Topband: Chokes for Beverages

[ZR]

----- Original Message ----- 
From: "Tom W8JI" <w8ji at w8ji.com>
To: "TopBand" <topband at contesting.com>
Sent: Thursday, June 21, 2012 3:47 PM
Subject: Re: Topband: Chokes for Beverages


>> Another reason to be leery of crimp connectors. My soldered connector
>> stubs
>> are still fine after 25 years at 2 locations in very high humidity
>> enviroments.
>
> Crimp connections are used all through the CATV industry, and many other
> places, and are just fine for many years when properly made. All of my
> internal house wiring is non-flooded, as are all the cables in my contest
> barn. There are millions of feet of non-flooded cables in MATV and CATV
> systems, which is also not a problem provided cables are properly 
> installed
> and correct connectors used.
>
> The real problem is using non-flooded cables outdoors, which with even a
> tiny hole will contaminate.
>
> Woven copper can actually be worse once it has been damp inside. Strands 
> in
> the weave tarnish, and cause high losses and poor shield performance.
>
> The advantage of foil is it has no weave, so surface corrosion does not
> deteriorate the cable nearly as fast as in woven conductors. The only
> problem, provided the shield has not corroded through, are end connections
> and the seam. Seam integrity is mostly problematic at UHF and higher.
>
> 73 Tom


The subject was LMR-400 which, of course, is not flooded and uses a tinned 
copper weave over aluminum foil.
If they decided to go with flooding I might even use it outdoors.

Of equal concern is the variety of crimp connector vendors as well as off 
brand 400 "type" cable.

Carl
KM1H