Re: Topband: Beverage strain auto-disconnectsOf course it stretches if its
stressed but it also adds to the total strength. I would expect the WD-11A and
the nylon line to be supported at regular intervals.
Ive read somewhere that the older rural C line has a cloth embedded insulation
that can absorb moisture, dont know about the later versions.
In the past Ive used single strand rural telephone wire using #12 Copperweld
with a thick black vinyl jacket. Never once in over 25 years at 2 locations has
it ever broken with any tree across it.
Carl
KM1H
----- Original Message -----
From: Bill Wichers
To: zr@jeremy.mv.com ; w8ji@w8ji.com ; topband@contesting.com
Sent: Saturday, July 21, 2012 9:45 PM
Subject: Re: Topband: Beverage strain auto-disconnects
Typical "fishing line" is made of nylon. Nylon will stretch far more than the
steel in the WD-11A and will be of limited usefullness as an additional
strength member as a result. This is a similar problem to that of fiber optic
cable since the glass fiber doesn't stretch. In fiber optic cables where high
strength is required aramid yarns are generally used (like kevlar) due to low
stretch properties of that polymer.
If WD-11A isn't strong enough the next best option is probably just a
higher-strength/heavier wire of equivalent design. The nearest substitute I'm
aware of is rural "C" wire (basically telephone service drop cable). I have
previously referred to that type of cable as "superman's zip cord". It is
basically zip cord with two wires that are each solid copper clad steel of
about 16 gauge if I remember correctly. I would estimate it has a break
strength of 500+ pounds although I haven't ever tested it for tensile strength.
There is a newer type of telephone drop cable that has a single 22 gauge
copper pair molded into a jacket containing glass reinforcement. The only
conductive part of the cable is the copper pair (and it's solid copper wire).
This might be useful to replace WD-11A as well and is probably cheaper -- and
definetely is lighter weight -- than rural C wire. If anyone is curious I can
look up the spec number for that wire and post it.
-Bill
[Sent using Blackberry Messaging]
----- Original Message -----
From: topband-bounces@contesting.com <topband-bounces@contesting.com>
To: Tom W8JI <w8ji@w8ji.com>; topband@contesting.com <topband@contesting.com>
Sent: Fri Jul 20 19:07:45 2012
Subject: Re: Topband: Beverage strain auto-disconnects
If the WD-11A is so weak and a repair problem why not support it on one of
the higher strength fishing lines as a messenger?
Carl
KM1H
----- Original Message -----
From: "Tom W8JI" <w8ji@w8ji.com>
To: <topband@contesting.com>
Sent: Friday, July 20, 2012 12:59 PM
Subject: Re: Topband: Beverage strain auto-disconnects
>> However, single wire Beverages are out. The only way I can have
>> Beverages in more than a couple of directions (south, southwest, and
>> west) is to make them reversible. All feeds have to be on the end
>> that is on high ground so that leaves two-wire Beverages with a
>> reflection transformer at the far end.
>
> I see now.
>
>> I settled on WD1A wire for ease of installation. BUT the stuff is a
>> nightmare when it breaks! It is never a clean break, but rather a
>> badly frayed section at least several inches long. Over time the
>> Beverages quickly shorten from cutting out the bad section and
>> splicing, requiring re-adjustment of the end points and/or splicing
>> a new section in. Splicing the stuff is not fun with the steel
>> strands, and splices must be COMPLETELY waterproofed or else the
>> steel strands rust through and the wire becomes too weak. Not to
>> mention the tinned copper strands seem to get "eaten" by the rust.
>
> This is exactly the problem I have with Wireman stranded ~400 ohm ladder
> line. After a few years, if water gets inside, conductors rust through.
>
> Heat from soldering also seems to remove the ultra thin copper layer over
> the steel core. I suspect that wire is not copper clad, but some sort of
> copper flash or plate.
>
> Anyway, I see now what you are doing.
>
>> I will admit I haven't tried "window line". I should be able to
>> install it with a level of aggravation somewhere between two
>> separate wires and the WD1A I now have. But I imagine that stuff
>> isn't the most fun to splice when it breaks either?
>
> The solid wire stuff is, IMO, much easier to splice. Stranded has the same
> problem you describe. It has to be watwerproofed, and heat removes the
> thin
> copper "whatever" on each strand.
>
> 73 Tom
>
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