015

Use a thin sheet of  Silicone rubber in a "U" shape inside the pliers to 
protect the connectors.  It works for me, but I'm often too impatient to 
worry about a cheap PL-259 (Even Silver plated Amphenols are cheap)
BNCs are basically miniature N connectors, bur they lose a lot to scale 
and are very weak.  I've never seen them used outdoors.  It tales little 
strength to pull the coax out of one, making them an interconnect only 
for me.

N are stronger, but not as strong as a properly soldered UHF connector. 
They weather proof, but don't ignore the Coax seal and tape.  The last 
"clamp" N Type I used, ended up with a dose of epoxy in the braid seal 
(the weak spot for strength) making them a one use only connector. Not 
quite as good as oil filter wrenches but I've never seen one of those 
wrenches that small.

Some one mentioned using CRIMP connectors and I agree. Crimp connectors 
for  UHF and N-Type eliminate most of the strength problems. I've been 
using them since I first found out about them and the crimpers were 
expensive. I have crimpers with die sets from RG58 to LMR-400 and a set 
of dedicated for the larger LMR-600.  I have cable prep tools as 
well.Score the jacket deep enough so a little side pressure will snap it 
off.  Adjusting the blades to cut the jacket off is likely to nick the 
shield wires. When using prep tools (strippers) for cables with rubber 
like jackets such as the UF versions of the Times wire cables, use a 
"thin coat of silicone grease on the jacket where the solid surfaces of 
the prep tool will ride. They will keep the tool from grabbing the 
jacket and causing it to bunch up and sometimes tear.  Silicone grease 
is one of those double edged swords with little difference between just 
enough and too much. I can not emphasize the admotion, Do not get 
Silicone grease, even a tiny film, where you do not want it. Nothing 
will stick to anything that has Silicones on it

NOTE: A warning about prep tools. A "properly" adjusted one is great, 
but they can be a real PITA to get set up.  When working with multiple 
makes and sizes of coax which makes for a number of prep tools, I prefer 
to set a prep tool up for a specific coax and mark it.  I do the same 
for each cable size and jacket. It may take 4 or 5 "test" trials to get 
one of the three blade units set up properly.   Coax with foil and a 
fine Al braid is an exceptional PITA.  Those Al wires are very fragile.

Although I see a lot of comments on sealing the threads on UHF 
connectors, the major leaks come from where the jacket enters the 
connector.  The jacket needs to extend into the connector as far as is 
practical and be sealed.

As others have said, the UHF connectors were not designed to be 
waterproof and as such leak like a sieve at the threads and where the 
coax enters the connector.  I believe Jim mentioned, packing the 
connector with Silicone grease which eliminates the need for goop on the 
threads. Filled with grease, the threads will receive a healthy dose of 
grease when the connectors are screwed together.

73

Roger (K8RI)

On 5/26/2015 1:25 PM, Hans Hammarquist via TowerTalk wrote:
> Hi Jim,
>
>
> I was thinking about the "gray" thread sealer that doesn't harden. It would also be out of the UV-radiation being inside the threads. Should be no problem, more than cleaning the gook off.
>
>
> I don't like to "tighten with pliers" when you have a knurled surface on the nut (or screw for that matter). It's needed for the UHF connector but not on the N (or TNC) for a proper connection.
>
>
> Regarding N <-> BNC: The BNC is weather proof by specification. You will find a gasket on a "correct" BNC connector. I was also told that the cores of the BNC and the N connector as almost identical. You can, with good result, temporary push a male N onto a female BCN. The core of a male BNC also fit in the female N. You can check the dimensions for the N and the BNC you will find that they are within tolerances. The center conductor in the N is thicker to maintain the Z=50 Ohm, as there is no dielectric (beside air) surrounding the conductor.
>
>
> Hans
>
>
>
> -----Original Message-----
> From: Jim Brown <jim at audiosystemsgroup.com>
> To: towertalk <towertalk at contesting.com>
> Sent: Mon, May 25, 2015 11:02 pm
> Subject: Re: [TowerTalk] Fwd:  sealing PL259's
>
>
> On Mon,5/25/2015 6:49 PM, Hans Hammarquist via TowerTalk wrote:
>> Maybe even better; the type of plumber dope they use to seal the threads.
> When thinking about these materials, always consider the need to remove
> them. :)  3M 2228 and 33 are very good in this regard. Also UV.  Using a
> product (like plumber dope) away from its usual application requires
> answers to questions like this. :)
>
>> What I don't like with the PL-259 is the lack of springs to keep the
> connection good at the screen side. All other connectors have some type of
> spring that ensure a good connection such as BNC and N. You have to tighten the
> PL-259 "well" in order to keep a good contact and there are no insurance they
> will loosen up over time.
>
> Tightening a UHF or N connector with pliers is part of mating it. If
> you're not doing that, you're not doing it right. I consider a quality
> UHF at least as robust as N (remember the migration problem).  I  don't
> consider BNC a weatherproof connector, nor a good connector for
> permanent installations. Rather, I view it as one that is more suited for
> mating and un-mating, indoors, where systems are often being
>
> reconfigured.
>
> 73, Jim
> K9YC
>
>
>   
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-- 

73

Roger (K8RI)

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