Dielectric grease (aka Silicone grease) is non-conductive. The idea is that it prevents corrosion and does not break-down rubber parts (like spark-plug boots) You generally do not want to put it on contacts, but contacts with pressure will be significant to push though the grease. The greases with a conductive metal powder are to overcome the non-conductive properties of the grease. An antenna would be a perfect example of this use, since the grease would prevent the corrosion that would make it hard to take the pieces apart, and the metal powder would allow metal to metal contact as the parts were connected together. 

If you are looking to enhance the conduction at the connector level, you would be better off to use a product like Deoxit on the conductors (like spade connectors) and if worried about corrosion put the grease around the outside of the connection. 

Does that clear things up? It can be confusing because there are some sources on the internet that imply that dielectric grease is conductive, which it is not. 
Here is a pretty good post that tries to clear up some of the misinformation: 
http://www.w8ji.com/dielectric_grease_vs_conductive_grease.htm 

Todd 

----- Original Message -----

From: "Chris S." <szpejankowski@GMAIL.COM> 
To: vanagon@GERRY.VANAGON.COM 
Sent: Friday, March 7, 2014 10:07:04 AM 
Subject: Re: Dielectric Grease 

Dielectric is non-conductive. The stuff you're describing sounds like a contact enhancer and oxidation preventative. I'm no expert, so it's more of an inquiry than a statement. 

Chris. 

Wysłane z iPhone'a 

Dnia Mar 7, 2014 o godz. 12:00 John Collins <oldguyflier@YAHOO.COM> napisał(a): 

> I have used a grease loaded with copper powder on radio antenna connections topside on my cruising sailboat. It blocked all corrosion about six feet above salt water and made a perfect connection. I covered it with rubber tape just to keep from getting it on my clothes. Bought it at an amateur radio store. 
> 
> John Collins 
> S/V PRIMO (Panama) 
> 
> Sent from my tiny piece of magic glass