[TowerTalk] Antenna Grease--Deficiencies and Remedies

[K7GCO@aol.com]

In a message dated 6/26/00 10:09:51 AM Pacific Daylight Time, 
wbh3@daimlerchrysler.com writes:
<< 
 FWIW when I built my  kt34-xa about 7 years ago, KLM supplied a little can
 of copper-colored paste to put on the joints.  After a move and when I
 was reassembling the end units I found this paste had turned very solid and
 seemed to be a good insulator as the resistance checks I made on each
 element end were very high.  Don't know what KLM used but I don't think it
 was very good stuff.
 
 Bill Haselmire  WX8S
  >>
     Right on Bill!  It's nice to see evidence coming out that certain Goops 
don't do what they are supposed to do.  So far I've had support on TT for 
just about everything I've suggested.  Many think that just being able to get 
the elements apart years later is the main requirement.  I'll say again 
"MAINTAINING ZERO CONTACT RESISTANCE FOREVER IS THE MAIN REQUIREMENT".  I 
hope this concept has been fully and finally established after many efforts 
and warnings to all the poo poo'ers.

In the Spring ones thoughts turns to love and quads.  Quads only have one 
soldered joint per element that remains ZERO resistance year after year if 
properly soldered.  Properly made like Antenna Marts they stay up year after 
year.  Antenna Mart has some "Yagi Tranquilizers" they give out to yagi 
owners who can't figure out why their yagi's don't do as well as they once 
did.  Yagi's tend to suffer from the "Dreaded Goopitus."  It's a form of 
"Aluminum Contact Capacitive Cancer."  When the Goops fails the beam fails to 
perform with all those capacitive and resistive joints.  

Anti-Seize with ALUMINUM PARTICLES appears to have an immunity to the 
"Dreaded Goopitus" and "Aluminum Contact Capacitive Cancer."  I plan to run 
accelerated tests on it myself.  Mike Ercolino of Telrex 40 years ago told me 
of accelerated tests he ran on a Goop he used with salt water and heat.  He 
didn't like Penatrox either.

Raibeam supplies Anti-Seize with it's beams even though it cost more.

Take your yagi down and measure the joint "Impedance's."  Note I said 
"Impedance's."  That means there is a "reactive component" leaning in the 
capacitive direction.  If an ohmmeter acts like it's connected to a 
capacitor, the best Chemotheropy is to clean the joints thoroughly and recoat 
with Anti-Seize with aluminum particles.  I'll keep you posted on my 
longevity tests.  

Another yagi anti contact cancer remedy I have used is to run full length on 
the yagi elements an aluminum foil tape with contact adhesive.  This was 
available commercially.  I have used long strips of copper foil I coated with 
contact adhesive This was available commercially as a tape but a bit pricey.  
As I recall it even had particles of copper in the adhesive but is of little 
value to RF--only at the edges.  I spun the element in the lathe and wrapped 
plastic tape over it to keep it clean and highly conductive.  Strips of 
shrink on tubing is faster but more expensive.  I'm going to do this on a 10M 
director and GD it just with either foil and then the tape to see what the 
resonant frequency changes are.  It also made it easy to solder the feedline 
to the DE.  I still have the elements and use them as they are Zero 
Maintenance Elements.  On one 20M 3 element beam tuned for max F/B, I noticed 
the feedpoint resistance went down from 40 to 35 ohms when the copper foil 
was added to the director.  I'm going to put this combo in Eznec and see what 
happens and also increase the tubing diameter .005".  The copper foil raised 
the Q of the director and apparently bit into the DE more and possibly 
increased the gain.  

The Hex Beam doesn't need any Goop or solder on it's elements.

The highest standard of competitive performance in the antenna kingdoms is a 
2 element quad, RaiBeam or a HexBeam at say 40-50' high. They work great 
higher also as the wider vertical pattern fills in the additional higher 
angle reflection factors with more RV than do the higher gain beams.  It's 
rare fun beating the long boom big ego guns with a 2 element beam.  For the 
least cost and maintenance there is no better buy ideal for all the retirees 
in ham radio now and the few new hams coming into it.  If you want more line 
of sight gain and a lower angle, the cost skyrockets as does the "Dreaded 
Contact Capacitive Cancer."  

Bill Haselmire--you made my day.
K7GCO

--
FAQ on WWW:               http://www.contesting.com/FAQ/towertalk
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com