View Single Post
  #3   Report Post  
Posted to sci.electronics.repair
Kirk Johnson[_2_] Kirk Johnson[_2_] is offline
external usenet poster
 
Posts: 4
Default Valve/tube screening can problem


"N_Cook" wrote in message
...
Mesa Nomad 55 with one of the 12AX7 snow capped and a neat ring around the
top of the glass envelope. Obviously due to the bed-spring gauge of spring
inside the can. 2Kg to halve the spring length, probably 2/3 compression
in
use.
No point in replacing without changing all the springs or something. How
to
reform a weak straight compression spring (easily available) to conical or
otherwise fit inside the can and the glass touching end be centrally
posistioned. ?
Secondly there is no dedent to stop the cans rotating other than use of
heavy springs - catch 22. What to do, retrofit, without taking the amp
apart
to get to the inside of the chassis. So far I've discovered a working ,
but
not elegant solution. One of those brass-eyelet hand pincer/dies pushing
the
die pin outwards to deform a pip in the aluminium, outwards, 1/4 way round
so it locates in one of the 2 chassis cutaways. Needs some rubber padding
on
the outside so the other anvil half does not excessively damage that local
area. Any other solutions anyone else has found, particularly forming or
re-forming spring metal to something like conical My attempts are very
wonky.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/



Maybe give this a try lad

http://www.imagefap.com/image.php?id=1988478267

Always works wonders for me!

Kirk Johnson
"EXTREME Stretching Specialist"