I have a mostly similar background and experience, 2way radio and silicone
grease, except, they learned. At 400 mhz and higher, flooding an N
connector with silicone greade (dow #4) introduces a significant and reasonably
easily measured impedance bump. For the last couple of decades the Andrew
connector and antenna installation procedures specifically caution against
getting the provided grease on the inside of the connector, and they privide
superior methods of sealing a connector, significantly more elaborate than
most would choose to bother with for Topband , especially in small connectors
I also subscribe to the philosophy that its better to have a small impedance
bump than even a tiny amount of moisture ingress.
At Topband, silicone grease flooding any connector potentially subject to
moisture ingress is far superior to fixing water damage, and has zero risk of
arc or flash over path.
It remains best to seal all connectors so water CAN NOT get in in the first
place.
For conventional connectors, from typeF through UHF and N to DIN, shrink boot
the back of each connector, atttach them to spec tightness, then a single
TIGHT layer of regular tape (33 class) then wrap with a liberal layer of thick
sealant like coax seal, be sure to extend it out to the cable jacket on both
sides, then a layer or two of tape to hold the sealant in place and protect it
from its environment,
That will not leak. If water gets inside, it will have wicked down the
inside of the coax from a broken point in the jacket (which is why you want to
use flooded RG6, and direct burial rated cable)
Make your own variations, but this process is what is currently recommended
for heliax and foam/braid cables by the manufacturers
Robin, WA6CDR
-------- Original message --------
From: Bill and Liz <magoo@isp.ca>
Date:11/25/2013 04:45 (GMT-08:00)
To: topband@contesting.com
Subject: Topband: CONNECTOR GREASE
When I first got into the 2-way radio business back in the 70s I obtained a
lot of literature from both Motorola and General Electric, for whom I did
sub-contract work. On the subject of installing base station antennas, both
companies recommended that the connectors be flooded with "vaseline" before
being sealed.
Routine yearly maintenance testing showed no change in antenna system
operation over the years, and when I had occasion to remove some of these
antennas many years later there was no evidence of any problem with the
connections.
Granted, these base stations and repeaters operating in the VHF and UHF
range ran at no more than 100 watts; however, if one were to expect a
problem by flooding a connector with "vaseline" then surely it would have
shown up at these frequencies.
I guess you can take advice from any source you wish on this, but I doubt
that reputable organizations like those cited above would have recommended
flooding with a petroleum-based substance if they thought the practice would
cause problems down the road.
Bill VE3CSK
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