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[CQ-Contest] RE: [TowerTalk] coax cables

To: <towertalk@contesting.com>
Subject: [CQ-Contest] RE: [TowerTalk] coax cables
From: stevek@jmr.com (Steve Katz)
Date: Wed Feb 5 11:08:33 2003
Hi Jos ON4KJ,

I agree with you, too.

Regarding the "PL type" N connectors (2-piece, screw on & solder like a
PL-259), I've used thousands of these by now and they are fine; however,
they don't work like a "real" type N.

A minimal mil-spec type N (clamp assembly, captive pin, PTFE dielectric,
rubber gasket, flat washer, rear nut) like a UG-21D/U is very good up to at
least 3 GHz, and the better ones like UG-21B/U can be good to 12 GHz.  The
2-piece "PL type" N connectors are not.  They run out of gas at about 500
MHz, and I can measure an impedance bump and resulting attenuation at 1.2
GHz pretty easily.

Also, the "PL type" N connectors have an unfortunate problem in that the
insertion of the center conductor into the pin is a "blind mate."  That is,
you can't see what's actually going on, inside the connector, because as you
screw the connector body onto the coax jacket, it pulls the connector onto
the coax while the center conductor blindly mates with the connector pin.
This is not a good thing, especially if you use stranded-conductor coaxial
cable.  It's not bad if you use single-conductor coaxial cable like 9913 or
LMR400, because there's not much that can go wrong, there.  Either the
conductor lines up perfectly with the pin and inserts itself, or it doesn't.
And if it doesn't, then the center conductor is strong enough to literally
destroy the connector by pushing the pin completely out of the dielectric!
(And this does happen, if the parts are not precisely aligned.)

73,

Steve WB2WIK/6

"Success is the ability to go from failure to failure with no loss of
enthusiasm." -Winston Churchill

> -----Original Message-----
> From: j.a.hermans [SMTP:j.a.hermans@skynet.be]
> Sent: Wednesday, February 05, 2003 1:18 AM
> To:   Steve Katz; discreetly_confidential@yahoo.com;
> towertalk@contesting.com
> Subject:      Re: [CQ-Contest] RE: [TowerTalk] coax cables
> 
> 
> ----- Original Message -----
> From: "Steve Katz" <stevek@jmr.com>
> To: <discreetly_confidential@yahoo.com>; <towertalk@contesting.com>
> Sent: Tuesday, February 04, 2003 9:51 PM
> Subject: RE: [CQ-Contest] RE: [TowerTalk] coax cables
> 
> 
> >
> > Hi Chuck,
> >
> > I don't know who Paul is (my name is Steve) but I think this was
> > directed towards me.
> >
> > I agree with you.  Any time I see someone using a soldering "gun"
> > for a PL-259 installation, I cringe.
> >
> I agree.
> Assembling and soldering a PL should'nt be done elswhere then in a
> workshop,
> with adapted tools. A few hundreds one after an other in the ideal
> conditions is OK.
> It's a very critical operation if you dont want cold solder which break at
> the first occasion, or burned joints which have a transfert resistance of
> a
> few  M ohms
> .........Soldering guns !!!!!!!! throw them away, you will be unable to
> control the right temperature.
> Use a N type, sure you will have better results for years.
> By the way, nowadays one can find PL to be mounted as N-type. ( at least
> in
> Germany ).
> Have been in charge of ANGRC and other military production  for a couple
> of
> years in the late fiftees.......
> 
> Jos on4kj
> 
> 
> 
> > 73,
> >
> > Steve, WB2WIK/6
> >
> > > Paul,
> > >
> > > You hit the nail right on the head solidly and
> > > quite soundly.
> > >
> > > The operative word is 900W iron!
> > >
> > > HEAT HEAT HEAT!! Raise the mass of metal to the
> > > operating temp QUICKLY and then do the job. Too
> > > may hams use a 125W gun and wonder why it takes
> > > forever and they burn the coax, melt the
> > > dielectric and short the inner to the outer
> > > conductor!
> > >
> > > I work in MiL Quality world and I inspect this
> > > stuff on a daily basis aside from being NASA
> > > solder certified and nuclear industry solder
> > > certified.
> > >
> > > HEAT HEAT HEAT!!  Nothing beats a GOOD PROPERLY
> > > sized gun/iron!
> > >
> > > Huzzah for the excellent post!
> > >
> > > 73
> > >
> > > Chuck k3FT
> > >
> > > Give me that Old Time Mil-STD-454 requirement 5
> > > anytime!
> > >
> > >
> > >
> > > __________________________________________________
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> 
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