[TowerTalk] Hy-Gain trap rebuilding question

[Dale Martin]

On Monday, August 25, 1997 6:55 AM, Fred Hopengarten[SMTP:k1vr@juno.com] wrote:
>From:
>Fred Hopengarten  K1VR               617/259-0088
>Six Willarch Road
>Lincoln, MA 01773-5105
>permanent e-mail address:  fhopengarten@mba1972.hbs.edu
>
>On Sat, 23 Aug 1997 13:10:13 -0600 (MDT) John Brosnahan <broz@csn.net>
>writes:
>> I recently acquired a TH-6 and a TH-2
>>and plan to make a TH-7 out of the pile.  Any thoughts or caveats 
>>I should be aware of?  Having trouble pulling the aluminum cover 
>>from the trap to check the internal connections.
>>
>>Thanks----John  W0UN
>
>
>K1VR replies:
>
>1.  The aluminum cover on the trap is held on with a "dimple."  You can
>try to force the cover off, in the hope that the dimple (or dimples)
>aren't too deep, and, with enough persuasion, you will be able to get it
>off.  K1MEM once helped me do this by creating a "tool" (as in tool and
>die) -- or was it a die? -- which he slipped over the tubing and then we
>pounded the tool with a hammer.  Pounding on the aluminum cover with a
>hammer is a bad idea.  Instead, pound on the coil form with the force
>fully distributed around the circumference underneath the aluminum cover.
>
>2.  Replace the trap caps.  All of them.  Get replacements from Judy (I
>think that's her name), or perhaps it is Linda, at Hy-Gain.  She takes
>credit cards and ships UPS.  It is easy.  N4KG then recommends covering
>them with Scotch 33 or 88 to further protect them next time around.
>Drill a weep hole on the down hill side of the downhill end of the trap. 
>Forget that anyone on this reflector ever wrote about whistling caused by
>that small weep hole.
>
>3.  While the traps are apart, examine them VERY closely for carbon
>tracks and aluminum oxide.  Clean the trap before re-erecting.  But you
>knew that.
>
>Good luck!  -- Fred K1VR
>
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>

Also, perform a resistance check from aluminum tubing piece 
to aluminum tubing piece.  I took apart my Cushcraft A3 traps 
and when I found one that would not resonate with the GDO, I 
found it open with an ohmmeter.  It looked perfectly clean and 
otherwise undamaged.  I unscrewed the sheetmetal screw 
securing one coil end to the aluminum tubing piece and found 
it to be the one with the problem.  I cleaned up the joint (the 
wire, screw, and area around the screw hole), put down some 
noalox, and secured the coil end back to the aluminum tubing 
piece.  It has been working FB ever since (Oct/Nov96).  

Good luck.

73,


Dale Martin, KG5U
kg5u@hal-pc.org
http://www.hal-pc.org/~kg5u


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