Topband: Vertical in the woods

Tom Rauch w8ji at contesting.com
Sun Oct 12 12:04:04 EDT 2003


Tim,

I don't think any reliable information documented anywhere could ever answer
your questions with hard data. Information on effects of trees on low bands
has been impossible to find. I wouldn't think it to be a major issue, and
the height of ground certainly doesn't matter much. I'd put the antenna
where it is easiest to install (since that also is the clearest area) and
not worry.

>From BC experience I can tell you the voltage and current in a few radials
of any type is very high, and enough to be hazardous. The smaller the radial
system is, the more concentrated the fields are and the higher voltage and
current becomes. The greatly increasing loss that occurs as radials are made
shorter or fewer in number is a direct result of the fields around the
radials increasing. This happens because voltage and current are higher in
each radial with short or small radial systems.

This is why small radial systems, despite claims to the contrary, are
problems in many aspects....not just antenna efficiency.

If you used 40 or more reasonable length radials, the voltage and current in
each would be reasonable and you would not likely have a problem with a
hazard like fire or electrical shock or burns.

73 Tom




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