On 12/12/2020 4:49 am, Don wrote:
The earlier Callins link was only for reference to give people an idea
of the price and physical characteristics.

My questions actually pertain to a 100 μF 6 V Callins, which looks
identical. It's used in a PAIA VCO module from the 1970s. The
schematic's shown he

https://crcomp.net/paia/2720-2A.png

C7 is the Callins. C6 is a plain vanilla electrolytic in a can. They
both have a value of 100 μF.

Although the simpleminded answer goes through everyone's mind first, it
doesn't add up. Why pay more for a Callins back in the day? Why not buy
twice as many electrolytics in cans to get a better price break?
Or, if Callins was the cheap alternative back then, why pay more
for electrolytics in cans?

Perhaps the answer's as simple as the late John Simonton inheriting a
pile of Callins. It's too late to ask John, but there's a PAIA forum,
which may supply some answers, provided they process my registration.
For the time being, the Callins will be substituted with a new
electrolytic in a can.

Danke,


I have some similar epoxy sealed aluminum electrolytics from the mid
1970s made by Roederstein (now incorporated into Vishay). At the time
they cost only a few percent more than metal can/elastomer seal
capacitors. There is absolutely nothing special about the electrical
characteristics needed of C6 and C7 in that unsavoury circuit and my
guess is that the assemblers just randomly picked that brand.

piglet

In sci.electronics.design legg wrote:
On Sat, 12 Dec 2020 07:56:15 -0000 (UTC), "Don" wrote:

Phil Allison wrote:

the Callins is in an epoxy sealed container

Interesting, but it doesn't answer my question:

Why was the circuit designed to use a Callins in C7?

If it was designed to use a Callins cap, then Callins
would show up on the schematic and BOM.

As it is, specifying a 6V electrolytic to filter a
6.2V reference is probably a mistake.

Excellent observation! There's actually a 25 V Callins on the board
itself. So, there's definitely a mistake on the schematic.

Danke,

--
Don, KB7RPU
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.

In sci.electronics.design piglet wrote:
On 12/12/2020 4:49 am, Don wrote:
The earlier Callins link was only for reference to give people an idea
of the price and physical characteristics.

My questions actually pertain to a 100 μF 6 V Callins, which looks
identical. It's used in a PAIA VCO module from the 1970s. The
schematic's shown he

https://crcomp.net/paia/2720-2A.png

C7 is the Callins. C6 is a plain vanilla electrolytic in a can. They
both have a value of 100 μF.

Although the simpleminded answer goes through everyone's mind first, it
doesn't add up. Why pay more for a Callins back in the day? Why not buy
twice as many electrolytics in cans to get a better price break?
Or, if Callins was the cheap alternative back then, why pay more
for electrolytics in cans?

Perhaps the answer's as simple as the late John Simonton inheriting a
pile of Callins. It's too late to ask John, but there's a PAIA forum,
which may supply some answers, provided they process my registration.
For the time being, the Callins will be substituted with a new
electrolytic in a can.

Danke,


I have some similar epoxy sealed aluminum electrolytics from the mid
1970s made by Roederstein (now incorporated into Vishay). At the time
they cost only a few percent more than metal can/elastomer seal
capacitors. There is absolutely nothing special about the electrical
characteristics needed of C6 and C7 in that unsavoury circuit and my
guess is that the assemblers just randomly picked that brand.

Thank you for confirming my suspicions. It turns out there's a typo on
the schematic. The actual Callins capacitor on the board is 25 V.

As an aside, perhaps the circuit's relaxation oscillator looked a little
less unsavory back in the hazy 1970s, back when Woz won Bushnell's
bonus to minimize the chip count.

Danke,

--
Don, KB7RPU
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.

In sci.electronics.design Tim Schwartz wrote:
Don,

If you look closely at the photo showing the cap on its side, you'll
see a row of "+" marks, so this is a plain old polarized electrolytic
capacitor, are are both C6 and C7 on the schematic diagram you provided.
Perhaps one of them had been replaced over the units history. One is
marked 100uf/10V and the other 100V/6V, so maybe it is what the
purchasing department was able to get a deal on.

My experience with those encapsulated Callins caps is that they are
awful. I am NOT a fan of changing every electrolytic capacitor over 3
months old, which seems to be popular on internet forums, but I might
make an exception for the Callins caps. A couple of years ago I got a
lot of surplus caps, including dozens of Callins, all of which tested
bad even after being give a while to form up on my trusty Heathkit IT-28
"capacitor checker".

AR and KLH seemed to use quite a few of them in some models.

Maybe they are charging so much because they are the only good ones
left on the planet?

People get nostalgic about all sorts of things. And it's OK with me if
they spend good money to make the object of their obsession a perfect
replica in every way. Some people pay a lot more for questionable fine
art.

It turns out there's a typo on the schematic. The actual Callins part is
rated at 25 V. Regardless, thank you for taking the time to confirm my
suspicions about it.


Danke,

--
Don, KB7RPU
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.

On Fri, 11 Dec 2020 19:31:10 -0500, legg wrote:

On Fri, 11 Dec 2020 08:55:19 -0800,
wrote:

On Fri, 11 Dec 2020 16:13:22 -0000 (UTC), "Don" wrote:

Greetings,

Why do Callins capacitors command such a high premium:

https://richelectronics.co.uk/produc...ow-esr-ol0382b

What's so special about them?

What's a good substitute?

Danke,

Is that a non-polar electrolytic? Looks like two regular caps potted.

What use is a 300 uF non-polar 'lytic?

Crossover network?

I also saw something of a similar value in a Hafler preamp parts list,
(and another smaller value) though I couldn't locate it on the
schematis..

RL

The old bakelite Black Beauty film (or maybe paper?) caps are highly
prized/priced because some people can hear the difference.

If I paid $25 for a 0.022 uF cap, I bet I could hear the difference.

I wonder how many of these sorts of things are Chinese fakes.







--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.

On Sat, 12 Dec 2020 13:25:26 +0100, Arie de Muynck
wrote:

On 2020-12-11 17:55, wrote:
On Fri, 11 Dec 2020 16:13:22 -0000 (UTC), "Don" wrote:

Greetings,

Why do Callins capacitors command such a high premium:

https://richelectronics.co.uk/produc...ow-esr-ol0382b

What's so special about them?

What's a good substitute?

Danke,

Is that a non-polar electrolytic? Looks like two regular caps potted.

What use is a 300 uF non-polar 'lytic?

The second picture (un)clearly shows + + + marking.


I think so. So it's one ordinary cap potted.



--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.

On Sat, 12 Dec 2020 07:56:15 -0000 (UTC), "Don" wrote:

Phil Allison wrote:

the Callins is in an epoxy sealed container

Interesting, but it doesn't answer my question:

Why was the circuit designed to use a Callins in C7?

Danke,

Was it designed that way?

That circuit was barely designed at all. What's it supposed to do?



--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.

On Sat, 12 Dec 2020 09:18:09 -0500, legg wrote:

On Sat, 12 Dec 2020 07:56:15 -0000 (UTC), "Don" wrote:

Phil Allison wrote:

the Callins is in an epoxy sealed container

Interesting, but it doesn't answer my question:

Why was the circuit designed to use a Callins in C7?

Danke,

If it was designed to use a Callins cap, then Callins
would show up on the schematic and BOM.

As it is, specifying a 6V electrolytic to filter a
6.2V reference is probably a mistake.

RL

Lytics usually have a pretty good overvoltage tolerance, and a little
leakage wouldn't do any harm in a power supply filter. It may have
failed by drying out over the years and been replaced by whatever was
handy.





--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.

In sci.electronics.design wrote:
On Sat, 12 Dec 2020 07:56:15 -0000 (UTC), "Don" wrote:

Phil Allison wrote:

the Callins is in an epoxy sealed container

Interesting, but it doesn't answer my question:

Why was the circuit designed to use a Callins in C7?

Was it designed that way?

That circuit was barely designed at all. What's it supposed to do?

Your question restates the gist of this thread.

How can you know the circuit was barely designed at all if you don't
even know what's it supposed to do?

Danke,

--
Don, KB7RPU
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.

On 2020/12/12 8:44 a.m., Don wrote:
In sci.electronics.design legg wrote:
On Sat, 12 Dec 2020 07:56:15 -0000 (UTC), "Don" wrote:

Phil Allison wrote:

the Callins is in an epoxy sealed container

Interesting, but it doesn't answer my question:

Why was the circuit designed to use a Callins in C7?

If it was designed to use a Callins cap, then Callins
would show up on the schematic and BOM.

As it is, specifying a 6V electrolytic to filter a
6.2V reference is probably a mistake.

Excellent observation! There's actually a 25 V Callins on the board
itself. So, there's definitely a mistake on the schematic.

Danke,


Engineers make mistakes? Never!

(ducking)

John :-#)#