[TenTec] Connector tightening

n8cc at mei.net n8cc at mei.net
Wed Jul 27 22:26:28 PDT 2011


Guys,

If you stop and think about it, less than 1/10th of a turn beyond
'finger tight' is precious little.  It is, however, enough to make a
difference.

My experience has been, if I go 'just a smidge' past finger tight
with a small pair of 'puppy dog' pliers, and come back a year later,
ten out of ten UHF connectors will still be finger tight.

On the other hand, if I just go 'finger tight', a year later, nine
out of ten connectors will still be finger tight, and the tenth one
will invariably be 150 feet up my tower.  Put me in the 'just a bit
more than finger tight' camp.

73,   Jeff - N8CC

I saw that also...I went into my RainMan routine "oh no,  oh no".....

--- On Wed, 7/27/11, Ken Brown <ken.d.brown at hawaiiantel.net> wrote:


From: Ken Brown <ken.d.brown at hawaiiantel.net>
Subject: [TenTec] Connector tightening
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Date: Wednesday, July 27, 2011, 1:15 PM



> 2. Rechecked all connectors to make them "wrench tight"  All were
tight to
> the hand but about another 30 degrees of closure was gained by
using a small
> pipe wrench.  Did not check clix at this time.

Uggh!

For any type of quality RF connector (this does NOT include "UHF"
PL-255/SO-239 connectors) with knurled shells, additional tightening
beyond finger tight does not help to make a better connection. Unless
the shell has flat surfaces, ie. like a hex nut, no tool other than
fingers should be used to tighten it.

If the shell is designed to be tightened with a wrench it is obvious,
since it looks like a hex nut. In that case the amount of torque
used to
tighten it should be limited. There are special torque wrenches
available for this, but they are rather expensive. I suggest using
wrench with a handle no more than six inches long, and using only
one or
two fingers to push the handle as you finish tightening it. DO NOT grab
the wrench in your hand and give it all you've got. Remember you are
not
building an automobile engine, you are just connecting an RF cable.

Unfortunately with "UHF"/PL259 /SO239 connectors the tightness of the
shell DOES have an effect on the resistance of the outer conductor
connection. It does need to be tight, BUT with a clean, not corroded
connector, finger tight should be good enough. Any further
tightening is
likely to do more harm than good.

If you insist, as many people do, on using a tool to tighten knurled
outer shells on coaxial connectors, then use pliers with soft plastic
jaws, so that you do not mar the connector. If you can't buy a pair of
plastic jaw pliers, then wrap some tape around the jaws of some regular
pliers.

DE N6KB



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