Topband: inv. L

[Charles Moizeau]

Before putting any kind of tape, gunk or goo on a fitting or soldered connection with the expectation of weatherproofing it in an outdoor environment, I ALWAYS do this first:  I wrap the item with two layers of half-inch wide 3-M blue tape used by painting contractors and widely available.  This product has very little tensile strength, but that is not needed in this application.  Its virtue is that, unlike almost every other tape, the adhesive never separates from the tape backing, with the result that even after years the protected item will be kept squeaky clean and uncontaminated by whatever was placed on top of it during the initial weatherproofing treatment.


I learned this after suffering the vexations of using liquid solvents in often unsuccessful attempts to fully clean up and disassemble a fitting or soldered joint covered with a variety of weatherproofing products, parts of which had migrated into the connection, mechanical or soldered.


73,


Charles, W2SH


________________________________
From: Topband <topband-bounces at contesting.com> on behalf of Art Snapper <art at nk8x.net>
Sent: Thursday, October 20, 2016 9:16 AM
To: 160
Subject: Re: Topband: inv. L

I had a few hours free yesterday afternoon, so I began the dual 80/160
radiator inv. L project.

In the process, I found that water had entered the coaxial center insulator
that was used at the feedpoint of the antenna.

Does anyone have a favorite solution for a weatherproof, coaxial feedpoint
for this type of antenna???

The radials are attached to several load center ground  bars, that are
screwed into a copper pipe that is driven into the ground.

The pipe gives me a rigid mounting point for some kind of insulator or
standoff.

BTW, after a temporary fix, I ran some quick SWR tests. There appears to be
very little interaction between the elements. At least from an SWR
perspective.

de Art NK8X

?

On Mon, Oct 17, 2016 at 11:16 AM, Art Snapper <art at nk8x.net> wrote:

> I was considering adding a second vertical element to my 160 inverted L.
> This one would be roughly a quarter wave tall for use on 80.
>
> I tried modelling in Eznec, but wasn't comfortable with the results. I may
> have screwed it up.
>
> Has anyone tried it for real? Is it a big compromise on either band? Would
> a switch at the feedpoint have any benefit?
>
> My inverted L has about 50 radials.
>
> 73
> Art NK8X
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
Topband Archives - Contesting Online Home<http://www.contesting.com/_topband>
www.contesting.com
Topband Mailing List Archives. Search String: [How to search] Display: ...


>
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
Topband Archives - Contesting Online Home<http://www.contesting.com/_topband>
www.contesting.com
Topband Mailing List Archives. Search String: [How to search] Display: ...