On Thu, Jan 6, 2022, 01:20 Joshua Rice via cctech
wrote:
>
> Not cost effective at nearly $10,000! I understand they're very rare,
> given they were only used for a few years in industry and they're
> clocking on 3/4 of a century old, but even then, that seems an order of
> magnitude or two off t
On 1/6/22 6:04 PM, Matt Burke via cctalk wrote:
Quiet regulator: http://www.9track.net/posts/h744/h744_ba11_q2e.png
Noisy regulator: http://www.9track.net/posts/h744/h744_ts11_q2e.png
The yellow trace is the emitter of Q2 (input of L1) and the cyan trace
is the output of L1. Q2 seems to be swit
On Thu, Jan 6, 2022, 08:45 Mike Katz via cctalk
wrote:
> There was also a 1K by 4 version of this tube.
>
I've never seen any info on a 1K*4 Selectron, but they weren't even able to
make the 4K*1 work, and the only production tubes were 256*1.
On 2022-Jan-06, at 4:04 PM, Matt Burke via cctalk wrote:
> On 06/01/2022 12:59, Jonathan Chapman via cctalk wrote:
>> That said, it's not like replacing them with new will *hurt* -- it just
>> might not fix the whine.
>
> I suspect that it won't fix the problem. Slightly hijacking the thread
> he
My 2c. I am not familiar with a "whine" but certainly a "hum." Sometimes if a
power supply has seen a lot of heavy load over its lifetime, the heat generated
can begin to do things to the transformer. And once that heat has done its
"thing" to the transformer, it stays that way. And no replacing
On 06/01/2022 12:59, Jonathan Chapman via cctalk wrote:
> That said, it's not like replacing them with new will *hurt* -- it just might
> not fix the whine.
I suspect that it won't fix the problem. Slightly hijacking the thread
here but hopefully in a semi-helpful way.
I have two of these regula
Bill Whitson, the original ClassicCmp ListOp, has a surprisingly little amount
of information available about him online. Does anyone know what happened to
him after the late 90s? (If anyone has any contact information, that would be
nice!)
Ryan Ottignon
It would be a lot easier to replace the large circular regulator if you're
taking the shotgun approach, and much more likely that the regulator is a
source of faults. and it's cheaper. For the h744, 45, 54. BUT measuring
things is the best way if you can do it. Pull the values from the
backpla
> On Jan 6, 2022, at 2:11 PM, Chuck Guzis via cctalk
> wrote:
>
> On 1/6/22 10:17, William Donzelli wrote:
>> If you include prototypes, then you need to include ALL the prototypes
>> - even things made in single quantities that never worked.
>>
>> That is a HUGE amount of stuff that makes E
On 1/6/22 10:17, William Donzelli wrote:
> If you include prototypes, then you need to include ALL the prototypes
> - even things made in single quantities that never worked.
>
> That is a HUGE amount of stuff that makes EBAM look gigantic.
To be fair, EBAM received a not-insignificant amount of
Prototypes don't count.
--
Will
On Thu, Jan 6, 2022 at 12:41 PM Chuck Guzis via cctech
wrote:
>
>
> Perhaps even rarer were the EBAM tubes that CDC worked with during the
> 1970s. I recall seeing a 6' rack of a complete assembly sitting in a
> hallway at ADL around 1974. If CDC followed the di
Perhaps even rarer were the EBAM tubes that CDC worked with during the
1970s. I recall seeing a 6' rack of a complete assembly sitting in a
hallway at ADL around 1974. If CDC followed the dictates of management
then, the unit was probably utterly demolsihed before being sold as
scrap metal.
--
On 1/6/22 2:52 AM, Rob Jarratt via cctalk wrote:
I think I may need to replace the two output capacitors in some of my H744
regulators. These are screw terminal 6,000uF 10V parts. I have looked on
Mouser, Farnell and Digikey and there don't seem to be any available, and
any that are listed are re
There was also a 1K by 4 version of this tube.
On 1/6/2022 3:03 AM, Brent Hilpert via cctalk wrote:
On 2022-Jan-06, at 12:19 AM, Joshua Rice via cctech wrote:
Not cost effective at nearly $10,000! I understand they're very rare, given
they were only used for a few years in industry and they're
> On Jan 6, 2022, at 4:06 AM, Brent Hilpert via cctalk
> wrote:
>
> On 2022-Jan-06, at 12:19 AM, Joshua Rice via cctech wrote:
>> Not cost effective at nearly $10,000! I understand they're very rare, given
>> they were only used for a few years in industry and they're clocking on 3/4
>> of
> -Original Message-
> From: cctalk On Behalf Of Peter Coghlan
> via cctalk
> Sent: 06 January 2022 12:16
> To: General Discussion: On-Topic and Off-Topic Posts
>
> Subject: RE: Source for replacement caps in H744 regulators
>
>
> >
> >> -Original Message-
> >> From: cctalk
> -Original Message-
> From: Jonathan Chapman
> Sent: 06 January 2022 13:00
> To: r...@jarratt.me.uk; Rob Jarratt ; General
> Discussion: On-Topic and Off-Topic Posts
> Subject: RE: Source for replacement caps in H744 regulators
>
> > One of the H744 regulators whines
>
> FWIW, none of
>
>> -Original Message-
>> From: cctalk On Behalf Of Christian Corti
>> via cctalk
>> Sent: 06 January 2022 10:02
>> To: General Discussion: On-Topic and Off-Topic Posts
>>
>> Subject: Re: Source for replacement caps in H744 regulators
>>
>> On Thu, 6 Jan 2022, r...@jarratt.me.uk wrote
> One of the H744 regulators whines
FWIW, none of mine are silent under load. If they're not being loaded (e.g. on
a test bench, with no dummy load, or if you have all the boards out) they can
whine excessively due to no minimum load.
> it seems higher than the expected values printed on the me
> -Original Message-
> From: cctalk On Behalf Of Christian Corti
> via cctalk
> Sent: 06 January 2022 10:02
> To: General Discussion: On-Topic and Off-Topic Posts
>
> Subject: Re: Source for replacement caps in H744 regulators
>
> On Thu, 6 Jan 2022, r...@jarratt.me.uk wrote:
> > If I
Rob,
The voltage rating is just an absolute maximum. For PSU capacitors the other
critical rating is ripple current. Lower voltages are
The capacitance value won't be too critical either. At the time that was
made typical electrolytic tolerances were -50/+100%
So your 6,000uf could be anywhere be
On Thu, 6 Jan 2022, r...@jarratt.me.uk wrote:
If I can't find 10V rated ones, then, generally up to what sort of voltage
rating can I go? Of course, physical size will be a factor, but electrically
can it affect operation of the regulator if the rated voltage is too high?
If you need to ask thi
On 06/01/2022 08:52, Rob Jarratt via cctalk wrote:
> I think I may need to replace the two output capacitors in some of my H744
> regulators. These are screw terminal 6,000uF 10V parts. I have looked on
> Mouser, Farnell and Digikey and there don't seem to be any available, and
> any that are liste
On 2022-Jan-06, at 12:19 AM, Joshua Rice via cctech wrote:
> Not cost effective at nearly $10,000! I understand they're very rare, given
> they were only used for a few years in industry and they're clocking on 3/4
> of a century old, but even then, that seems an order of magnitude or two off
>
Not cost effective at nearly $10,000! I understand they're very rare,
given they were only used for a few years in industry and they're
clocking on 3/4 of a century old, but even then, that seems an order of
magnitude or two off the real value.
Actually, looking them up, doesn't seem they wer
On 2022-Jan-06, at 12:19 AM, Joshua Rice via cctech wrote:
> Not cost effective at nearly $10,000! I understand they're very rare, given
> they were only used for a few years in industry and they're clocking on 3/4
> of a century old, but even then, that seems an order of magnitude or two off
>
I think I may need to replace the two output capacitors in some of my H744
regulators. These are screw terminal 6,000uF 10V parts. I have looked on
Mouser, Farnell and Digikey and there don't seem to be any available, and
any that are listed are really rather costly.
Does anyone know where I mi
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