[PVRCNC] Optimum # radials article

[wlbaber at bellsouth.net]

How many radials?  After an initial 16 on one 160 meter "T"
vertical 3 years ago, I added a second T vertical and phased it with
the first one, and since then I have added radials each of two year,
and usually about this time (my third year).  In the meantime, I
look for cheap wire, and repair radials cut by the lawn mower!  I
don't ask that question any more (how many radials?).


Another way to go is elevated radials.  I use 6 of them on each
element of an 80 meter four square, which I am renovating according to
the admonishments of antenna Guru, Guy, K2AV.  BTW, anyone over 6
foot tall must not run in my back yard.


I had each element extended by, and clamped to, the support ropes off
the 90 foot point of the tower.  I'm in the process of cutting the
ropes so that the top-hat loading wires are suspended in space with
rope attached to both ends.  Also, I'm uing ladder line instead of
a single wire element  in the same T type configuration, but at
the angle of the ropes.  It became clear to me from 160 meter
success that ladder line carries more current and as a result there is
higher efficiency compared to a single wire element, as in the typical
inverted L.   I'll see if the same results occur on 80 meters in
CQWW!  


For 160 meters I need a regular high dipole to work locals before 160
meters goes long.  The T verticals are not as good as a beverage
but if you don't have room for a full-size beverage you will appreciate
a T vertical.


Anyway, the point is:  adding radials comes under "there is always
something to fix."  I noted loss of  one element of a T
vertical used as an 80 meter antenna during
SSCW...I knew it in the first 15 minutes of switching to 80 meters for
the run! 
After that I could relax, the competitive part of the contest was over,
early!


73, Will, wj9b, dit dit

Once PVRC, always PVRC


 



 -------------- Original message from mike at bentwire.net: --------------


> After Ken's presentation, I got to thinking about implementing his
> suggestion of a tight mesh in close to the vertical feedpoint. Wire
> mesh fencing would seem ideal. Except all of that stuff is galvanized
> steel - Low conductivity, difficult to establish a solid electrical
> connection to. Not to mention the eventual rust issue.
> 
> Any suggestions for a) aluminum mesh fencing source or b) ways of
> solidly connecting to galvanized mesh?
> 
> I believe b) has more practical potential. I'm thinking some sort of
> clamp with lotsa alumilox or equivalent.
> 
> Of course, once I win the lottree, I'm installing copper sheeting in
> the back forty.
> 
> Mike/N4GU
> 
> 
> 
> "Kent Winrich"  wrote:
> 
> 
> Note: Forwarded Email Message Below:
> 
> 
> 
> You can play with burying hundreds of feet of wire or you can go elevated:
> http://www.nottltd.com/ElevatedRadialSystem.pdf
> 
> As I mentioned in my presentation, it is most important to cover an area
> close in to the antenna.  There is not a big addition in coverage with the
> longer wires.  It is better (if you go buried) to have MORE then LONGER
> radials.  I suggested a 20' square of an interwoven 'grid" with about
> 1 - 2'
> squares to create a "screen" .  Elevate it if you can!
> 
> In this article a number of issues are skipped over (or I read to fast,
> which is quite possible).
> 
> Dont you find it interesting that they are suggesting a LOWER number of
> radials in poor soil?  That is because of ground loss.... something the
> elevated system is supposed to lower.
> 
> Another issues is that they talk about the NUMBER of radials versus
> the area
> covered.  So if I have 500' of wire, they are still suggesting that ALL
> radials be 1/4 wavelength.  Unfortunately they didnt try shorter, but more
> numerous radials.
> 
> BTW in our area, I always assume that we have poor (heh or NO) ground
> conductivity.
> 
> Here is a discussion and data about elevated versus standard ground system
> in Ham Radio Frequencies:
> http://www.arising.com.au/people/Holland/Ralph/shortvert.htm
> 
> Here you will see that 3 -4 elevated wires can out perform 32 buried
> wires!
> 
> Kent Winrich
> K9EZ/4
> b0zo #143. www.ab0zo.com
> Somewheres near Fuquay
> Ex Cheesehead
> Packer Fan and Stock holder!
> 
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