Topband: Fw: 25G insulators

Harold Smith price.smith at worldnet.att.net
Sat Aug 30 19:18:24 EDT 2003


Pete:

I believe that this has been discussed by PolyPhaser in their book on
grounding. Very high voltages will be induced in all conductors on the
tower, they are like a secondary of a transformer. The tower is the primary.
No tower is zero ohms from top to bottom, other wise it would be a
superconductor. (Yes, I have dealt with superconductors used in MRI medical
scanners.) Several thousand amps flowing thru a fraction of an ohm is
produced by a multi kVolt lightning strike. It doesn't matter to the
lightning if the tower is grounded or not. At that voltage the lightning
doesn't care.

On insulating the tower: Wolf DF2PY has several huge crankup towers that he
insulated with fiber-glass blocks. It is very difficult to shunt feed a
large (huge) crankup tower. Very impressive. I have some pictures that I
took a couple of years ago when I was there that I will email to anyone
interested.

73 de Price WØRI, Club trustee of WØCKC


> and rotator position pots the same.  Isn't it reasonable to assume that
any
> time a tower, whether grounded or not, takes a direct strike, it is likely
> that destructive voltages will be induced in any conductors on the tower?
>
>
> 73, Pete N4ZR



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