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[TowerTalk] Coax cables

To: <>
Subject: [TowerTalk] Coax cables
From: (j.a.hermans)
Date: Sun Feb 9 12:41:38 2003
Hi Steve,

As we can state the discussion on coax connectors is still going on. It is a
good and important subject beause it seems a simple matter, but It sure
Just had a look at an older  AMP mil-spec. cat.
Surprised they dont talk about PL types.......should there be a good raison
there for ?
Something that came back in my mind, and nobody talked about here ( or I
missed it )
are the central pins outer dimension of the N-type as a function of
characteristic Impedance of the cable.
 RG213/U  50 Ohm  pin diam. = 2.25 millimeters.
 RG216/U  75 Ohm  pin diam. = 1.20 millimeters.
Mix them up in a system, and one can start fault finding for several hours
maybe days.........
So take care when mounting connectors on coax cables. As I said before its a
very critical operation, unless you dont care of a couple of decibels of
losses or some intermittend functioning gear. Personally never tried to send
a Kilowatt thru such a set up. But I can imagine that the solder will melt
There is a long way to go from " envelope increaser " to a stable " coax
connection ".....
Sorry guys ....................
Jos on4kj

----- Original Message -----
From: "Steve Katz" <>
To: "'Mark Beckwith'" <>; <>
Sent: Friday, February 07, 2003 5:11 PM
Subject: RE: [TowerTalk] Coax cables

> Hi Mark,
> I think those are both rumors or wive's tails.
> I've used 9913 since it was introduced to the amateur market in 1983 and
> ordinary PL-259 always fit it just fine.  Better, in fact, than
> RG-213/U and such, because the center conductor really "filled" the pin,
> less solder would wick up during the assembly process.  (Solder wicking up
> through the PL-259 pin, and application of excessive heat and solder
> this operation, is a leading cause of failures due to the cable dielectric
> melting.)
> There is no "special for 9913" PL-259 that I know of, made by anybody.
> However, a conventional mil-spec Type N connector, series UG21/U, will
> accommodate the oversized center conductor of 9913 and similar low-loss
> cables.  To resolve that problem, a few specialty manufacturers did start
> making (and still make) "special" Type N's just for 9913 and similar.  The
> only thing different is the pin itself, the rest of the connector is
> standard.  I simply buy machined-out and then gold plated center pins
> separately from the N connectors for this application; use the whole UG21
> connector but toss out the center pin, and use a specialty center pin
> instead.  One source of the pins is The RF Connection.  Joel seems to
> these and is willing to sell them separately.
> -WB2WIK/6
> "Success is the ability to go from failure to failure with no loss of
> enthusiasm." -Winston Churchill
> > -----Original Message-----
> > From: Mark Beckwith []
> > Sent: Friday, February 07, 2003 8:48 AM
> > To:
> > Subject: Re: [TowerTalk] Coax cables
> >
> > Steve [Katz] said:
> >
> > >(Or, possibly the 9913 doesn't
> > >meet its own specification!)
> >
> > I recall early 9913 had a larger conductor but they figured that out
> > quick and started making it smaller.  Perhaps that is just a rumor.  I
> > recall a brief period in the 80s when you could by PL-259s made for
> > Perhaps that was just a rumor too.  I heard all this over coffee with
> > VHF geezers I met with every week back then.
> >
> > Mark, N5OT
> >
> >
> > _______________________________________________
> > TowerTalk mailing list
> >
> >
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