[TowerTalk] FCP vs On ground.txt

[Joe Subich, W4TV]

On 2022-01-21 3:56 PM, Jeff Blaine wrote:> The argument in support of 
using high elevated radials is not
> supported by the N6LF data.  In fact the data Rudy has says even a
> slight elevation from ground gets you most of the way there with
> respect to loss.
I don't believe N6LF has done any work with elevated radials at 0.05
wavelength or greater above ground.  20 years (or more) ago N7CL
reported on work done by the US military which spoke to "elevated
ground planes".  That work started from even greater heights but
showed that the losses started to increase dramatically at 0.05
wavelengths.

73,

    ... Joe, W4TV


On 2022-01-21 3:56 PM, Jeff Blaine wrote:
> The argument in support of using high elevated radials is not supported 
> by the N6LF data.  In fact the data Rudy has says even a slight 
> elevation from ground gets you most of the way there with respect to loss.
> 
> When I build my prior 80/160 dual band vertical, the length of the 
> radials, the count of the radials, and the height above ground decisions 
> were all pulled directly off of the N6LF QEX article series.  Rudy has 
> done all the hard work and while it's a serious set of articles, the 
> answers on the trade offs for these things under discussion are all 
> there in his article.
> 
> It worked great until we had a "wind event" which turned it into scrap - 
> but that had nothing to do with the radials.  ha ha
> 
> Now the applicability of the single vertical as it would be extended to 
> the specific case of a 4-square is less well researched.  I'm unaware of 
> any published serious 4-square modeling studies with various elevated 
> radial permutations.  Then again a 4SQ is pretty forgiving for a lot of 
> reasons and my opinion is that just about any version of a 4SQ, no 
> matter how big of a mess, probably will run circles around even the 
> perfectly built vertical.  But I'm sure that's not true in the absolute 
> sense.
> 
> 73/jeff/ac0c
> alpha-charlie-zero-charlie
> www.ac0c.com
> 
> 
> On 1/21/22 2:43 PM, Chuck Dietz wrote:
>> I have been following this thread closely because I am planning a 4 
>> square
>> and thinking of the single, elevated radial from each vertical. For 
>> 160m I
>> was thinking of a quarter wave radial from the bottom of each vertical at
>> about 25’ sloping down to about 10’ at the end. But I guess that 
>> should be
>> in a new thread.
>>
>> Chuck W5PR
>>
>> On Fri, Jan 21, 2022 at 1:48 PM Jim Brown <jim at audiosystemsgroup.com> 
>> wrote:
>>
>>> On 1/21/2022 11:19 AM, David Gilbert wrote:
>>>> Thankfully for any of us that actually consider ham radio to be a
>>>> technical hobby instead of just a wireless chat room, not everyone here
>>>> shares your perspective.
>>> YES!  Much of the ARRL Handbook is tutorial material. Indeed, I'd wager
>>> that most if not all of the teams that have put us in space first
>>> learned electronics and radio from the Handbook.
>>>
>>> And most of what I post online is aimed at helping folks learn. The
>>> disappointing thing is when I do that, questioners seem to post new
>>> questions suggesting they didn't bother to study either what I (or
>>> others) had written on the reflector, or what I'd posted links to on my
>>> website, some of which I'd spent weeks or months learning and writing
>>> about.
>>>
>>> 73, Jim K9YC