I'm in the process of replacing the vacuum relay in my Hercules II and
hope to improve the noise isolation. Here is a description of how it is
mounted and any suggestions for improvement are appreciated. Removing the
bottom cover of the amp we find another layer of aluminum to remove which,
on it's top side, houses the vacuum relay assembly. This relay assembly
consists of a small vacuum relay about the size of your little finger
mounted on a small circuit board. The board is about 1" x 2" and has
mounting holes in each corner. In each mounting hole is a standard, black
rubber gromet with a bolt/washer through it to hold it to the aluminum
base. Undert he board is some gray foam rubber. The foam seemed to have
been glued to the aluminum and was in very poor condition. In fact, the
foam was just a sticky, crumbled wad. I need to use some Goof-Off to
remove it.
I've never seen foam rubber deterioate so badly and I suspect it's
exposure to RF voltage may have encouraged this. After all, the foam was
stuck directly to the 500 watt output solder joints of the relay and it
was quite gooey and sticky. Wouldn't this conduct to a degree? Now I
suppose the foam was a noise or resonance damper but something better
needs to be used to prevent the relay clanging. Something that won't
absorb moisture and is not affected by RF is needed. I could even wrap
this material around the relay assembly if I knew what to use.
Any suggestions?
Steve Ellington N4LQ
N4LQ@IGLOU.COM
--
FAQ on WWW: http://www.contesting.com/tentecfaq.htm
Submissions: tentec@contesting.com
Administrative requests: tentec-REQUEST@contesting.com
Problems: owner-tentec@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|