[Collins] Identifying BBs

[tbeltran]

Thanks for all the very helpful replies.  I thought I would share some info
people sent, particularly since one person has a similar problem.

Ralph, W8BVH has a similar problem, with his A-4, where the R87 is also
burnt.  I certainly take Jerry's suggestion, and look at changing all the
black beauties and the aluminum electrolytics.  I counted ten BBs.  What do
people use as a replacement for the micas?  One person emailed me and said
he uses dipped micas.  I've also heard some discussion about lower noise
capacitors for use in the audio stages, as well as using metal film
resistors in the audio stages.  I've read the archives and other info on
recapping, but the articles don't say specifically what the replacement
should be (with the exception of the orange drops), at least for someone
like me with good soldering and mechanical skills, but not much formal
electrical skills.  I rebuilt my Drake R4C a few years ago, it came out
quite nice - Rob Sherwood said the work looked very good.  So I feel
confident to do the actual mechanics of soldering ect., I just don't have
quite the background to decide upon proper replacements.  I'm not too
concerned with cost - this is the only A-4 I have, and I plan on using it
with my kws-1, so I want to do a good job.

Bjarni  TF3BM, stated this:

"I would check the transformer T4 Normally there is no current going
through R85 since T4 primary is across R85. Check the transformer. Also
since R87 has over heated and not R86
there could be a short between primary and secondary in T4."

I took the can off of the T-4 transformer, and it looks fine, I'm not sure
what I would look for, except perhaps a short between the primary and
secondary windings?  The radio looks like new - I took some very close up
digital pictures (about 30) for a record before I start into the radio, if
anyone has any interest, or needs to see what the original looks like for
their own project, let me know.  I don't think this radio has been worked
on - there are certainly no modern parts.  Tom W6EIJ