[Antennaware] Question

Joe Reisert W1JR at arrl.net
Fri Oct 31 13:53:53 EST 2003

Mike etal,

Sealing an RF coax connector is a constant problem. When I moved to New 
England (from San Jose) in 1974, everyone up here said "get some silicon 
grease (I think they called it DC-4?) and squeeze it into the connector to 
keep out water and then seal the connector with electrical tape.

I did what they recommended but a few years later I started to have 
problems. It turned out that small droplets of water did somehow got in and 
migrated into the silicon grease. Eventually it caused an RF path and I had 
flash overs that blew up the connectors on VHF with moderate power (500 Watts).

What I found out is that (what I think) is the proper technique is to not 
apply the grease inside the connector but instead lightly apply a thin 
layer of silicon grease (the compound you find in a small packet as you 
described) sometimes enclosed with expensive connectors or antennas to the 
connector threads and then apply tape on the outside of the connector to 
seal it. If all goes well, and water intrudes, the grease will usually 
confine it to the threads. A small amount of water inside the connector 
usually doesn't hurt.


Joe W1JR

At 04:02 PM 10/15/2003, Mike Switzer wrote:
>I am getting ready to put up my new tower and antennas (been 20 years since
>I have had a real antenna).  I have used in the past a "filler" to keep
>moisture out of my connectors.  I forget what I used can anyone let me know
>what is advisable.  By the way I have used this on some and not used it on
>others and never noticed any difference.  I worked for Motorola years ago
>and with every installation we got a little packet of "grease" to put in the
>connector.  I don't remember who the manufacturer was.
>k8ze at charter.net
>Antennaware mailing list
>Antennaware at contesting.com

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