Topband: CONNECTOR GREASE

[wb6tza]

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 at isp.ca> 
Date:11/25/2013  04:45  (GMT-08:00) 
To: topband at 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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