[MVMA] Former 2nd St Water Tank station disassembly: water discovered in filter

[Larry Baker]

That must have been fun!
Epically finding shoddy workmanship and finding the root cause of our problem.

Maybe a shot of flex-seal would have prevented it and should be considered in other installs.

Larry Baker KB8EMD

________________________________
From: mvma-bounces at mailman.qth.net <mvma-bounces at mailman.qth.net> on behalf of Chuck Gelm <nc8q-mesh at gelm.net>
Sent: Thursday, May 10, 2018 7:11:02 PM
To: Amateur Radio network using AREDN, HSMM-MESH and other configurations
Subject: [MVMA] Former 2nd St Water Tank station disassembly: water discovered in filter

2018-05-10:

  I met Tim at his garage workshop and we disassembled and
inspected the former 2nd St Water Tank Omni, filter, and
Bullet(Titanium).

  The Omni was disassembled and its interior appeared pristine.
All RF connectors were shiny and bright inside and out.

  The Bullet was disassembled and its interior appeared pristine.
All RF connectors were shiny and bright inside and out.

  The filter was disassembled and immediately we spotted about
1 - 2 teaspoons of clear liquid which, likely, was water. The cover
was discolored where the bottom is when the system is typically
mounted. The 'N' connectors were pristine, inside and out. We
next removed the 'N' connectors from the circuit board and
lifted the board out of the enclosure. Wetness was discovered
in the enclosure below the circuit board. We noticed that the
grounding fastener was an internal hex nut that was 95%
sealed with silicone rubber. The portion of the hex nut adjacent
to the circuit board did not cover the entire nut-to-enclosure area.
Additionally, the threads of the nut did not match the threads of
the screw. The screw threads were smaller size than the nut
threads. The clearance hole for the grounding screw and nut is on
the side of the enclosure and this is likely where rain water
entered the enclosure.

Chuck nc8q



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