[TowerTalk] Lexan and element linkage

[K7GCO@aol.com]

   This was supposed to have been sent to aa4nn@juno.com in regard to an 
insulator problem he had instead of TT.
<< 
   As I said in previous E-mail, the more the end loading, the shorter the 
resonating stub and the higher the Q and voltage on the resonating stub on 
the end.  I had the Latten Lab 200 uh loading coils at the ends of a 40M 
dipole and only 3' of wire to resonate it on 75M.  I worked with narrow 
bandwidth on 75.  He dropped the 3' wire vertically down with no 
insulator--it was hot.  Latten's design ran a rope from the end of the coil 
insulator to the support. He advertised this antenna in QST 30-40 years ago.
      You have longer wires at the end of the loading coils on 160 in terms 
of wavelengths but you have far more power.  The manufacturer apparently 
didn't know of the potential voltage on the insulator or he didn't go quite 
far enough in reducing the amount of loading.  But as I pointed out, the less 
inductance requires larger wire on the band it is used as a choke. Hold the 
key down for 1 minute and drop the coil to the ground quickly and see if it's 
hot.
      I came up with a way to cool the voltage at the end of the 3' wire that 
cracked insulators at 300 W.  Extend 2 wires from the end of the wire and 
insulator hole beyond the other end of the insulator at about 60 degrees 
about 2" and make a loop at the end connected to these 2 wires.  It takes the 
high voltage end beyond the end of the insulator and distributes it around 
the loop instead of a small loop in the insulator.
 K7GCO >>

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