So you think the "black hair" I see might be contamination from the jacket
versus oxidation?
This could be significant, as I might have a chance to use a solvent to
clean contamination, but cleaning oxidation is probably hopeless.
Guess I need to get out there with the scrap pieces and see what steel wool
does versus cloth + solvents.
I think it's a lost cause, but am willing to put in a little more time just
in case.
As to "old cheap coax" this was supposedly "new expensive good coax"! Or so
the marketing would have me believe!
73
Dan
K0DAN
----- Original Message -----
From: "Jim W7RY" <w7ry@inbox.com>
Cc: <towertalk@contesting.com>
Sent: Monday, June 13, 2011 9:19 PM
Subject: Re: [TowerTalk] BLACKENED BRAID?
> It's most likely the jacket. I've had some old cheap coax that did the
> same
> thing. RG-213 with the non contaminating jacket was to keep the shield
> from
> decaying. As well as the center dielectric.
>
> 73
> Jim W7RY
>
>
> --------------------------------------------------
> From: "Al Kozakiewicz" <akozak@hourglass.com>
> Sent: Monday, June 13, 2011 5:46 PM
> To: "'K0DAN'" <k0dan@comcast.net>
> Cc: <towertalk@contesting.com>
> Subject: Re: [TowerTalk] BLACKENED BRAID?
>
>> Maybe it's the soil ph or something...
>>
>> I've taken to using black PVC water pipe. It's cheap and is almost as
>> easily buried as coax. I jump on a flat bladed shovel to sink it full
>> depth; yank the shovel back to expose a crevass; shove the PVC pie in
>> place and drive the 4x4 over the top to relevel the grass. In a few
>> months the damage has disappeared.
>>
>> That way replacing the coax is easy if it's ever needed.
>>
>> Al
>> AB2ZY
>>
>> -----Original Message-----
>> From: K0DAN [mailto:k0dan@comcast.net]
>> Sent: Monday, June 13, 2011 8:38 PM
>> To: Al Kozakiewicz
>> Cc: towertalk@contesting.com
>> Subject: Re: [TowerTalk] BLACKENED BRAID?
>>
>> Hmmm...interesting. We too have the invisible dog fence, and I have
>> something like 100' of 14 or 16 gauge insulated household wiring as the
>> buried loop. Have not had any occasions to dig it up or splice, but what
>> you describe is what I see on the shield of my sliced RG213/U.
>> Interestingly, the center strand (twisted) is OK but the shield is
>> gnarly.
>>
>> As suggested by others I'm gonna pull it back til I find clean copper,
>> but
>> I have a feeling the whole run is gonna have to be replaced.
>>
>> So much for "Mil Spec" and "direct burial". Caveat Emptor.
>>
>> 73
>>
>> Dan
>> K0DAN
>>
>>
>> ----- Original Message -----
>> From: "Al Kozakiewicz" <akozak@hourglass.com>
>> To: "'K0DAN'" <k0dan@comcast.net>; "K8RI on TT"
>> <k8ri-on-towertalk@tm.net>
>> Cc: <towertalk@contesting.com>
>> Sent: Monday, June 13, 2011 7:27 PM
>> Subject: RE: [TowerTalk] BLACKENED BRAID?
>>
>>
>> FWIW, we've always had one of those invisible dog fences. The antenna
>> system for those is basically a loop of insulated #14 AWG wire shoved
>> into
>> a
>> slit in the lawn cut with an edger.
>>
>> Early in their lifecycle they are prone to damage from the lawn mower
>> when
>> frost heaves or whatever expose a section. That wire is always black
>> under
>> the insulation after only a year of burial and is a bitch to get clean
>> enough to solder.
>>
>> Al
>> AB2ZY
>>
>> -----Original Message-----
>> From: towertalk-bounces@contesting.com
>> [mailto:towertalk-bounces@contesting.com] On Behalf Of K0DAN
>> Sent: Monday, June 13, 2011 8:01 PM
>> To: K8RI on TT
>> Cc: towertalk@contesting.com
>> Subject: Re: [TowerTalk] BLACKENED BRAID?
>>
>> Thanks...will see what we have. I have a vision of peeling the braid all
>> the
>> way back to the hamshack! Could be this "direct burial" stuff really
>> wasn't,
>> and the jacket allowed moisture to get into the shield.
>>
>> 73
>> k0dan
>>
>> ----- Original Message -----
>> From: "K8RI on TT" <k8ri-on-towertalk@tm.net>
>> To: <towertalk@contesting.com>
>> Sent: Monday, June 13, 2011 11:56 AM
>> Subject: Re: [TowerTalk] BLACKENED BRAID?
>>
>>
>>> On 6/13/2011 12:39 PM, K0DAN wrote:
>>>> Seems I saw a post here within the last year that diagnosed the cause
>>>> of
>>>> blackened copper shield?
>>>>
>>>> My case: I have a buried run of Cable Experts RG213/U Mil Spec,
>>>> supposedly
>>>> good for direct burial. It recently got nailed by the lawnmower (thanks
>>>> to
>>>> the XYL!), but there's enough stub left above ground to repair and add
>>>> a
>>>> connector, salvaging the buried run.
>>>>
>>>> I looked at a few of the chopped up pieces and the copper braid is
>>>> BLACK.
>>>> The center conductor looks normal, slightly dull copper color but in
>>>> good
>>>> shape, easily cleaned with steel wool for solder/connector.
>>>>
>>>> I would expect to see some kind of green or brown corrosion, but black?
>>>> Is
>>>> this maybe silver plate braid and I'm seeing silver oxidation? Web site
>>>> says
>>>> it's copper, not silver.
>>>
>>> IIRC Copper Oxide is black. Sulfide (fertilizers and atmospheric crap
>>> are *usually*green). Water varies depending on what's in it.
>>>
>>> Cut the jacket back until the braid is clean and shiny copper. Oxide is
>>> a bear to try and solder. Don't let water get in there. If you can't
>>> fix it right away, seal it thoroughly.
>>>
>>> 73
>>>
>>> Roger (K8RI)
>>>> The cable otherwise looks in decent shape, and I do not believe it
>>>> burned
>>>> due to high SWR or lightning.
>>>>
>>>> I don't really want to replace the whole run but don't know the cause
>>>> or
>>>> extent of the blackened braid. I have doubts I can clean it up and make
>>>> decent electrical connections but am willing to try.
>>>>
>>>> RF loss is not an issue, any antennas on this line will be below 7 Mhz.
>>>>
>>>> Ideas?
>>>>
>>>> Tnx es 73
>>>>
>>>> Dan
>>>> K0DAN
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>>
>>>>
>>>>
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>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>>
>>>
>>>
>>> _______________________________________________
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