4 Jun
2002
4 Jun
'02
3:52 p.m.
So I'm off to look for a 25L6 tube for my IBM 026. John Lawson says that
the tube is a 25L6 because all the other tubes in the rack are 25L6 types
and he believes they are hammer drivers. Not to doubt the venerable
Mr. Lawson, since he did used to service these, but I just want to make
sure this is in fact the right tube type that goes into the socket that is
currently empty. See photo here:
http://www.vintage.org/gallery.php?title=IBM%20026%20Printing%20Card%20Card…
I'd hate to plug in the wrong tube and then witness volumnious
amounts of smoke billow from within the machine. Can someone verify that
the 25L6 is indeed the correct tube for the empty socket?
Thanks!
Sellam Ismail Vintage Computer Festival
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4 Jun
4 Jun
8:36 p.m.
On Tue, 4 Jun 2002, Sellam Ismail wrote:
So I'm off to look for a 25L6 tube for my IBM 026.
John Lawson says
that the tube is a 25L6 because all the other tubes in the rack are
25L6 types and he believes they are hammer drivers. Not to doubt the
venerable Mr. Lawson, since he did used to service these, but I just
want to make sure this is in fact the right tube type that goes into
the socket that is currently empty. See photo here:
I'm fairly certain it does use a 25L6. According to all the information I
found online, IBM often used them in groups of 6 for counter/multiplier or
driver applications. Without seeing prints, there is no way for me to know
if they used them as drivers or counters, but either way, I doubt the
punch will work very well with a missing tube.
Do the heaters of the other 5 tubes in the same row glow? IBM may have
used 6x 25V heaters in series to avoid using a voltage regulator. If you
find a source for the 25L6, and especially the IBM branded tube, get at
least a couple of extras. Tubes are generally very robust, but they don't
like being jarred around, and theres no telling what kind of abuse the
current tubes have been though.
According to this usenet article from 1995, the 026 used 6 25L6 tubes in a
row as drivers:
http://groups.google.com/groups?as_umsgid=41nefs%241a90%40bigblue.oit.unc.e…
This article states basically the same thing:
http://groups.google.com/groups?as_umsgid=3C194D05.143E4168%40zianet.com
I'd hate to plug in the wrong tube and then
witness volumnious amounts
of smoke billow from within the machine. Can someone verify that the
25L6 is indeed the correct tube for the empty socket?
Well, the tubes are not likely to smoke, but old capacitors are... I'm
guessing that you've already powered the unit up by now, but I'd recommend
using a variac to bring the voltage up slowly when first powering up old
equipment such as this when it has been stored for a long time. Bringing
it up to full voltage slowly allows slow reformation of older caps that
would otherwise fail with a loud 'bang', which would usually take a few
other parts (most often resistors) with them. Note that modern equipment
often does not like this procedure, especially when it uses a SMPSU.
-Toth
5 Jun
5 Jun
4:39 a.m.
Tothwolf wrote:
On Tue, 4 Jun 2002, Sellam Ismail wrote:
Well we have an 026 at ACONIT, I was there today but othe errands got in
the way of checking it out, my next visit is scheduled for Friday and I
will try and remember.
-- hbp
So I'm off to look for a 25L6 tube for my IBM
026. John Lawson says
that the tube is a 25L6 because all the other tubes in the rack are
25L6 types and he believes they are hammer drivers. Not to doubt the
venerable Mr. Lawson, since he did used to service these, but I just
want to make sure this is in fact the right tube type that goes into
the socket that is currently empty. See photo here:
I'm fairly certain it does use a 25L6. According to all the information I
found online, IBM often used them in groups of 6 for counter/multiplier or
driver applications. Without seeing prints, there is no way for me to know
if they used them as drivers or counters, but either way, I doubt the
punch will work very well with a missing tube. 
7:13 a.m.
On Wed, 5 Jun 2002, Hans B Pufal wrote:
Well we have an 026 at ACONIT, I was there today but othe errands got in
the way of checking it out, my next visit is scheduled for Friday and I
will try and remember.
That would be Very Cool!
Just the types and positions would be very helpful - thanks in advance!
I think they're all the same type, but it's better to be certain, rather
than using 'magic smoke' as a determinant. ;}
Cheers
John
Tothwolf wrote:
> On Tue, 4 Jun 2002, Sellam Ismail wrote:
[snippage]
-- hbp
7:46 a.m.
Just the types and positions would be very helpful
- thanks in advance!
I think they're all the same type, but it's better to be certain, rather
than using 'magic smoke' as a determinant. ;}
Cheers
John
If you do a google groups search for:
floyd sense 026 ibm
In the first hit you will find a message by Floyd Sense who states
that he serviced the 026 and that it only used one type of tube.
The complete thread references the 25L6GT IBM branded tube.
7:41 a.m.
Do the heaters of the other 5 tubes in the same row
glow? IBM may have
used 6x 25V heaters in series to avoid using a voltage regulator.
IBM used 25L6 because of the large amount of 24 Volt control systems in
there machines for the relays, timers, solenoids, and so forth.
Basically, it was handy.
Keep in mind that it may be intended that the socket is empty - perhaps
for an option not installed in Sellam's machine.
William Donzelli
aw288(a)osfn.org
10:59 a.m.
On Wed, 5 Jun 2002, Tothwolf wrote:
Do the heaters of the other 5 tubes in the same row
glow? IBM may have
Yes.
used 6x 25V heaters in series to avoid using a voltage
regulator. If you
find a source for the 25L6, and especially the IBM branded tube, get at
least a couple of extras. Tubes are generally very robust, but they don't
like being jarred around, and theres no telling what kind of abuse the
current tubes have been though.
Yeah, if I could find a stash of IBM tubes I would certainly buy them all
:) I'm not holding out for that. A generic tube would suit me fine.
Well, the tubes are not likely to smoke, but old
capacitors are... I'm
guessing that you've already powered the unit up by now, but I'd recommend
using a variac to bring the voltage up slowly when first powering up old
equipment such as this when it has been stored for a long time. Bringing
Yeah, we were impatient. These old machines are tough though. We didn't
have any problems.
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com *
11:34 a.m.
--- Sellam Ismail <foo(a)siconic.com> wrote:
Yeah, if I could find a stash of IBM tubes I would
certainly buy them all
:) I'm not holding out for that. A generic tube would suit me fine.
Me, too. AFAIK, all the tubes in mine are lit, but I'd like to have
some spares. IBM tubes would be nice, but I'll take generic, also.
Yeah, we were impatient. These old machines are tough
though. We didn't
have any problems.
When I got my 026, I didn't know there could _be_ problems. I got lucky,
too. Mine seems to have some mechanical issues - could use a good
cleaning at least.
-ethan
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12:42 p.m.
On Wed, 5 Jun 2002, Ethan Dicks wrote:
--- Sellam Ismail <foo(a)siconic.com> wrote:
Hey Ethan, this is cool!
While there has been a great deal of sage advice, speculation, maybes,
and 'try this' posts concerning the 026 - yours is the first positive
lead.
Would it be possible for you to go pop the back off the machine and give
Sellam and/or the List just a quick note of what tubes are in what
sockets, or, if they are all the same type, could you let us know that
too??
This would remove the nagging doubt caused by no doco and no clear info.
Thanks!!
Cheerz
John
PS: If your machine also uses 25L6s in it, they are common, plentiful, and
cheap - $4 - $7 generally for NOS units.
Yeah, if I could find a stash of IBM tubes I
would certainly buy them all
:) I'm not holding out for that. A generic tube would suit me fine.
Me, too. AFAIK, all the tubes in mine are lit, but I'd like to have
some spares. IBM tubes would be nice, but I'll take generic, also.
9 Jun
9 Jun
2:10 p.m.
--- John Lawson <jpl15(a)panix.com> wrote:
Hey Ethan, this is cool!
While there has been a great deal of sage advice, speculation, maybes,
and 'try this' posts concerning the 026 - yours is the first positive
lead.
Thanks.
Would it be possible for you to go pop the back off
the machine and
give Sellam and/or the List just a quick note of what tubes are in what
sockets, or, if they are all the same type, could you let us know that
too??
I have pictures at:
http://penguincentral.com/retrocomputing/026/Puncher1.jpg
and
http://penguincentral.com/retrocomputing/026/Puncher.jpg
(they were named by a friend's teenaged son who has a better digital
camera than me).
This would remove the nagging doubt caused by no
doco and no clear
info.
To the best of my ability to observe (I did not remove *all* the tubes),
they are all of type 25L6. I did retrieve the docs from the base and
will endeavor to copy them and get copies to Sellam. Most of the pages
are oversized, so it will be a trick.
-ethan
__________________________________________________
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Yahoo! - Official partner of 2002 FIFA World Cup
http://fifaworldcup.yahoo.com
10 Jun
10 Jun
9:54 a.m.
--- John Lawson <jpl15(a)panix.com> wrote:
Hey Ethan, this is cool!
While there has been a great deal of sage advice, speculation,
maybes, and 'try this' posts concerning the 026 - yours is the first
positive lead.
A follow-up: Looking at the notes on the "IBM Wiring Diagram",
number 228005-5, E.C. #203242, "Machine - Printing Card Punch,
Model 026" which I found in the base of mine, there are notes
on the 4th leaf (it's one long folded sheet) in Roman Numerals:
X All tubes are 25L6's
XI All bias resistors are 56K, .5W, part no. 301149
All screen resistors are 4.7K, 1W, part no 169129 unless
otherwise noted
All grid protection resistors are 10K, 1W part no 184093
XII Tube #8 and relay 53 are used only on machines with
comb. keyboards
XIII ----- - - ------ indicates wiring when comb. keyboard used
XIV -- -- -- -- -- indicates wiring when num. keyboard used
XV =====o===== indicates solid bar common
XVI The marked NC terminal on the switch is the terminal
wired as shown
XVII Resistor common not wired as shown
A couple of things: it explicitly says all tubes are "25L6" and that
only tube 8 is optional, depending on configuration. From looking
at the rest of the wiring chart, I can see all the tubes in use
except for 6, the one that Sellam seems to be missing. The tubes
seem to drive various relays thusly:
1 Escape Interlock
2 Release(?)
3 Escape Magnet
4 Skip
5 Dup
6 ?
7 Punch Clutch
8 Alpha Field (with comb. keyboard)
9 Print Sup Magnet
10 Print
No mention of tube 6. :-(
-ethan
__________________________________________________
Do You Yahoo!?
Yahoo! - Official partner of 2002 FIFA World Cup
http://fifaworldcup.yahoo.com
11:27 a.m.
On Mon, 10 Jun 2002, Ethan Dicks wrote:
A follow-up: Looking at the notes on the "IBM
Wiring Diagram",
number 228005-5, E.C. #203242, "Machine - Printing Card Punch,
Model 026" which I found in the base of mine, there are notes
on the 4th leaf (it's one long folded sheet) in Roman Numerals:
X All tubes are 25L6's
XI All bias resistors are 56K, .5W, part no. 301149
All screen resistors are 4.7K, 1W, part no 169129 unless
otherwise noted
All grid protection resistors are 10K, 1W part no 184093
XII Tube #8 and relay 53 are used only on machines with
comb. keyboards
XIII ----- - - ------ indicates wiring when comb. keyboard used
XIV -- -- -- -- -- indicates wiring when num. keyboard used
XV =====o===== indicates solid bar common
XVI The marked NC terminal on the switch is the terminal
wired as shown
XVII Resistor common not wired as shown
A couple of things: it explicitly says all tubes are "25L6" and that
only tube 8 is optional, depending on configuration. From looking
What is the "comb. keyboard"? Combination? At any rate, maybe I can move
tube #8 into the #6 position and play around with it in that configuration
and see what happens.
at the rest of the wiring chart, I can see all the
tubes in use
except for 6, the one that Sellam seems to be missing. The tubes
seem to drive various relays thusly:
1 Escape Interlock
2 Release(?)
3 Escape Magnet
4 Skip
5 Dup
6 ?
7 Punch Clutch
8 Alpha Field (with comb. keyboard)
9 Print Sup Magnet
10 Print
No mention of tube 6. :-(
Bummer. But that is some very solid information. Thanks for posting it.
I should finally have time to track down that tube and replace it this
week.
Sellam Ismail Vintage Computer Festival
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5 Jun
5 Jun
2:16 p.m.
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ard＠p850ug1.demon.co.uk -
aw288＠osfn.org -
erd_6502＠yahoo.com -
foo＠siconic.com -
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