CK722 Fans

  • Thread starter Watson A.Name - \"Watt Su
  • Start date
W

Watson A.Name - \"Watt Su

Guest
Seems to be a pent-up demand for those ol' timers, that just can't seem
to be quenched. Always someone who's willing to pay exhorbitant prices
for the nearly useless critters. There were three up for bid this week
on Ebay, starting at $15 and buy it now for $30. Last I checked, they
were all spoken for. Unfortunately I had to delete them from my items
i'm watching and I don't have the item numbers. But the picture showed
them sticking out of a DMM that had the transistor checker and the DMM
read somethig like 77 for the gain, so they were apparently working.
But they all looked like they had short leads, so presumably they were
all pulls or from an experimenter's junque box. Who know what kind of
abuse they had been subjected to?

I still have a datasheet for the 2N107, which was GE's answer to the
CK722. I don't think it was ever as popular, and I don't remember what
the price was or which was cheaper. But according to the GE manual, 4th
Ed., the 2N107 and its NPN sister the 2N170 were rated for Vce= -12V,
IC= 10mA and 50mW (107) and 6V, 20mA and 25mW (170). I don't think the
CK722 was much better. Neither of my two substitution manuals from the
early '60s has the CK722, so I don't have an authoritative source. If
someone has a datasheet or other reference for the CK722, please post
it. Thanks.


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
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Don't be ripped off by the big book dealers. Go to the URL
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Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
 
In article <118ujv6fq33s4de@corp.supernews.com>,
"Watson A.Name - \"Watt Sun, the Dark Remover\""
<NOSPAM@dslextreme.com> wrote:

Seems to be a pent-up demand for those ol' timers, that just can't seem
to be quenched. Always someone who's willing to pay exhorbitant prices
for the nearly useless critters. There were three up for bid this week
on Ebay, starting at $15 and buy it now for $30. Last I checked, they
were all spoken for. Unfortunately I had to delete them from my items
i'm watching and I don't have the item numbers. But the picture showed
them sticking out of a DMM that had the transistor checker and the DMM
read somethig like 77 for the gain, so they were apparently working.
But they all looked like they had short leads, so presumably they were
all pulls or from an experimenter's junque box. Who know what kind of
abuse they had been subjected to?

I still have a datasheet for the 2N107, which was GE's answer to the
CK722. I don't think it was ever as popular, and I don't remember what
the price was or which was cheaper. But according to the GE manual, 4th
Ed., the 2N107 and its NPN sister the 2N170 were rated for Vce= -12V,
IC= 10mA and 50mW (107) and 6V, 20mA and 25mW (170). I don't think the
CK722 was much better. Neither of my two substitution manuals from the
early '60s has the CK722, so I don't have an authoritative source. If
someone has a datasheet or other reference for the CK722, please post
it. Thanks.
Click to expand...
CK722

PDmax = 4 milliwatt
BV(cbo) = 22V
Ic max = 10mA
hfe = 30 (test condition unknown)

Extracted from the 1987 D.A.T.A.Book edition 57

I have a few. Why do I want them? Nostalgia! I wish I still had the
super regen AM radio I built with my CK722 and CK768 in the 50's. If I
could find a copy of the schematic, I would try to duplicate it. I still
have some AM loopsticks from the 50's. Jeez, do I have a lot of junk in
my basement!

Al
 
After my first real summer job in 1955 working on a CNR steel relay gang in
BC I stopped in Edmonton and bought two CK722s and a Weller soldering gun.
I still have the gun and it works great. IIRC the two CK722s cost more than
the gun. When I got home I started building an audio amp for my xtal set
and one of the leads just broke off right at the case and I didn't
mishandle it. I was finally able to a tack a lead back on. I then mounted
the transistors on a separate pieces of wood and soldered the leads to
fahenstock clips. Those 2 are long gone but I did find one in a junk box at
a hamfest for free. I'm still a little hesitant to put it to use for fear a
lead might break off. I've heard that germanium transistors don't age well
and some kind of migration degrades their specs.

--

73
Hank WD5JFR
"Watson A.Name - "Watt Sun, the Dark Remover"" <NOSPAM@dslextreme.com> wrote
in message news:118ujv6fq33s4de@corp.supernews.com...
Seems to be a pent-up demand for those ol' timers, that just can't seem
to be quenched. Always someone who's willing to pay exhorbitant prices
for the nearly useless critters. There were three up for bid this week
on Ebay, starting at $15 and buy it now for $30. Last I checked, they
were all spoken for. Unfortunately I had to delete them from my items
i'm watching and I don't have the item numbers. But the picture showed
them sticking out of a DMM that had the transistor checker and the DMM
read somethig like 77 for the gain, so they were apparently working.
But they all looked like they had short leads, so presumably they were
all pulls or from an experimenter's junque box. Who know what kind of
abuse they had been subjected to?

I still have a datasheet for the 2N107, which was GE's answer to the
CK722. I don't think it was ever as popular, and I don't remember what
the price was or which was cheaper. But according to the GE manual, 4th
Ed., the 2N107 and its NPN sister the 2N170 were rated for Vce= -12V,
IC= 10mA and 50mW (107) and 6V, 20mA and 25mW (170). I don't think the
CK722 was much better. Neither of my two substitution manuals from the
early '60s has the CK722, so I don't have an authoritative source. If
someone has a datasheet or other reference for the CK722, please post
it. Thanks.


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
Click to expand...
 
Henry Kolesnik wrote:

After my first real summer job in 1955 working on a CNR steel relay gang in
BC I stopped in Edmonton and bought two CK722s and a Weller soldering gun.
I still have the gun and it works great. IIRC the two CK722s cost more than
the gun. When I got home I started building an audio amp for my xtal set
and one of the leads just broke off right at the case and I didn't
mishandle it. I was finally able to a tack a lead back on. I then mounted
the transistors on a separate pieces of wood and soldered the leads to
fahenstock clips. Those 2 are long gone but I did find one in a junk box at
a hamfest for free. I'm still a little hesitant to put it to use for fear a
lead might break off. I've heard that germanium transistors don't age well
and some kind of migration degrades their specs.



Hmmm, could be. I overhauled an HP synthesizer from the 1960's that
Click to expand...
must have had
100 Germainum transistors in it. There must have been 10 dead ones. I
found one
of the Motorola UHF silicon transistors (I forget, either MPSH10 or MPSH81)
seemed to be a drop-in replacement for them. I did get it working, but
it took way too
much time. (This unit was definitely a decade later than the CK722
vintage transistors.)

Jon
 
Jon Elson wrote:

Henry Kolesnik wrote:

After my first real summer job in 1955 working on a CNR steel relay
gang in BC I stopped in Edmonton and bought two CK722s and a Weller
soldering gun. I still have the gun and it works great. IIRC the two
CK722s cost more than the gun. When I got home I started building an
audio amp for my xtal set and one of the leads just broke off right at
the case and I didn't mishandle it. I was finally able to a tack a
lead back on. I then mounted the transistors on a separate pieces of
wood and soldered the leads to fahenstock clips. Those 2 are long
gone but I did find one in a junk box at a hamfest for free. I'm
still a little hesitant to put it to use for fear a lead might break
off. I've heard that germanium transistors don't age well and some
kind of migration degrades their specs.



Hmmm, could be. I overhauled an HP synthesizer from the 1960's that
must have had
100 Germainum transistors in it. There must have been 10 dead ones. I
found one
of the Motorola UHF silicon transistors (I forget, either MPSH10 or MPSH81)
seemed to be a drop-in replacement for them. I did get it working, but
it took way too
much time. (This unit was definitely a decade later than the CK722
vintage transistors.)

Jon
Click to expand...
Recently, i have repaired an old frequency divider (hp 5260A)
from the mid/end of the sixties, in which a lot of
silicon transistors (2N3904) all has lost their emitters (went open
circuit, only remained a diode function from base to collector)...
interestingly, nearly all transistors that i have found to be defectife
due to aging process (not due to a suddenly hefty overload) went gone
open emitter...

Jorgen
dj0ud
 
"Jon Elson" <jmelson@artsci.wustl.edu> wrote in message
news:42920CBA.1040808@artsci.wustl.edu...
Henry Kolesnik wrote:

After my first real summer job in 1955 working on a CNR steel relay
gang in
BC I stopped in Edmonton and bought two CK722s and a Weller soldering
gun.
I still have the gun and it works great. IIRC the two CK722s cost
more than
the gun. When I got home I started building an audio amp for my xtal
set
and one of the leads just broke off right at the case and I didn't
mishandle it. I was finally able to a tack a lead back on. I then
mounted
the transistors on a separate pieces of wood and soldered the leads
to
fahenstock clips. Those 2 are long gone but I did find one in a junk
box at
a hamfest for free. I'm still a little hesitant to put it to use for
fear a
lead might break off. I've heard that germanium transistors don't
age well
and some kind of migration degrades their specs.



Hmmm, could be. I overhauled an HP synthesizer from the 1960's that
must have had
100 Germainum transistors in it. There must have been 10 dead ones.
I
found one
of the Motorola UHF silicon transistors (I forget, either MPSH10 or
MPSH81)
seemed to be a drop-in replacement for them. I did get it working,
but
it took way too
much time. (This unit was definitely a decade later than the CK722
vintage transistors.)

Jon
Click to expand...
Well, let us know which model that might be so we can avoid that one in
the future. [:)
 
Watson A.Name - "Watt Sun, the Dark Remover" wrote:

"Jon Elson" <jmelson@artsci.wustl.edu> wrote in message
news:42920CBA.1040808@artsci.wustl.edu...


Henry Kolesnik wrote:


After my first real summer job in 1955 working on a CNR steel relay

gang in

BC I stopped in Edmonton and bought two CK722s and a Weller soldering

gun.

I still have the gun and it works great. IIRC the two CK722s cost

more than

the gun. When I got home I started building an audio amp for my xtal

set

and one of the leads just broke off right at the case and I didn't
mishandle it. I was finally able to a tack a lead back on. I then

mounted

the transistors on a separate pieces of wood and soldered the leads

to

fahenstock clips. Those 2 are long gone but I did find one in a junk

box at

a hamfest for free. I'm still a little hesitant to put it to use for

fear a

lead might break off. I've heard that germanium transistors don't

age well

and some kind of migration degrades their specs.




Hmmm, could be. I overhauled an HP synthesizer from the 1960's that
must have had
100 Germainum transistors in it. There must have been 10 dead ones.

I

found one
of the Motorola UHF silicon transistors (I forget, either MPSH10 or

MPSH81)

seemed to be a drop-in replacement for them. I did get it working,

but

it took way too
much time. (This unit was definitely a decade later than the CK722
vintage transistors.)

Jon


Well, let us know which model that might be so we can avoid that one in
the future. [:)
Click to expand...

I expect the synthesizecould be the 5100's series
(5100A, 5105A, 5110A Synth. Driver) which in fact contains a whole lot
of old germaniums. And step recovery diodes which
also are made of unobtainium ;-) (similarly seldom as tunnel diodes)

Jorgen
 
"Henry Kolesnik" <kolesnik@sbcglobal.net> wrote in message
news:7j2ke.42$TJ2.18@newssvr11.news.prodigy.com...
After my first real summer job in 1955 working on a CNR steel relay
gang in
BC I stopped in Edmonton and bought two CK722s and a Weller soldering
gun.
I still have the gun and it works great. IIRC the two CK722s cost
more than
the gun. When I got home I started building an audio amp for my xtal
set
and one of the leads just broke off right at the case and I didn't
mishandle it. I was finally able to a tack a lead back on. I then
mounted
the transistors on a separate pieces of wood and soldered the leads
to
fahenstock clips. Those 2 are long gone but I did find one in a junk
box at
a hamfest for free. I'm still a little hesitant to put it to use for
fear a
lead might break off. I've heard that germanium transistors don't age
well
and some kind of migration degrades their specs.

--

73
Hank WD5JFR
Click to expand...
After awhile the makers determined that since germanium couldn't be
passivated like silicon, it was a Really Good Idea to put them in a
hermetically sealed package, such as the TO-5, and later occasionally
TO-18. But apparently the Raytheon manufacturing process was clean
enough to allow those CKs to be in a package sealed with epoxy or some
plastic, and still not get contaminated over the years. But a lot of
the CKs were knockoffs from somewhere else or else rejects, and were
destined to suffer some degradation over time. Their performance is so
mediocre that they really aren't worth anything today except for
collecible value.

And they certainly seem to be in demand by collectors. I should put the
half dozen or so that I have up for sale on Ebay, but I don't really
need the money that bad. I think I would be better off liquidating the
stam collection that I have from when I was a kid; it could bring a few
thou. But the prices of commemoratives don't seem to have gone up by
more than 10 to 25% of their face value. So I don't think I'd be making
minimum wage. :-(


"Watson A.Name - "Watt Sun, the Dark Remover"" <NOSPAM@dslextreme.com
wrote
in message news:118ujv6fq33s4de@corp.supernews.com...

Seems to be a pent-up demand for those ol' timers, that just can't
seem
to be quenched. Always someone who's willing to pay exhorbitant
prices
for the nearly useless critters. There were three up for bid this
week
on Ebay, starting at $15 and buy it now for $30. Last I checked,
they
were all spoken for. Unfortunately I had to delete them from my
items
i'm watching and I don't have the item numbers. But the picture
showed
them sticking out of a DMM that had the transistor checker and the
DMM
read somethig like 77 for the gain, so they were apparently working.
But they all looked like they had short leads, so presumably they
were
all pulls or from an experimenter's junque box. Who know what kind
of
abuse they had been subjected to?

I still have a datasheet for the 2N107, which was GE's answer to the
CK722. I don't think it was ever as popular, and I don't remember
what
the price was or which was cheaper. But according to the GE manual,
4th
Ed., the 2N107 and its NPN sister the 2N170 were rated for
Vce= -12V,
IC= 10mA and 50mW (107) and 6V, 20mA and 25mW (170). I don't think
the
CK722 was much better. Neither of my two substitution manuals from
the
early '60s has the CK722, so I don't have an authoritative source.
If
someone has a datasheet or other reference for the CK722, please
post
it. Thanks.
Click to expand...
 
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