Topband: Optimum number of radials for given wire length

[Πανος Δαλάκος]

-----Original Message-----
From: topband-bounces at contesting.com
[mailto:topband-bounces at contesting.com] On Behalf Of
topband-request at contesting.com
Sent: Thursday, August 12, 2010 10:00 PM
To: topband at contesting.com
Subject: Topband Digest, Vol 92, Issue 7

Send Topband mailing list submissions to
	topband at contesting.com

To subscribe or unsubscribe via the World Wide Web, visit
	http://lists.contesting.com/mailman/listinfo/topband
or, via email, send a message with subject or body 'help' to
	topband-request at contesting.com

You can reach the person managing the list at
	topband-owner at contesting.com

When replying, please edit your Subject line so it is more specific
than "Re: Contents of Topband digest..."


Hi Frank
I have the ARRL's ANTENNA BOOK 20th Edition, and on Chapter 3 (The
Effects of the Earth), p.3-10 is Table 1 tht maybe contains all you want
about that.
If you haven't the book here is the table:

Number of radials                   16    24     36    60    90    120

Length of each radial in           0.10  0.125  0.15  0.20  0.25   0.40
wavelengths

Spacing of radials in degrees      22.5   15     10     6     4     3
     
Total length of radial wire        1.6     3     5.4    12   22.5   48
installed in wavelengths

Power loss in dB at low angles      3      2     1.5    1    0.5    0*

with a L/4 radiating element

Feed-point impedance in ohms       52     46      43    40    37    35
with a L/4 radiating element

* compared to a perfectly conducting ground

73 Panos SV1GRD