[TowerTalk] Can take-off angle be too low?

[K7GCO@aol.com]

In a message dated 6/29/00 6:16:46 AM Pacific Daylight Time, 
tonno.vahk@hansa.ee writes:

<< Subj:     [TowerTalk] Can take-off angle be too low?
 Date:  6/29/00 6:16:46 AM Pacific Daylight Time
 From:  tonno.vahk@hansa.ee (Tonno Vahk)
 Sender:    owner-towertalk@contesting.com
 To:    towertalk@contesting.com
 
 
 Hi, I would like to hear your opinions about that topic. I have found many
 contradictory thoughts on it and very few clear and reasoned statements
 really.
 
 How important is it to have the ability of running very low elevation angles
 in upper HF contesting? How much does it add to the score if one can run 10
 meters with beams higher than 200 feet and get the take-off angle down to
 2-3 degrees? Here assuming one has also lower beams available. N6BV
 statistics actually indicate the high theoretical QSO percentage at 1-3
 degrees. To my mind it contradicts the somewhat common opinion that low
 angles get very little use. Would an efficient solution be to have one stack
 at 230 feet (e.g. 5/5) and one at low height if there was so high tower
 available to be able to open the band early, be strong meanwhile and close
 it late? All this having flat ground in mind for simplicity.
  
 73s Tonno ES5TV   t.vahk@hansa.ee
  >>
   This is an interesting concept.  The ultra high beam over 100' will hear 
and work stations no other antenna can in certain time slots.  However 
running a beam vertically polarized really lowers the angle when close to the 
salt water (liquid copper)(somewhat less over ground). Salt water 
installations are unfair.  W7DND here years ago pioneered that concept with 
simple antennas on a salt water beach inlet pointing east.  Over ground there 
is some raising of the angle off the ground due to a 180 degree reversal of 
phase at reflection for about 6 degrees just like for horizontal 
polarization.  There is a vertical polarization reflection loss of about 3-5d 
dB that also fills in the pattern nulls also.  This can be seen in Eznec but 
Eznec with all due respect has never radiated visually beyond the width off 
the screen.  Some authorities on TT sound like they never have either.

Unfortunately a vertical yagi like the CBer's used doesn't work worth a damn 
due to the tower being lit up like a LW inaddition to the detuning.  There 
are ways to isolate the tower I've tried and I finally came up with a way to 
do it.  There is another way like the CBer's did it of 2 vertical beams away 
from the tower on a horizontal boom for 3 dB more gain.  It sharpens the 
horizontal patterns which for contest runs is not desirable.  It has the 
heavy weight and wind resistance away from the tower and a good rotator is 
needed--like a Prop-Pitch.  Forget any other rotator as I keep suggesting.  
20M would be a practical limit.  2-40M Hex beams could be an exception.  I'm 
going to try them vertically polarized on my roof at opposite ends on a 
rotatable horizontal mast.  I will be able to get low angle in 2 directions 
and high angle.  Would you beleive I'll have a large Porp-Pitch to rotate the 
house on a railraod turn table.

I've used this on 10M (and 6M with 5 element beams-a great antenna) with the 
old Workshop 3 element beams of 5.5 dB gain thereby giving 8.5 dB gain.  I 
owned 28,503 MHz.  I was never QRM'ed to the point of being asked to move.  
This was on bad Seattle ground contrary to what the know it all experts have 
tried to preach to me on TT here.  I have 50 years of experience of vertical 
polarization on the air.  Some are experts in everything from child birth to 
reincarnation without ever experiencing either.  Actually using this antenna 
fits in there between child birth and reincarnation someplace.  On one ZS 
contact on AM I recorded him and played it back.  He recorded my recording of 
his recording and played it back to me.  I recorded this recording and played 
it back to him.  When I first tuned it up a station came back and gave me a 
40 over. We exchanged small talk and he asked what part of town I lived in.  
I thought that was strange as I hadn't given my call or he had given his yet. 
 I said South Seattle.  He was very surprised.  He was a LU2 that sounded 
like an American--and was.  He thought I was a local across town due to the 
signal strength and I had no QSB.  I knew this was going to be a great 
antenna and it was.  I increased it's effectiveness by adding another 3 
element 20' above on a telescoping mast and used various phasing 
combinations.  This is a great DX antenna contrary to those who live on and 
are over dosed with too much theory.and self proclaimed antenna wisdom.  The 
lower angle of only 8.5 dB free space gain and ground losses still had a 
beneficial affect.  I was accused of running big power and had surprise 
knocks on the door from hams investigating.  They walked away shaking their 
heads.  I'll have quad versions of this in SD over high conducting ground.  
Would you believe if you hear a signal that gives you RF burns off your RF 
gain control and audio burns off your audio gain control that will be my 
signal from one of these quad versions.

So I had the affect of a much higher antenna on 10M--at 35'.  45 degree 
polarization has less ground loss and still a lower angle of radiation than 
horizontal.  How do you like them RF apples?  

I have a yagi that I can get 6 instantly selectable polarization's (since 
1950) without interference from the tower.  I have a way to feed a quad to do 
the same thing.  I called it a "Secret Weapon" and that was challenged 
without him even knowing what it was nor did he ask--or did anyone else.  We 
need more investigative Hams if you expect to advance the state of the RF 
signal art.  They have a way to turn their investigative negligence into a 
criticism?  He sounded like a Political Liberal.

There is a story I read that about neglegence in research by a history book 
author.  A 5th grader read that in a naval battle in the Pacific the Japanese 
Navy suddenly withdrew.  Had they not done this the authors of the book said 
they would have wiped out the US forces.  The 5th grader wrote Admiral 
Yackasheri (whatever his name was) and asked him why he ran.  He was one of 
the few still alive.  He wrote back and said "Our intelligence warned us that 
we would have lost and you are the first ever to ask."  I've contacted many 
authors of antenna articles and have been told I was the only one that ever 
contacted them either by phone, letter or in person about their antenna 
article.  I know how many have contacted me from my articles and talks.  

To be first in a band opening you need a low angle and high towers can cost a 
lot.  If you are just a DXer than is willing to wait for when your antenna is 
optimum, try a 2 element beam 40'-50 high for the least possible cost and 
maintenance headaches.  For a small amount more of $$$, install 2 of them on 
a vertically polarized on a horizontal boom and one 15-20' above.  A good 
installation would be 2 Raibeam or Hex Beam tribanders for the least weight 
and wind resistance.  2-17-12M beams could have an optimum spacing for both.  
35-50' is all you need for height.  A tipping boom is ideal for 
installation--right from the tower.  Stacked vertically works great also if 
you can select either antenna or both instantly.  "I've been there and done 
that".  I'll have these combo's with my improved 5&6 band 2 element quads 
also.  Keep it simple and lost cost.  That concludes your antenna lesson for 
the day.  Ahem!   K7GCO

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