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
> > http://lists.contesting.com/mailman/listinfo/towertalk
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