[TowerTalk] PL259's and heat shrink tubing

Pete Michaelis - N8TR pete.n8tr at gmail.com
Wed Jul 15 11:46:19 PDT 2009

I use the procedures described below by W9FX to seal splices with the
exception of step 1 which I leave out.  I find that the Scotch 130C
conforms to the connector better than Scotch 33+ or the Scotch 88+
that I mostly use and it is quite easy to remove.  With a few knife slits it
peels right off.  I just opened one today after being outside for several
years. When I peeled off the Scotch 130C you could read the lettering
(backwards) on the connector imprinted on the fused 130C.  It was
not at all gooey.

Using these procedures  connectors remain bright and shiny even after
being up on the tower for more than 10 years.

73 Pete - N8TR

At 09:13 AM 7/15/2009, W9FX wrote:
>A few decades of experience at waterproofing damaged and spliced trailing
>cables in underground mines yields the following methodology:
>1.  Wrap the area to be waterproofed with two layers of Scotch 33+.  Start
>in the middle of the area to be covered.  Wrap to one end of the connector,
>then, reverse the pitch of your spiral wrap and, without breaking the tape,
>wrap to the other end.  Reverse the pitch again and finish back where you
>started, in the middle of the connector.  This method leaves only one end of
>the 33+ exposed - reducing the chance of unravelling from adhesive failure
>(and, wind teasing) by 50%.
>2.  Apply 3M type 130C self vulcanizing tape.  Stretch the tape to 50% of
>it's original width when applying, and, apply the tape with the 'sticky'
>side up, which is counterintuitive.  Each wrap of the tape should overlap
>the preceding wrap by 50%.  As before, start in center of the connector,
>work to one end, reverse, then, back to the center.
>3.  Cover the entire area - plus a little overlap (1/2" to 3/4") on each
>end - with 33+ per step 1, above.
>The initial layer of 33+ ensures that, should you ever need to open the
>connection, you can do so without having to fight with a gooey, vulcanized
>mess.  The initial layer of 33+ will allow you to cut the the various tape
>layers away cleanly.  The top coating of vinyl tape is for abrasion
>resistance, and, to protect the soft 130C tape from sun and wind.
>If this is done correctly, the connector will withstand many years of
>weather.  Scotch 130C is available from a variety of sources, and, while it
>can be pricey, in my opinion it's worth the extra $.  The option, having to
>replace a water-soaked feedline, is even more costly, tower-climbing labor
>and aggravation notwithstanding.
>We tried shrink tubes - both hot (flooded) and cold - for a few years.  None
>of those schemes provided the safety (of workers) and protection (of the
>cables) afforded by the foregoing method.   If repairs had to be made to
>shrink-tube protected areas of the cable, removal of the shrink tubes wasn't
>an option.
>73, Brad, W9FX
>TowerTalk mailing list
>TowerTalk at contesting.com

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