[Milsurplus] LM-7 Questions (B B A)

[Unserviceable but Repairable]

--->  Bring 'em Back Alive (F Buck)

Michael, John - yo

Don't have a LM-7 book, but I do for the BC-221.  No electrolytics

But the LM-7 may have a 110 vac p-s.  If so may I suggest following for
electrolytic reforms.

As u sed, all following is w. tubes cold.

First see if any trace of leaks @ electrolytics & change out those
where evidence suggests (Michael, on 'sticky' bathtub rubber to
entombed oil papers - prolly OK).  Next LIFT any bleeder R off ground & 
supply instrument w. excess B+ thru a high value series resistor for 
current limiting.  IE 500vdc & 20K for most stuff.

B+ will rise as electrolytics see fit & you're not condemned to 15
minute re-sets, temperature sensing, etc.  I just walk away for a
while.

Once B+ 'leveled out,' check for bad bypasses & couplers.  Catch these
right away.

Procedure lets you fix what's broken rather than do gawdawful procedure,
the unilateral recap.

Example night b4.  Have beaut of a Moto 52B7 3-way portable.  Complaint
was loud hum on plug in-age.  Professional recap estimates ran 6x price
on ebay.  Opened it's skull & found it looked new, did re-form per above
& 30 min.s later - voila, Sean Hannity!

Moral:  It's better to work smart than work hard

Hope this's a big help to y'all