[ARC5] BC-AN-229 Follies, part 2

[Ben Hall]

Hi Tim and list,

On 11/13/2014 11:43 AM, Tim Des wrote:
> Thank you for taking the lead on the receiver and for posting your
> progress. How one battles with the condensers is valuable information and
> fun to her about.

I really enjoy reading posts on how others fix things as I always learn 
something.  From my posts...all people may learn is what not to do!  ;)

> I am looking forward to part 2. Who knows, maybe someday there will be the
> *Son of the BC-AN-229  *or the *BC-AN-229 that Ate Cleveland :) *Thanks
> again.

Ta da!  Part 2 to follow.  We'll have to see about "Son of the 
BC-AN-229" or the "BC-AN-229 that Ate Cleveland."  :)  Pittsburgh may be 
a little bit tastier.  ;)

So...last installment I talked about "dremeling" the side-mount capacitors.

I probably should describe this a little better.  I suspect the can of 
the "side" caps were made from two pieces of plated brass.  There is 
what I'll call the "can", which has the terminals and the mounting lugs. 
  Then there is a plate pressed into the bottom of the can and soldered.

When I cut into the "side mount" units, I cut the plate on the bottom 
close to the solder joint.  The idea was to get access to the guts 
without impacting the mounting or strength of the cap.

"Top mount" units are different.  There is the can with the mounting 
lugs, and the terminals are on the plate soldered into the bottom.  So I 
can't cut out the bottom plate, was there is no good way to reattach it.

So what I did was this - with a very fine tooth saw (a Zona hobby saw - 
around $10 at the hobby shop or e-place) I cut the can around its 
circumference about 1/4" above the mounting end of the can.  This 
retains good mechanical strength between the terminals and the mounting 
lugs...but makes re-attachment of the can problematic.

After the cut is made...pulling out the old guts (yeech!) is relatively 
easy.  The leads from the terminals into the guts unsoldered easily.

With the guts gone, I can now stuff two 0.47uF units in there pretty 
easily.  Keeping the lead lengths short required drilling an additional 
ground hole.

To put the can back on, I mixed up some epoxy, dabbed it on the sawed 
joint, put the two halves together and held it in place with some 
plastic tape.  It is fiddly and requires almost three hands.  The tape 
helps force the epoxy into the joint...as well as holding it for the 
epoxy to dry.

After a couple of days, the tape came off...and...ugh...not the 
prettiest thing ever.  I filed the epoxy smooth...and still...ugly.  So 
I wrapped the joint with a piece of 1" wide plain aluminum tape.  It 
looks unusual...but better.  :)

Now to put it back into the set and hook it back up.  :)

Thanks much and 73,
ben, kd5byb