H John,
I always follow the ARRL Antenna Book info:
----------------------------
Practical Suggestions For Vertical Ground Systems
At least 16 radials should be used if at all possible.
Experimental measurements and calculations show that with
this number, the loss resistance decreases the antenna efficiency
by 30% to 50% for a 0.25 wavelength vertical, depending on
soil characteristics. In general, a large number of radials (even
though some or all of them must be short) is preferable to a
few long radials for a vertical antenna mounted on the ground.
The conductor size is relatively unimportant as mentioned
before: #12 to #22 copper wire is suitable.
a.. If you install only 16 radials they
need not be very long - 0.1 lambda is sufficient.
b.. If you have the wire, the space and the patience to lay
down 120 radials (optimal configuration), they should
be 0.4 lambda long. This radial system will gain about 3 dB
over the 16-radial case.
c.. If you install 36 radials that are 0.15 lambda long, you will
lose 1.5 dB compared to optimal configuration.
----------------------------
Based on this, and at four radials/band, the longest four should be 80 x
0.15 = 12 meters. Better would be all 36 at 12 M.
73 -- Larry -- W1DYJ
-----Original Message-----
From: Charles Morrison
Sent: Wednesday, August 22, 2018 11:51
To: W1JCW John
Cc: towertalk@contesting.com
Subject: Re: [TowerTalk] Number of Radials and what lengths vertical 80m up.
I think the manual says four radials per band
On Wed, Aug 22, 2018 at 11:50 AM W1JCW John <W1JCW@hotmail.com> wrote:
Putting a steppIR Big IR 80m - 6m.
What length of radials should I put on and what lengths?
Have room for several and wanted to see a few schools of thought of
lengths and how many.
Thanks
73-
W1JCW
John
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