I said flooded a few sentences later. It appears that you (by inference)
use flooded everywhere outdoors.
I have gone over to flooded + PE jacket for all my RX cables for the last
three years, including TV AND indoors and DO NOT use anything else. The PE
jacket lets me know what kind it is, since all the PE jacket stuff I have
bought is flooded, and any involved cables not of the flooded/PE variety
get replaced. Given that the only open end on my failed TV stuff was in
the house, and all the external clearly in undiminished possession of it's
original sealing, apparently just the moisture in the house is enough to
take down some of the "RG6" varieties.
It IS clear that NON-flooded foil types can go bad with disintegration of
the foil. The point would be just how effective is that heavily oxidized
and brittle shield in actually keeping common mode or heavy induction off
the center conductor.
I would presume you have had no chance to measure shield penetration in
that flawed disintegrated situation because you are and have been for a
long time using the "good stuff".
I try to always put "RG6" in quotes now. However technically incorrect,
the "RG6" has become almost universal common usage, used as the name for
the general type of cable. This linguistic inertia will overwhelm attempts
to get to "technical correctness" by many orders of magnitude. I have
found that if I don't use "RG6" AND the correct nomenclature in
correspondence, that folks on the other end just get confused. They
understand it when I describe the cable as XXXXXX in the family "RG6"
types. Repeat the serenity prayer and move on. Better things to worry
about that I have a chance of changing.
In the end the cheep "RG6" stuff is more expensive and the apparent short
cut is miles longer. We spend hours and hours figuring our next purchase
of a rig, amplifiers to the last 1/10 of a dB, and go cheep on antenna
stuff. Go figure.
73, Guy
On Thu, Jun 21, 2012 at 12:21 PM, Tom W8JI <w8ji@w8ji.com> wrote:
> > I have recently replaced some "RG-6" in use for maybe seven or eight
> > years.
> > I opened it up to see what was happening. The degree of oxidation on
> the
> > inside and outside of the foil was perplexing. One could easily draw a
> > thumbnail along either side and build up a little pile of oxide. The
> foil
> > itself had become very brittle. It had been "sealed" and treated
> outside.
>
> Use flooded cable outside.
>
> > If Jim says the shielding needs help when it's new, there's not much hope
> > for some varieties when it gets old. Another reason not to use anything
> > other than the flooded variety. Particularly so for someone who can look
> > at the ocean. I'm hundreds of miles from salt air. Would need to go
> with
> > flooded for sure close to the ocean.
>
> CATV F-6 or F59 cables are great for 160, or any HF band use. I use ten's
> of
> thousands of feet of the stuff, much of which has been installed in the
> early 2000's.
>
> My trunk cables are primarily flooded hardline, stepping down to F-11 style
> (F does NOT mean flooded, it is for F connectors) flooded cables for
> distribution, although some F-11 runs are thousands of feet. The longest
> run
> of F11 is about 3000 feet, and it is dead quiet when terminated.
>
> I have measurements on my webpage of F11 excited by overhead dipoles, and I
> can say with 100% certainty any claims of meaningful shield leakage are
> simply not factual.
>
> The same is true of smaller F6 cables.
>
> The only potential worriesome issues I have seen are lightning melting
> shields. This happens when ground loops create large strike currents in the
> shields. For example, when my towers get a hard whack from a superbolt, the
> common mode current can follow trunks out to my vertical array. That array
> has eight 150-foot buried radials on each of eight elements, and currents
> that massive wide-area ground will occasionally melt a shield on F-6
> cables.
>
> Other than that, Racoons, and mowers, F6 through F11 has been flawless.
> This
> is true in working systems and in actual measurements.
>
> 73 Tom
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
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