[Elecraft] Off Topic Help with Heathkit

[Allen Ward]

Date: Thu, 19 Jun 2003 19:19:56 -0400
From: ke2qr@arrl.net
To: elecraft@mailman.qth.net
Organization: Fred Jacobowitz
Subject: [Elecraft] Off Topic - Help with Healtkit

Any suggestions on how to clean/restore rotary gang switches on a =
Healtkit
HW-100.  I have to fiddle with the Band switch to get it just right.  =
Are
there people out there that repair these beloved Heathkits?

73 de KE2QR
Fred Jacobowitz

I went through a misused SB-102 and repaired and re-aligned everything.  =
I found that the bandswitch  was finnicky and sometimes you could get =
full 100 watts out and the next time only 25 watts.  Very careful =
cleaning with an eraser and contact cleaner helped some.  Then I noticed =
that the switch had solder lugs on both sides and these were connected =
by a little bar of metal swedged between the lugs.  There appeared to be =
some corrosion at these "swedges."  Flowing solder with a very hot iron =
on both sides of the lugs and on the PCB's cured the bandswitch problem. =
  The Heathkit scheme is to short out progressive coils of a series =
connected group for the low-level rf section.  The switch wafers are =
soldered to PCB's so if there is a bad/intermitten connection it has the =
effect of mistuning one or more sections of the rf string.  You have to =
remove a shield or two and maybe even a wafer and PCB.  Be careful!!  =
The PCB's are phenolic and are brittle.  This equipment is ~30 years old =
and the original builder may not have done a very good job.  Good luck.
Allen KA5N   K2  #1107


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