I thought I might continue to save my old caps because some restorer
might want the 'original waxed paper' to stuff a new cap into.
Do I need to take more meds?

In article , "Frank
Dresser" writes:

Just as speculation, let's say cap manufacturers have learned to make
electrolytic capacitors with good precision at little extra cost. And let's
imagine that setting the target capacitance to 5% - 10% low reduces the cost
of the "active ingredients" by 5% -10%. Well, that would be a nice reward
for knowing how to do the job!

This makes very good sense.
I suspect that back in the old days, manufacturers would throw in up to 100%
extra foil plates area just to make sure they at least met the rated
capacitance. So you would get caps well over the ratings.

But yes, once they got the process down really tight, why toss in extra
material. In fact, shaving it on the low side is just what the front-office
bean coutners probably tell them to do nowadays! --Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.

In article , "Frank
Dresser" writes:

Just as speculation, let's say cap manufacturers have learned to make
electrolytic capacitors with good precision at little extra cost. And let's
imagine that setting the target capacitance to 5% - 10% low reduces the cost
of the "active ingredients" by 5% -10%. Well, that would be a nice reward
for knowing how to do the job!

This makes very good sense.
I suspect that back in the old days, manufacturers would throw in up to 100%
extra foil plates area just to make sure they at least met the rated
capacitance. So you would get caps well over the ratings.

But yes, once they got the process down really tight, why toss in extra
material. In fact, shaving it on the low side is just what the front-office
bean coutners probably tell them to do nowadays! --Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.

"Mike Knudsen" wrote in message
...

This makes very good sense.
I suspect that back in the old days, manufacturers would
throw in up to 100%
extra foil plates area just to make sure they at least met
the rated
capacitance. So you would get caps well over the ratings.

But yes, once they got the process down really tight, why
toss in extra
material. In fact, shaving it on the low side is just
what the front-office
bean coutners probably tell them to do nowadays! --Mike
K.

Oscar loves trash, but hates Spam! Delete him to reply to
me.

I don't think I've ever seen an electrolytic capacitor read
more than 20% high, and even that range is very rare. Even
on the few low ESR survivors from the late 40's - early
50's. I'm not using a lab quality bridge, or checking large
numbers of electrolytic capacitors, so I can't come to
really firm conclusions. But I'm thinking the manufacturing
process was reasonably precise by 1950.

I don't know if the comparision holds, but carbon
composition resistors were getting more precise all through
that era, as well. The 5%ers were pretty common around
1970. I have to wonder how much expense was added to the
more precise resistors just for keeping extra inventory.
There's about twice as many values for 10%ers as 20%ers.
Double it again for the 5%ers. Assuming the cap makers
could reliably come with 5% electrolytics, would there be
any value to stocking 4 times as many values? I can't think
of any. They are used almost entirely for power supply
filtering, or audio coupling. So maybe they kept the old
20% spec on 5% tolerence caps only to keep inventory simple.

Frank Dresser

"Mike Knudsen" wrote in message
...

This makes very good sense.
I suspect that back in the old days, manufacturers would
throw in up to 100%
extra foil plates area just to make sure they at least met
the rated
capacitance. So you would get caps well over the ratings.

But yes, once they got the process down really tight, why
toss in extra
material. In fact, shaving it on the low side is just
what the front-office
bean coutners probably tell them to do nowadays! --Mike
K.

Oscar loves trash, but hates Spam! Delete him to reply to
me.

I don't think I've ever seen an electrolytic capacitor read
more than 20% high, and even that range is very rare. Even
on the few low ESR survivors from the late 40's - early
50's. I'm not using a lab quality bridge, or checking large
numbers of electrolytic capacitors, so I can't come to
really firm conclusions. But I'm thinking the manufacturing
process was reasonably precise by 1950.

I don't know if the comparision holds, but carbon
composition resistors were getting more precise all through
that era, as well. The 5%ers were pretty common around
1970. I have to wonder how much expense was added to the
more precise resistors just for keeping extra inventory.
There's about twice as many values for 10%ers as 20%ers.
Double it again for the 5%ers. Assuming the cap makers
could reliably come with 5% electrolytics, would there be
any value to stocking 4 times as many values? I can't think
of any. They are used almost entirely for power supply
filtering, or audio coupling. So maybe they kept the old
20% spec on 5% tolerence caps only to keep inventory simple.

Frank Dresser

In article , "Williams"
writes:

I thought I might continue to save my old caps because some restorer
might want the 'original waxed paper' to stuff a new cap into.
Do I need to take more meds?

Nope, you make sense. Maybe not so much demand in the Ham BA world, but over
on radio+phono you'll find purists who want caps to stuff. The problem is,
they already have the original old caps in the radio they're restoring, so they
don't need yours.

But -- some enterprising retiree may want to stockpile pre-stuffed restored
caps and sell them to other restorers, ready for insertion in the radio. If
so, he'd want yours for starters to build up inventory. Ultimately, he'd take
the old ones in exchange, but meanwhile he needs extras.

Hopefully he'd pay enough to cover the postage :-) --Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.

In article , "Williams"
writes:

I thought I might continue to save my old caps because some restorer
might want the 'original waxed paper' to stuff a new cap into.
Do I need to take more meds?

Nope, you make sense. Maybe not so much demand in the Ham BA world, but over
on radio+phono you'll find purists who want caps to stuff. The problem is,
they already have the original old caps in the radio they're restoring, so they
don't need yours.

But -- some enterprising retiree may want to stockpile pre-stuffed restored
caps and sell them to other restorers, ready for insertion in the radio. If
so, he'd want yours for starters to build up inventory. Ultimately, he'd take
the old ones in exchange, but meanwhile he needs extras.

Hopefully he'd pay enough to cover the postage :-) --Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.

Williams wrote:
I thought I might continue to save my old caps because some restorer
might want the 'original waxed paper' to stuff a new cap into.
Do I need to take more meds?



Send 'em this a way, Jimmy. Ken G just blessed me with some but I can
always use more!
-Bill M
exray at caribe.net

Williams wrote:
I thought I might continue to save my old caps because some restorer
might want the 'original waxed paper' to stuff a new cap into.
Do I need to take more meds?



Send 'em this a way, Jimmy. Ken G just blessed me with some but I can
always use more!
-Bill M
exray at caribe.net

Mike Knudsen wrote:

Nope, you make sense. Maybe not so much demand in the Ham BA world, but over
on radio+phono you'll find purists who want caps to stuff. The problem is,
they already have the original old caps in the radio they're restoring, so they
don't need yours.

Not always...thats why I need more. Often times the original caps have
already been hacked out or are in too terrible a condition for restuffing.
I try to keep some made up ahead of time and where a set like a Zenith
or Philco uses brand specific ones I like to replace with the same. I
considered stuff-n-sell but it really is a time consuming task. I'd
feel stupid trying to sell them at what they are worth dollar-wise in
time...and of course anyone can do their own for free if they really care!

But -- some enterprising retiree may want to stockpile pre-stuffed restored
caps and sell them to other restorers, ready for insertion in the radio. If
so, he'd want yours for starters to build up inventory. Ultimately, he'd take
the old ones in exchange, but meanwhile he needs extras.

Hopefully he'd pay enough to cover the postage :-) --Mike K.

I beg for these things! And of course always pay postage!

-Bill