[R-390] Varying gain [WAS: Filters] (self healing caps)

[Tisha Hayes]

Self healing caps will rely upon supplying some amount of current across
the cap to "pop" a shorted area open. (like a pimple). I suspect the
thinking is that you definitely do not want any sort of current flowing
through the filter bobbins. They are wound with such fine wire they are
extraordinarily sensitive to cooking a winding open.

Then again we do not need to be putting a Sprague 715P, 600 volt cap in
there when a '225 would work (different grade of Sprague Orange Drop
capacitor). Just about anything we put in there is going to be better than
some BBOD (black beauty of death).

We attach too much significance to "premium" capacitors in every
application in the receiver. Putting 600 volt '715P's in some B+ bypass
application where it will never see more than 220-250 VDC is overkill.
There may be 4-5 spots in the receiver where a higher end cap would make a
difference (that "IF filter Killer Cap" and a few spots in the audio
chain). It has gone from practical to mystical and the "mor is betta"
approach seems to take hold.

The "pearls" documentation is a distillation of the best of what has been
posted in this email group for many years. It is better than reading
through thousands of pages of debate and takes it down to "only a few
hundred" pages. <lol>. It is sorted by topic to make your life a little
easier. Still, if you are looking for a quick reference to just one answer
you will be disappointed. Nobody on here thinks like that and We Li did not
take to revising the writings that far. They are cleaned up but still, in
reading you will see how we jump around in topics.

Another resource is the HSN (Hollow State News) collection. Just be aware
that many of the things on HSN are raw ideas and more than a few are just
wrong. It is a good historical reference to how we got to where we are now
with solutions that are generally accepted by the majority and proven out
by people trying things out.

If you printed out all of the significant documents like Y2K, the
modifications references, "pearls" and detailed  rebuild info (like how to
take an IF filter apart, clean it and rewind the bobbins) you will be
running around 2000 pages. A few years ago I printed it all up and it fills
two 3" binders.
-- 
Ms. Tisha Hayes/ AA4HA


*"neque est alter hujus universi locus quam anima"*
*('For there is for this universe no other place than the soul or mind')*
*-Arthur Schopenhauer*