[SMCARA] G5RV antenna installation

[William S Merritt]

It is a bit difficult following your descriptions.

The only operating goal you mentions is "...more of an omnidirectional 
pattern".

-No antenna can do all things on multiple bands.
-The antenna patterns will change significantly from band to band, with 
changes in 'relative' height, i.e. referenced to height in wavelength.

-While performance is greatly affected by proximity to soil, in extreme 
cases of slopes, I would recommend ignoring the slope and reference the 
horizon.

-The closer a Dipole is to the soil, the more the capacitive coupling 
and the more RF losses increase.

-Resonant Dipoles are essentially omnidirectional below 1/2wl above 
ground and do not  achieve a full typical Figure 8 pattern until they 
approach 1 wl.

-Dipoles show increasing omnidirectional pattern as the depart from a 
level plane (Inverted V).

-A single dipole used on multiple bands does NOT have typical Figure 8 
patterns on bands other than the resonant band.   Instead the patterns 
break up into more and more lobes with higher and higher take off angles.

No antenna installation is ideal.  It is all a matter of trade offs.  Do 
the best you can.  73, Bill

On 9/21/2014 1:53 PM, Dave Q wrote:
> All,
>
> I plan to permanently hang my Optimized G5RV dipole tomorrow.
>
> I have three large white oaks almost exactly inline but they are on a
> slope.  If I were to tie a string at ground level of the highest tree and
> run it level to the farthest tree there is an 11' drop crossing the center
> tree at 4 feet.  The center insulator will be at 45' where I already have a
> pulley installed.  I've made stand-offs from 4" PVC pipe by cutting 1"
> rings.  These will be screwed to the tree and the ladder line attached to
> them.  The ends will be attached to the trees with pulleys and homemade
> "window weights" to allow for tree movement, falling branches, ice/snow etc.
>
> I have a 30' extension ladder so should be able to get the ends at
> least/about 20 to 25' off the ground.  The trees lie in an East to West
> orientation.  Would rather it be more N to S but it is what it is.  I will
> be also installing one of the 31' S9s.
>
> Questions:
> Do the ends need to be the same distance from the ground in order to
> maintain the angle of each wire the same?  For instance, can one angle be
> 45 degrees and the other 60 degrees or other combinations?
>
> The instructions say to maintain a an included angle of 160 -170 degrees
> for best performance but I'd like more of an omni directional pattern.
> What angle would you shoot for?
>
> What would you do considering both of the antennas?
>
> Any thoughts and advice greatly appreciated.
>
> 73
> Dave - W3DLQ
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-- 
Bill Merritt
KB4QAA/3