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[TowerTalk] Viking KW matchbox.

To: <>
Subject: [TowerTalk] Viking KW matchbox.
From: (
Date: Tue, 23 Oct 2001 04:27:28 EDT
     In a message dated 10/19/01 3:51:42 PM Pacific Daylight Time,  
     writes: << 
         From my readings of things and listening to things, the idea of 
      near, at, or in the antenna appears to be the best thing to do for most 
      operation.  I have been looking at the screwdriver types of antennas, 
      even offer a dipole arrangement.  I think that the only drawback would 
      the lower radiation resistance.  But I have not been able to figure 
      out or the efficiency of tuning in the shack versus tuning at the 
      for the same size antenna.  Then of course for smaller antenna tuning 
       Chris opr VE7HCB
     Chris: A tuner at the antenna has some merit for complex loads but coax 
is now the major feedline to the shack.  A remote tuner has to be tuned and 
I've done it from the shack to the tuner with 2 selsyns.  You also need a 
band changing switch.  You are suggesting something that is very inconvenient 
and slow.  Using a tuner at the antenna admits you don't know how to create 
50 ohms with a matching system like a "T Match, L Network or a Series Xc" for 
use in Verticals or L's which the tuner is now required to do.  Transfer the 
task of impedance matching regardless how complex it is to the shack end of 
very low loss (that never changes) controlled open wire line length--in the 
shack.  I have used a remote tuner at the bottom of top loaded vertical on 
the LF's as it was voltage fed there and coax loss is low on LF.  
 In case there are any who have repeatedly missed the message, there are very 
simple techniques from the Stone Age of the last Century where you can match 
complex Z's to 50 ohms in very low loss, a repeatable and recordable form.  
Nobody has found a better way to do it--that has shown it.  I will personally 
reward anyone that does it--with a reward of my choice, naturally.  Hopefully 
this will inspire someone to give it a try.
     One of the main reasons for a tuner is to match the Z at the end of open 
wire line preferably of a certain length--to 50 ohms.  You let your fingers 
do the matching in the shack.  The antenna load can be resistive in the 
middle of the band or it can be complex on the band edges at the antenna or 
end of the feedline.  Maximum power can transferred to either load with the 
least loss over the entire band(s) by matching the Z at the end of the open 
wire line feedline in the shack which a MB will do.  The open wire line is 
the easiest to repair if damaged (coax is discarded), lasts for a lifetime, 
costs the least of any feedline in particular if you make it yourself.  After 
the settings are determined and recorded across the band they can be quickly 
selected without checking the SWR each time.  Remote tuning has a few 
   Heathkit had a box with a "Motor Driven Series Xc Variable" that was 
installed at the feedpoint in one leg of a dipole or inverted vee for broad 
banding purposes.  Even though it was just in one side it worked just great.  
It's "just another example" of where a "Series Xc" has been used to increase 
bandwidth over the band "Very Successfully."  It can be also used to obtain a 
higher Rr value for verticals or L antennas in addition to increasing the 
bandwidth--with a single reactance component remotely tuned.  Many seem 
brainwashed they have to use a 1/4 wave vertical length when in most cases 
the Rt is around 40 ohms.  So make it a bit longer and add a fixed series Xc 
such that it gives 50 ohms.  Or add a motor or selsyn driven Xc to obtain the 
lowest SWR over the entire band.  This should be standard practice for the 
progressive in this Century.  
 I keep getting E-Mails with this basic thread--"I've read your 
recomendations and finally decided to try the Series Xc in vericals or L's or 
the MB and open wire line on and on and on despite what the Poo Pooers say or 
those who never try it and--it works.  Why do they do that?"  I suggested 
"they ask them!"   Progress is tough unless the "Professional Poo Pooers" 
supposedly generate an idea which is of course very rare.  Progress is not 
their state of the mind. 
      Regardless how far you look you will never find a more useful technique 
than  a "Series Xc."  Those who "Slam It Repeatedly" do not give any other 
technique that is more useful or what they use.  I'm still waiting.  I'll 
give credit where it's due to anyone.  I'm looking for new ideas all the time 
regardless who they come from.  k7gco                    

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