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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