29 Apr
2012
29 Apr
'12
6:06 a.m.
According to http://so-much-stuff.com/pdp8/repair/subst.php a D672 crosses
to a 1N3656 diode, which you can (theoretically) get from amazon.com (or
your local flavor thereof)
I would resist the urge to plug something that looks similiar in to see
what happens. You run the risk of damaging something else.
Clint
On Sun, 29 Apr 2012, RobJ wrote:
The saga of my broken PDP11/24 PSU (H7140) continues.
I have now found a
shorted diode and need to find a suitable replacement. On the printset it is
described as "D 672 TR=14NS PIV=60V SI".
What would be a suitable replacement?
There is a local Maplin that would be open today that has this one:
http://www.maplin.co.uk/switching-diode-46386, would that be suitable?
Regards
Rob
29 Apr
29 Apr
6:52 a.m.
Hi
He already has a shorted diode. I don't think
another diode can do any worse.
Dwight
Date: Sun, 29 Apr 2012 07:06:28 -0600
From: cctech at vax-11.org
To: cctech at classiccmp.org
Subject: Re: Replacement Diode
According to http://so-much-stuff.com/pdp8/repair/subst.php a D672 crosses
to a 1N3656 diode, which you can (theoretically) get from amazon.com (or
your local flavor thereof)
I would resist the urge to plug something that looks similiar in to see
what happens. You run the risk of damaging something else.
Clint
On Sun, 29 Apr 2012, RobJ wrote:
> The saga of my broken PDP11/24 PSU (H7140) continues. I have now found a
> shorted diode and need to find a suitable replacement. On the printset it is
> described as "D 672 TR=14NS PIV=60V SI".
>
> What would be a suitable replacement?
>
> There is a local Maplin that would be open today that has this one:
> http://www.maplin.co.uk/switching-diode-46386, would that be suitable?
>
> Regards
>
> Rob
>
7:34 a.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of cctech at vax-11.org
Sent: 29 April 2012 14:06
To: General Discussion: On-Topic Posts Only
Subject: Re: Replacement Diode
According to http://so-much-stuff.com/pdp8/repair/subst.php a D672
crosses to a 1N3656 diode, which you can (theoretically) get from
amazon.com (or your local flavor thereof)
I would resist the urge to plug something that looks similiar in to see
what
happens. You run the risk of damaging something else.
Clint
Thanks for the link, that is really useful, I had not come across it before.
Actually, it shows the 672 to be either a 1N3653 or a 1N3656. I can find
more info on the 3653 than the 3656. The 3653 appears to have a spec
equivalent to or better than what it lists in the parts list.
Now it seems I have to find the modern equivalent of those diodes. A 1N4149
seems to fit the bill, does that seem reasonable? Here is Farnell's
description:
http://uk.farnell.com/fairchild-semiconductor/1n4149/small-signal-diode-0-5a
-do35/dp/1651147
Thanks
Rob
10:09 a.m.
For your description, any 1n400x diode would fit the bill...
---
Enviado do meu Motorola PT550
Meu site: http://www.tabalabs.com.br
----- Original Message -----
From: "Rob Jarratt" <robert.jarratt at ntlworld.com>
To: "'General Discussion: On-Topic and Off-Topic Posts'"
<cctalk at classiccmp.org>; "'General Discussion: On-Topic Posts
Only'"
<cctech at classiccmp.org>
Sent: Sunday, April 29, 2012 11:34 AM
Subject: RE: Replacement Diode
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of cctech at vax-11.org
Sent: 29 April 2012 14:06
To: General Discussion: On-Topic Posts Only
Subject: Re: Replacement Diode
According to http://so-much-stuff.com/pdp8/repair/subst.php a D672
crosses to a 1N3656 diode, which you can (theoretically) get from
amazon.com (or your local flavor thereof)
I would resist the urge to plug something that looks similiar in to see
what
happens. You run the risk of damaging something
else.
Clint
Thanks for the link, that is really useful, I had not come across it
before.
Actually, it shows the 672 to be either a 1N3653 or a 1N3656. I can find
more info on the 3653 than the 3656. The 3653 appears to have a spec
equivalent to or better than what it lists in the parts list.
Now it seems I have to find the modern equivalent of those diodes. A
1N4149
seems to fit the bill, does that seem reasonable? Here is Farnell's
description:
http://uk.farnell.com/fairchild-semiconductor/1n4149/small-signal-diode-0-5a
-do35/dp/1651147
Thanks
Rob
10:42 a.m.
From: cctech at vax-11.org: Sunday, April 29, 2012 6:06 AM
According to
http://so-much-stuff.com/pdp8/repair/subst.php a D672 crosses to
a 1N3656 diode, which you can (theoretically) get from amazon.com (or your
local flavor thereof)
I am glad folks are finding my page useful.
More boards actually cross D672 to 1N3653, though the core memory for
the 8/I and 8/L does suggest the 1N3656 as a substitute.
Looking at the specs, 1N3656 is slower and higher voltage than the 1N3653.
On Sun, 29 Apr 2012, RobJ wrote:
> The saga of my broken PDP11/24 PSU (H7140) continues. I have now found a
> shorted diode and need to find a suitable replacement. On the printset it is
> described as "D 672 TR=14NS PIV=60V SI".
>
> What would be a suitable replacement?
They've called out a speed and a reverse voltage, so I'd guess those are the
critical spec's. Based on that, I'd lean toward the 1N3653 for the replacement.
(That would be 100V and 4ns.)
Someone mentioned 1N400x. The 1N4001 is too low a voltage, and I don't think
any of the 1N400x series are meant as switching diodes. A lot of datasheets for
1N400x don't even give a spec for it. I'd stick with something that is
guaranteed
to be 14ns or better.
Vince
10:58 a.m.
On 04/29/2012 01:42 PM, Vincent Slyngstad wrote:
From: cctech at vax-11.org: Sunday, April 29, 2012
6:06 AM
I certainly am! I just ordered a bunch of bulbs to re-bulb my RL02s
thanks to your info. They arrived a couple of days ago and all is well.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
According to
http://so-much-stuff.com/pdp8/repair/subst.php a D672
crosses to a 1N3656 diode, which you can (theoretically) get from
amazon.com (or your local flavor thereof)
I am glad folks are finding my page useful.
4620
days inactive
4620
days old
5 comments
6 participants
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