Jack Painter wrote:

[...]

Jack is absolutely right about grease being non-conductive! It only
keeps air and moisture out of the areas where the metal is already
touching.

The same is true of the special conductive greases - the particles of
metal provide the conductivity, and the grease only serves to seal
around the contact surfaces.

Let's drive a stake through this stupid urban myth. Vaseline (pure soft
petroleum jelly) is a mixture of hydrocarbons, and is a very close
relative of polyethylene, polypropylene, beeswax and other well-known
insulators.

Still don't believe it?

Creak... stomp stomp stomp... medicine cabinet... jar of Vaseline...
stomp stomp stomp... multimeter... 20 megohm range... test prods... WELL
OF COURSE it's bloody non-conductive!!!!!

Two touching greased surfaces still read 20M until you grind them
together and force the grease out. And unless you DO force two greased
metal surfaces together, they will be almost perfectly insulated from
each other!

[...]

Just one further comment on Jack's posting:

Because all transmitter antenna radials automatically become a part of
the lightning protection system, the materials used should be the best
you could afford, not the cheapest you can find. And the connections
should likewise be the best possible.

In principle that is correct, but heavy-duty radials are not
cost-effective for ham installations, because there are so many of them
(even in a small system). Also, heavy-duty radials are not necessary for
the main purpose, which is RF grounding for normal operation. For a ham
installation, it seems much more realistic to install enough ground rods
to qualify as a lightning ground in their own right (as if there weren't
any radials at all). Then you can treat the radials as being purely for
RF grounding. They will of course contribute to lightning grounding, but
you don't have to rely on them for that purpose.

We're moving house, so I am just about to tear up the radial system here
- and also pull out the 8ft ground rod that goes 5-6ft into groundwater.
The next QTH will have much more space, so this discussion comes at just
the right time.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek