"Frank Dresser" wrote in message
...


Here's the results, checked on a Heathkit IT-28:

BC HP 68ufd 200V
68-62-60

BC HP 47ufd 200V
43-44-46-44-44-43-45-45

BC HP 33ufd 200V
33-30-29-31-31-30-33-32

Xicon 47ufd 160V(Marked +/- 20%)
44-43-43-46-43-44-48

Xicon 33ufd 160V(Marked +/- 20%)
32-34-34-34-34-32-33-32

Panasonic 47ufd 450V
45-46-43

Ducati 100ufd 25V (about 30 years old)
98-100-100-98-105-95-105-102-110-100-110

Planet Liticap 40ufd 450V (used pull, maybe 40 years old)
38

Frank Dresser

For a radio that I intend to use regularly, I follow the credo, "kill 'em
all, let God sort them out." Why would you take a chance that a decades-old
electrolytic will survive for another hour, day, or week? You can replace it
as fast as you can test it, and if you guess wrong, it may cost you an
expensive power transformer. For the price of a few lattes or a couple of
beers, you can afford to put new electrolytics in your boatanchor and sleep
soundly :-)

If you want everything to look original, you can stuff new capacitors inside
the old containers. See the article at http://antiqueradio.org/recap.htm .

Happy listening.

Phil Nelson
http://antiqueradio.org/index.html

For a radio that I intend to use regularly, I follow the credo, "kill 'em
all, let God sort them out." Why would you take a chance that a decades-old
electrolytic will survive for another hour, day, or week? You can replace it
as fast as you can test it, and if you guess wrong, it may cost you an
expensive power transformer. For the price of a few lattes or a couple of
beers, you can afford to put new electrolytics in your boatanchor and sleep
soundly :-)

If you want everything to look original, you can stuff new capacitors inside
the old containers. See the article at http://antiqueradio.org/recap.htm .

Happy listening.

Phil Nelson
http://antiqueradio.org/index.html

In article , "Frank
Dresser" writes:

Here's the results, checked on a Heathkit IT-28:

Interesting. With very few and small exceptions, every cap measured LESS than
marked. And we thought lytics were being made with very high positive
tolerances, up to 100% or double the value.

I guess you get (almost) what you pay for, no mas! --Mike K.

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

In article . net, "Phil
Nelson" writes:

For a radio that I intend to use regularly, I follow the credo, "kill 'em
all, let God sort them out." Why would you take a chance that a decades-old
electrolytic will survive for another hour, day, or week? You can replace it
as fast as you can test it, and if you guess wrong, it may cost you an
expensive power transformer.

Amen. I had a lovely old Philco mini-console literally blow up (clouds of
steam nad smoke) while playing away as I worked on something else. Haven't
checked yet to see if the power trans went, but there's black goo all over the
chassis -- want to give it a year to dry out of any toxic stuff.

Then there was the night I left an antique lytic re-forming overnight on my
favorite laboratory variable power supply. It was doing great. Next AM, I
find the cap is still looking great, but the power supply's insides are a
charred mass of clinkers. Enough soot on the ceiling joists to make be
thankful I still had a house to live in.

For the price of a few lattes or a couple of
beers, you can afford to put new electrolytics in your boatanchor and sleep
soundly :-)

Actually, that's more like a couple lattes or a 6-pack of beer, but the point
is well taken! --Mike K.



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

In article , "Frank
Dresser" writes:

Here's the results, checked on a Heathkit IT-28:

Interesting. With very few and small exceptions, every cap measured LESS than
marked. And we thought lytics were being made with very high positive
tolerances, up to 100% or double the value.

I guess you get (almost) what you pay for, no mas! --Mike K.

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

In article . net, "Phil
Nelson" writes:

For a radio that I intend to use regularly, I follow the credo, "kill 'em
all, let God sort them out." Why would you take a chance that a decades-old
electrolytic will survive for another hour, day, or week? You can replace it
as fast as you can test it, and if you guess wrong, it may cost you an
expensive power transformer.

Amen. I had a lovely old Philco mini-console literally blow up (clouds of
steam nad smoke) while playing away as I worked on something else. Haven't
checked yet to see if the power trans went, but there's black goo all over the
chassis -- want to give it a year to dry out of any toxic stuff.

Then there was the night I left an antique lytic re-forming overnight on my
favorite laboratory variable power supply. It was doing great. Next AM, I
find the cap is still looking great, but the power supply's insides are a
charred mass of clinkers. Enough soot on the ceiling joists to make be
thankful I still had a house to live in.

For the price of a few lattes or a couple of
beers, you can afford to put new electrolytics in your boatanchor and sleep
soundly :-)

Actually, that's more like a couple lattes or a 6-pack of beer, but the point
is well taken! --Mike K.



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

"Mike Knudsen" wrote in message
...


Interesting. With very few and small exceptions, every cap measured LESS
than
marked. And we thought lytics were being made with very high positive
tolerances, up to 100% or double the value.

I guess you get (almost) what you pay for, no mas! --Mike K.


I can't be sure the checker isn't just reading low. I do get repeatable and
sensible readings from it.

I also don't know if the caps I checked just by chance happened to be
generally bunched around common values, or if they are actually made with
more precision than they are rated for. It's a small sample.

But modern (maybe even 50 years ago) manufacturing ought to be able to make
a reasonably precise product as long as they are able to stick with a
process that is known to work. I have to figure that the capacitor
manufacturers know what they are doing, they regularly check samples of
their product and can make running changes to hit their target specs with
almost every lot.

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!

Frank Dresser

"Mike Knudsen" wrote in message
...


Interesting. With very few and small exceptions, every cap measured LESS
than
marked. And we thought lytics were being made with very high positive
tolerances, up to 100% or double the value.

I guess you get (almost) what you pay for, no mas! --Mike K.


I can't be sure the checker isn't just reading low. I do get repeatable and
sensible readings from it.

I also don't know if the caps I checked just by chance happened to be
generally bunched around common values, or if they are actually made with
more precision than they are rated for. It's a small sample.

But modern (maybe even 50 years ago) manufacturing ought to be able to make
a reasonably precise product as long as they are able to stick with a
process that is known to work. I have to figure that the capacitor
manufacturers know what they are doing, they regularly check samples of
their product and can make running changes to hit their target specs with
almost every lot.

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!

Frank Dresser

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?