[450] Loops are finally up to height... (pics)

[David McKenzie]

Don't take my word for it, it's a shunned practice throughout the amateur
community, because it results in shitty connections that either fail or have
wild impedance swings. Nothing else changed except moving the thing higher
up. It's your shoddy connector installation that is to blame, almost
guaranteed.

"One thing that you might consider, however, is that by taking the assembly
approach you have, you have completely violated the design intent of the
mechanical interface of the PL259, which is that the internal screw threads
in the back end of the connector body are intended to tightly screw on to
the jacket material (PVC, polyethylene, etc) of the coaxial cable, assuring
a very strong mechanical connection that cannot be broken by linear force.
The only way to "pull off" a properly installed PL259, even before it's
soldered at all, is to unscrew it. (And, of course, any weatherproofing
designed into the connector is lost as well, since you've left the four body
solder holes empty. And, of course, any impedance integrity provided by the
connector design is also lost, since you're terminating the center conductor
and the outer conductor in two different locations, in a non-coaxial
manner.) "

"And the thought of folding back the shield brings shudders to these old
bones. It was in fact, this very practice which drove me to write the
article in the first place. "

This is not CB where an extra inch down the connector for the shield does
not matter, at VHF frequencies it does. The only time you should be folding
the shield back is when you are using a UG-175/6 reducer, as that's the way
it's designed to be used.

On Thu, May 7, 2009 at 1:29 PM, Alan Fletcher <proaudio5 at hotmail.com> wrote:

>  Have to agree to disagree here, Dave. It's such a tight interference fit,
> that I literally had pain in my wrist from holding the cable as I tightened
> them down with a pair of needle-nosed Vise Grips.
>
> That's not to say soldering the braid is a bad idea, it certainly couldn't
> hurt. I just don't think it's entirely necessary.
>
> I'm toying with the idea of taking down the vertical completely and putting
> the top loop at the top of the mast. Not only will that reduce the wind load
> on my flimsy mounts, but it will also allow me more height... We'll see what
> happens.
>
> ------------------------------
> Date: Thu, 7 May 2009 09:57:51 -0400
> From: kb1fsy at vhfwiki.com
> To: john.foege at gmail.com; 450 at lists.vhfwiki.com
> Subject: Re: [450] Loops are finally up to height... (pics)
>
> Also, just twisting on the connectors and soldering the center pin is not
> adequate at VHF frequencies, you need to actually put the connector on
> properly.
>
> On Thu, May 7, 2009 at 12:45 AM, <john.foege at gmail.com> wrote:
>
> Use DSD to seal your connectors..heh
> Sent via BlackBerry by AT&T
>
> -----Original Message-----
> From: "Bob" <N1UJS at toast.net>
>
> Date: Thu, 7 May 2009 00:44:40
> To: 144.450 Mailing List<450 at lists.vhfwiki.com>
> Subject: Re: [450] Loops are finally up to height... (pics)
>
>
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