[TowerTalk] Traps--Yagi Joint Losses

[K7GCO@aol.com]

In a message dated 7/18/00 5:47:05 AM Pacific Daylight Time, w9ol@dataflo.net 
writes:

<< 
 > The Driven Element.  Test equipment needed is "one hand."  I've made
 > believers out of Doubting Thomas's about the need for regular "Yagi Joint
 > Maintenance."   K7GCO
 
 
 Sir
 After reading your email I'm curious.
 I just put up a multiband trapless type yagi.
 I prepped all joints with Noalox and used ss hose clamps.
 Double checked all clamps for tightness.
 
 I've seen many types of joint connection, rivets, self tapping screws and
 clamps.
 Outside of heliarc welding, what do you think is the most secure joint
 connection technique?
  >>
I like all SS hose clamps that I grease up the threads with Silicone grease 
so I can really tighten it.  For convenience I've silver soldered with 
Eutectic10-20 solder a 1 1/4" SS washer in the screwdriver slot.  I grease 
the tubing under the clamp also or Aluminum Oxide will occur.

I also use a flea market aluminum solder on the telescoping joints after 
cleaning them real well and after 6 years now the joints are perfect with 
ZERO Resistance, NO Maintenance and NO Heating.  I may have the only yagis in 
existence that can make that claim.

The self taping screws require another short length of smaller tubing inside 
to give a full 1/4" of grip surface.  The hole in the outside tubing should 
be larger so some compression can occur.  Then it's only a localized 
pressure.  The screw and hole should be well coated with Silicone grease.   
It cannot compare to a real tight SS clamp making contact for 360 degrees.   
K7GCO

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