http://elecraft.85.s1.nabble.com/Inverted-L-was-OT-Vertical-antenna-tp5852957p5854632.html
> Dave,
>
> If you read the radial tuning procedure in Low-Band DXing, you will find
> that it "all comes out in the wash". Yes, your statements are correct,
> and in fact that is how I did mine. Although I did not resonate my
> vertical monopole against any ground plane - I simply cut the lengths to
> what was stated in the article, and then cut each radial to resonate
> with that particular length of the "monopole". If the result was
> slightly "off-center fed", so be it, the impedance and the resonance
> point obtained were a good match for 50 ohm coax, and I left it at that.
>
> OK, so the ideal impedance of a vertical antenna is 32 ohms - I got
> closer to 50 ohms which indicates a 15 ohm loss in signal efficiency.
> It matches my feedline nicely, and I an willing to accept the the 3%
> loss in efficiency that represents.
>
> The ground conductivity in my area is not the greatest, so I have
> accepted the logical consequences of that fact.
>
> 73,
> Don W3FPR
>
>
> On 12/20/2010 8:06 PM, David Gilbert wrote:
>> "I personally would not consider elevated radials that are non-resonant"
>>
>>
>> I guess I'm having a difficult time with that comment. You can have a
>> resonant system without the elevated radials themselves being
>> "resonant" ... i.e, any two of them acting like a resonant dipole. If
>> the elevated radials are shorter than a 1/4 wavelength, all that is
>> required is that the vertical section be a little longer than a 1/4
>> wavelength to compensate. If the radials are longer than a 1/4
>> wavelength, the vertical section needs to be shorter than a 1/4
>> wavelength for resonance.
>>
>> Elevated radials are kind of like the lower half of a vertical 1/2
>> wavelength dipole except that it is "fanned out" for symmetry, and if
>> the radials are longer or shorter than half of a 1/2 wavelength dipole
>> the feedpoint simply behaves similarly to an off-center fed dipole. You
>> can prove this to yourself with EZNEC ... start with a vertical section
>> longer than 1/4 wavelength and see what length radials you need to have
>> a resonant feedpoint. Then do the same thing with different lengths of
>> vertical sections and see the effect on radiation pattern. I can tell
>> you that it isn't a direct function of radial resonance.
>>
>> I could be wrong, but I don't see any need at all for the radials to be
>> "resonant" on their own. You want system resonance and generally
>> speaking, for radiation effectiveness you want as long a vertical
>> section as you can manage. You might want to choose a vertical section
>> somewhat longer than a 1/4 wavelength and radials correspondingly
>> shorter than a 1/4 wavelength in order to take advantage of that
>> "off-center feed" aspect I mentioned in order to get a 50 ohm match.
>>
>> The only situation where resonant radials might be required is if you're
>> trying to decouple whatever is on the other side of the radials. In
>> that case, the radials act like a choke to keep current on the feedpoint
>> side of the resonant radials. You can see that effect with EZNEC as well.
>>
>> 73,
>> Dave AB7E
>>
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