Topband: Radials - a point to ponder

[Michael G. Carper]

When I sent out a recent email about the 160m inverted-L I was finishing
with four ¼ wavelength (130’) radials, I got a few responses back indicating
that I should cut them in half and double them.

 

So I got out ON4UN’s book to look at the guidance there.

 

·         Chart 9-18 on p. 9-12 indicate that the radial lengths should be
10m, 40m, and 80m (basically, that’s 32’, 130’, and 260’ w/rounding).
There’s no mention of 20m (65’) radials in these models.

·         Table 9.3 on p 9-14 indicate that for four radials, the optimum
length is 0.10 wavelength (about 51’) and 0.15 wavelength (about 76’) for
twelve radials.

·         Then again, the text in section 2.1.3 on p 9-14 says “on 160
meters, you should use 20-meter (65’) radials if you are only using a few
(up to four).

 

Overall, I’m considering going with the design suggestions in table 9-3 for
twelve radials (30-degrees apart) that are 76.7’ long (0.15 wavelength for
1.83 Mhz).

 

Any opinions about that?

 

Mike, WA9PIE