----- Original Message -----
From: "j.a.hermans" <j.a.hermans@skynet.be>
To: "Steve Katz" <stevek@jmr.com>; "'Mark Beckwith'" <mark@concertart.com>;
<towertalk@contesting.com>
Sent: Friday, February 07, 2003 9:35 PM
Subject: Re: [TowerTalk] Coax cables
> 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
> is'nt.
> 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
> rapidly.
> There is a long way to go from " envelope increaser " to a stable " coax
> connection ".....
> Sorry guys ....................
> Jos on4kj
>
> ----- Original Message -----
> From: "Steve Katz" <stevek@jmr.com>
> To: "'Mark Beckwith'" <mark@concertart.com>; <towertalk@contesting.com>
> 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
> an
> > ordinary PL-259 always fit it just fine. Better, in fact, than
> conventional
> > RG-213/U and such, because the center conductor really "filled" the pin,
> so
> > less solder would wick up during the assembly process. (Solder wicking
up
> > through the PL-259 pin, and application of excessive heat and solder
> during
> > 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
> *not*
> > 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
> N
> > 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
> stock
> > 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 [SMTP:mark@concertart.com]
> > > Sent: Friday, February 07, 2003 8:48 AM
> > > To: towertalk@contesting.com
> > > 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
> real
> > > 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
> 9913.
> > > Perhaps that was just a rumor too. I heard all this over coffee with
> old
> > > VHF geezers I met with every week back then.
> > >
> > > Mark, N5OT
> > >
> > >
> > > _______________________________________________
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> > > TowerTalk@contesting.com
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> >
> >
>
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