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@audiosystemsgroup.com>
To: towertalk <towertalk@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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