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[TowerTalk] Re: Scaling of Quads To Other Frequencies

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Subject: [TowerTalk] Re: Scaling of Quads To Other Frequencies
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Date: Tue, 23 Nov 1999 16:49:12 EST
  There are those who claim that "quads don't scale pattern wise like 
  yagi's do and have to be retuned."  Careful comparison can prove this and I 
  intend to do it.  Yagi's are hard to scale physically as brass model 
  tubing diameter steps are too wide compared to the copper wire diameter 
  steps.  Has anyone observed that quads don't scale well as the frequency 
  difference increases in a controlled experiment?
       In the computer they scale,  I used a function in Eznec (FRr) to scale 
an antenna from 24.95 to 146 MHz or a .1709 reduction in spacing and length.  
I had to increase the FR to 155 MHz to get the same pattern.  Then I 
remembered it doesn't scale the conductor size.  So I used the same scale 
factor to reduce the #12 wire and it ended up .014" which sounded right.  
This time I had to use a FR of 165 MHz.  Wait a minute.  I had the units in 
WL and it was a very large diameter.  When I changed the wire diameter to 
.014"--Presto!  At 146 MHz I get exactly the same pattern as on 12M.  So it 
scales in Eznec.  I have proved that yagi's do scale in Eznec and in actual 
practice so I expect quads to scale.  The only thing that doesn't scale is 
conductivity which can affect the Q of a parasitic element which can affect 
the gain.
       I'm going to be obtaining all kinds of fiberglass rods and selling off 
  some of my aluminum tubing.  I plan to scale my quad designs at 100 MHz and 
  use horizontally polarized FM stations as RF sources which are on 24 hours 
a day 
  in flat country in SD.  I'll use an FM receiver with an S meter for my FS 
meter.  I also have a TV/FM FS meter that is ideal for what I want to do.  If 
  the 100 MHz pattern checks out with the Computer software pattern, I'll 
  scale it on 10 M and lower.
      One beauty of using the FM BC band as RF sources is that it's wide 
enough to 
  check it's F/B over 88 to 106 MHz.  I'll have permanent reference quads up 
at the 
  same height also to compare gain with.  The copper wire elements will be 
  and there will be no electrical deterioration of the reference.  I'll do 
some FM DXing 
  also.  Quads are very easy to model to any frequency for spacing, length 
and wire 
  diameter as there are many available diameters of copper wire for easy 
scaling and
  the ability to end up with say #12 on the desired band.  There is a Channel 
2 TV
  station in SD 90 miles from me that would also be an ideal RF source for 
the first 
      A quads design has been limited to square or diamond.  There are many 
  other configurations I have used that are highly beneficial.  No one else 
  apparently done this or someone would have published something.  The area 
  even further quad improvement has only been scratched.
     There are countless examples of advanced or improved products taking a 
  time to really catch on.  Mentalities just couldn't grasp the significance 
of the 
  advanced RF or any design.  Quad and yagi sales and performance have been 
  crippled by many poor mechanical and feedpoint designs of manufacturers who 
  used all kinds of compromises to cut costs and appeal to cheap skate hams.  
  There is a special place in hell for these manufacturers and the cheap 
skates who 
  buy this stuff who ruin the market for everyone else.  I even wasted my 
money on 
  one also when I knew it was bad instinctively, in Eznec and then on the air 
just to 
  prove it to myself I guess and be able to speak with authority on my 
     On 20M I'd call CQDX on Europe and a rare China station came back--off 
  side.  I'd call CQDX on JA and a LU comes back.  I was stronger when I 
  it on them.  Contact after contact was like this.  The Mfg. claimed "I got 
them the  
  long way around." Ho Ho Ho  It was hard to peak a signal even with a fast 
         I used to tell students that if they develop or improve a product, 
  limit the improvement.  If too advanced, the educational program will take 
  too long to catch on, will be too costly.  Years later after your patent 
  run out, someone else will steal and claim the idea after you bankrupted 
  trying to promote it.  A patent is only a license to sue at your expense 
  it is in force.  Make only small improvements they can understand and you 
  profit from the sales each time.  A quad is a huge improvement in many 
  easy for most anyone too see and hear but the wise ones have trouble seeing 
  it.  I sell some "Yagi Tranquilizers" to yagi users who are constantly 
  frustrated at being aced out by quad users.  I sell "RF Antenna Wax" to 
  users also.  It needs all the help it can get.  Would you believe "it 
  up the RF Electrons so fast they get there just before they start"?
       Early Quad designs of mfgs. and in ham articles were susceptible to 
Ice loading.  A DXer wrote an article on DX Antennas and left out quads.  I 
wrote him and asked why?  He said "in the NE we have too much ice loading."  
Here poor mechanical design resulted in his leaving the quad out of the 
comparisons and technically invalidated the whole article.  Totally Absurd!  
I told him to take a look at Antenna Marts Mechanical and Feedpoint Designs.  
K7GCO Ken Glanzer

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