[TowerTalk] Monoband Yagi stacking heights

[n4kg@juno.com]

I would recommend a 2L40 at 85 ft,
and tribanders at 35 to 40 ft and 60 to 70 ft.

My 80 ft high high-band antennas play well 
at night but get creamed by my LOWER
antennas during the day.  

40M antennas play VERY well at 80 to 100 ft.

Remember, most of the DX stations are using
LOW antennas SO, when the ionosphere will
support higher angles (i.e. during the day),
higher angles may produce greater signal strength
than low angles because your peak angle
is matched to the peak angle of the DX.

Coverage of high angles drops off 3 degrees
for each 1 degree you pick up with increasing
height which means that the higher you go
the LESS coverage you have.  For the really
low angles, I like 120 ft for the high bands.
At this height, the SECOND lobe is also
at useful waveangles for daytime propagation.
Fill in the hole with another antenna at 40 to 60 ft.

de  Tom  N4KG  (with 8 high band antennas on 7 towers)




On Sun, 1 Oct 2000 11:38:04 -0700 "Al Williams" <alwilliams@olywa.net>
writes:
> 
> This is a timely subject for me as I plan to install them at 85' and 
> 53'
> (70' tower + 15' mast and highest overlap section of crankup).  I 
> have never
> had a yagi higher than 45' (TA33) so no experience but a lot of 
> reading and
> EZNEC modeling.
> 
> There seems to be a difference between what EZNEC and antenna books 
> say and
> what Towetalk postings most often say.  The postings usually have 
> specific
> heights in feet and desired communication destination, most often 
> Europe and
> the Caribbean/South America.  The books and EZNEC usually reference
> wavelength height (frequency) and elevation angle (from which path 
> hop
> distance can be determined).
> 
> Because higher yagis have multiple elevation lobes at the higher
> frequencies, I would think that the heights should be selected so as 
> not to
> duplicate the elevation angle lobes if one wants to spread the 
> distance
> path.  On the other hand, the heights should be (?) selected to 
> duplicate
> the elevation lobes if maximum gain is desired at the expense of not
> spreading the distance path.
> 
> Further, I suspect that optimum antenna heights for Sweepstakes 
> activity
> from Midwest locations would be different than from coastal 
> locations
> whereas the optimum height for
> worldwide paths may not be so different.
> 
> I have selected 85' and 53' not because of analysis but rather it 
> "fits" the
> 70' crankup tower. I am planning to be able to switch to use U/L/B 
> and am
> hoping for a significant improvement from my previous trapped TA33 
> at 45'.
> Comments will be appreciated
> 
> k7puc
> 
> 
> 

________________________________________________________________
YOU'RE PAYING TOO MUCH FOR THE INTERNET!
Juno now offers FREE Internet Access!
Try it today - there's no risk!  For your FREE software, visit:
http://dl.www.juno.com/get/tagj.

--
FAQ on WWW:               http://www.contesting.com/FAQ/towertalk
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com