Topband: insulated vs:bare radial wires

[Gene Smar]

Jim:

     Insulated wire is more durable than bare in radial applications.  The 
soil pH is kept away from the (presumed) copper wire inside the insulation 
so the wire will last longer in all soil types than will bare wire. 
Insulated wire is also more resistant to mechanical nicks that occur due to 
frost heave moving rocks against the wire.

     As for the velocity factor thing, forget it.  Once the wire, bare or 
otherwise, is in contact with earth, the capacitance of the wire to earth 
swamps out any transmission line features of the wire.  So you can even 
shorten the radials and add more of them.  The amount of earth you cover 
with wire is the key to planting a successful radial garden on Topband.  Of 
course, if you have that much wire available, then by all means use long 
radials.

73 de
Gene Smar  AD3F


----- Original Message ----- 
From: "Jim Hoge" <knowkode at sbcglobal.net>
To: "topband reflector" <topband at contesting.com>
Sent: Wednesday, December 02, 2009 11:08 AM
Subject: Topband: insulated vs:bare radial wires


Greetings,

Can I expect any noticable difference using an insulated wire for radials? 
Theoretically, the velocity factor of the insulation will make the physical 
length shorter but is a tuned 1/4 wave radial length that important when it 
is buried or laid on ground? The plan is to use 18ga awb, of which I have 
some 30k feet at my disposal.

tnx,
Jim W5QM
_______________________________________________
160 meters is a serious band, it should be treated with respect. - TF4M