[TowerTalk] Coax joint weather sealing

[Martin Sole]

Many thanks for all the useful thoughts on weather sealing, I learned a 
few things too.

Martin, HS0ZED

>> Martin Sole hs0zed wrote:
>>
>> Thought I would ask here to see if I can get some ideas for system
>> upgrades.
>>
>> Disclaimer: I am involved in a project professionally though I take a
>> lot of this into my amateur radio activities and I'm sure others do
>> likewise.
>>
>> So I have been tasked to provide actual measured data from a lot of
>> feeders where they terminate to antenna tails. Feeders are typically
>> 30-120m runs of AVA5-50, 6-50 and 7-50. Terminations are all DIN7-16
>> typically to FSJ4-50.
>>
>> Every outside connector has been sealed and for the most part there
>> has been no moisture ingress or other failure in more than 90% of the
>> feeders tested. One or two had a nice drip drip but I don't
>> necessarily attribute it to the particular joint sealing.
>>
>> My pain, and really it is a pain is the evil goo that resides with a
>> joint. I believe the joints have been sealed with a 'traditional'
>> method involving some thick butyl rubber compound directly on the
>> connectors followed by a PVC tape over wrap. The local conditions see
>> typically
>> 30-50 degrees C daytime temperatures and the joints were made maybe 7
>> years ago.
>>
>> In removing the PVC tape I am confronted by a sticky gooey oozing evil
>> mess that sticks to everything and renders working on the joint a
>> positive nightmare. There are no known gloves that can be used as the
>> adhesive qualities of the evil goo pull even the most tightly
>> stretched powdered gloves from fingers in a second.
>>
>> I can't believe this is still being done and I'm sure there are better
>> ways. For years I have wrapped connectors first in a couple of layers
>> of plumbers PTFE thread sealing tape so that once the over wraps have
>> been removed the PTFE tape comes away freely and leaves a nice clean
>> connector joint.
>>
>> Times Microwave has a youtube video showing some other methods. I've
>> used cold shrink and its great, but pricey. The silicone tape and the
>> crush together boots look like a winner as well.
>>
>> https://www.youtube.com/watch?v=QHM5RkXD1is
>>
>> Are there other good ways to make a decent weatherproof seal to a coax
>> joint without having to encounter the black goo in a few years time?
>> What's your favourite sealing method?
>>
>> 73
>> Martin, HS0ZED
>>
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