[TowerTalk] Tower heighth question

[K7GCO@aol.com]

In a message dated 06.02.00 13:47:06 Pacific Standard Time, K7GCO writes:

<<  k9mi@hotmail.com
 
    A short boom and other compromises of your antenna results in wider E&H 
Planes which at 40-50' high is just what you need and want to maximize the 
performance of your beam.  At that height the reflection factors are higher 
than we have been told are optimum.  For stateside a lower gain beam will put 
far more RF into an optimum angle than a high gain beam which has a sharper H 
Plane (vertical pattern).  I've pinned S-meters stateside with a 20M yagi 
that had a 96 degree vertical beam width, 1/2 WL high and been accused of 
running many KW.  I've done the same with a 2 element quad with .12 WL boom 
which had a 100 degree vertical beamwidth.  Over a 11 year sun spot cycle you 
will have a stronger average signal with right where it is.  It will still do 
a great job on DX as some have just verified on TT.  
You will gain a few dB on DX with it at 70' or higher but lower your signal 
reports at distances that are usually 90% of all your contacts.  Contesters 
need every low angle dB they can get but it does the most good when the band 
is just opening and closing.  When the DX paths are really open they often 
switch to a lower antenna again and again.  Low angle antennas are on the 
average low percentage of use antennas.  When they are in they take command.
      Your antenna design and investment is best served at 40-50'.  You have 
the least mechanical headaches and guy wires and any maintenance is always 
easier, more often on the higher towers.  Are you handy on the tower?  Self 
supporting towers are often used and is such a blessing and favored by XYL's 
and neighbors.  My tower is 40' with a 5' heavy mast and a 20' telescoping 
addition.  If I can hear it I can work it.  I can do any maintenance on any 
weather.
       Now when you are in the chips and have the land for 100' tower and guy 
wires, install a higher gain mono-bander 70-100' which will utilize it's 
sharper vertical pattern fully.  You will even hear DX you may not even hear 
on the lower beam.  With selected use and when the novelty wear off, you will 
still be using the lower beam a much higher % of the time.  In the low sun 
spot cycle it will get little use and your investment in a few dB's is 
seriously minimized.  The cost of a few DX dB's is not justified for those 
who are on tight budgets.  Unfortuntaly our extra expensive dB's also go off 
into space to never be heard again.  If I shoot a more expensive magnum rifle 
which I have and use far less than the standard rifles and with only a 
fraction of a dB higher velocity--it goes off a little further into space and 
I'll never see it again.  If I make a bigger enlargement in photography I put 
it on the wall and can observe it until I die.  There is a difference in how 
we spend our money on hobbies.  It pains me when I think of it over my 
lifetime.
       It's time for a complete mechanical overhaul of your beam to justify 
it's use now.  Clean all the joints and coat with Anti-Seize with aluminum 
particles.  Evaluate it's performance now and you may forget a 70' tower.  Or 
install a 5 band 2 element quad (I even added 6M) with only one soldered 
joint per element that never needs cleaning.  It should be a design with 
individual fed DE's from a coax switch on the tower and tapered spacing.  Now 
you have the ultimate for overall perforamnce/band/dB/$$ and least headaches. 
 To beat that you will need 6 -100' towers with high gain monobanders, 6 
acres or more that can't be used for anything else, will have no spare time 
maintaining it or paying to have it serviced and a lot of shade from all 
those guy wires.  That installation a today's prices will cost you around 
$100,000 +/-, another $100,000 +/- for the land, your emotional health 
wondering about the affect of guy wires and should you have paid more for 
Phillistand (its a discussion of TT now)--just for a few and evasive ego 
bending DX dB's off into space never to be heard again--the most expensive 
dB's in radio.  If you are a contester--go for it.  It may cost you a divorce 
also.  For those who are just starting out, the 6 band 2 element properly 
designed quad, 50' tower, medium rotator, one coax, costs around $1500 and 
the least maintenance $$$ and time. That's about 38 dB less $$$ 24 hours a 
day that would have grown into a big retirement fund.  I ignored similar 
advice.  Money grows as will the maintenance head aches--dB's don't.  They 
tend to fade away in more ways than one.
     I now have the 6 acres and will have 6 or so inexpensive 100' towers on 
the highest ground conductivity in the US.  I'm retired and have the time and 
skills after 60 years to build and service anything quickly with a lathe, 
mill, workshop and test equipment.  I will also have 40-50' towers, 2 element 
quads and Rai-Beams also.  Count your blessings.  Don't do as I do--do as I 
suggest if you are still working and on a normal lot.  However, if you can 
afford to create a few lower angle dB's and still retire with enough to buy 
the electricity to run the station--do it and I'll help you do it at the 
least cost (I'm even looking into solar power--Y2K and all that). There are 
also tricks I've used to make horizontal antennas close to the ground on 
160-40M complete with the higher ones. It's rare fun beating the high 
antennas.  There are ways to compensate for the various technical and 
financial limitations.  K7GCO   
 
        

--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm