[TowerTalk] Tower heighth question

[K7GCO@aol.com]

In a message dated 06.02.00 14:45:43 Pacific Standard Time, k9mi@hotmail.com 
writes:<< 
 I would like to thank everyone who took time to
 reply to my question about if it would be worth
 going from a 40 foot tower, to a 70 foot tower
 for my TH3.
 
 Most folks seemed to think it would be well worth
 the effort. Some did mention the fact that a 40ft
 antenna will beat out the higher antenna at times.
 
 Being on a small lot, and also "too dang close to
 my neighbors", I can't put up anymore then 1 tower,
 so it won't be able to do everything as well with
 just one hf beam at one heighth. So, nothing I can
 really do about that problem. Being "too close" to
 the neighbors means possible RFI issues running an
 Amp at 40 ft. So, I think I'll pass on that option,
 at least until I can get the antennas up higher.
 
 Luckily, our local tower climber has a good supply
 of used (but still in fine shape) Rohn 25g for $25
 a section. I'm sure he wouldn't sell me any defective
 tower sections, since he will be the one putting it
 up !
 
 So for now, my game plan is to go ahead with the tower
 project with the TH3, and then hopefully by next year,
 I can replace it with a C4. Then it will be time to
 save up for the amp. Thanks again for all the input.
 73/DX   Mike, K9mi   k9mi@hotmail.com  

 Mike: 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   
  
      >>

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