Date   
Re: Tek 533 -150 test point

Rajesh VS
 

http://w140.com/tekwiki/images/e/e1/070-0258-00.pdf

Page 62 shows the location, not sure if the terminals are marked or not.

OR you can use the body of the main filter capacitor for -150V (after
removing the protective sleeve)

You are correct, -150V is the reference for all, if you adjust it, rest all
will follow. Details in the manual above. Check calibration section.

HTH
Rajesh

On Wed, Jan 15, 2020 at 2:31 PM N7QL <n7ql.us@...> wrote:

Since I do not see this test point labeled can anyone tell me where it is?
Do I need to adjust it by reading the +100 until it reaches +100? I see
where the -150 adjust pot is at least. I did take some readings of the
other supplies and got low to very low readings from them. I cleaned the
chassis so there would be no dirt. I have my suspicions but I need to know
that the -150 supply is right first. Thank you.



--
/Rajesh

Re: What Tektronix means to me

Abc Xyz
 

Dennis,

I'm curious...of all the Scopes you have been exposed to you say the 7854
is your Favorite. Why is that?

JR

On Thu, Jan 16, 2020, 12:57 PM Dennis Tillman W7PF <@Dennis_Tillman_W7PF>
wrote:

Hi Jim,
The job offer letter from Tektronix is laminated on a plaque where it sits
on my wall along side my diplomas. No. I never went to work at Tek. But in
a way I got to become an honorary member of Tek.

I have been embraced by everyone I meet that is a current or ExTek
employee. I have been included in their private mail reflector, I have been
a member of the vintageTEK Museum since before it opened when Stan
Griffiths first took me over to see the empty store front that would soon
be its first home.

The biggest surprise was when Michael Dunn asked me to take over as
moderator of TekScopes. Why me?

Usually 4 times a year I am in Beaverton visiting my Tek friends. Somehow
one of the most famous design engineers at Tek heard about me several years
ago and quite by accident I introduced myself to him at the museum. He
replied "You're Dennis Tillman!" which stunned me. He is now one of my best
friends. He is so highly regarded among ex-Tek employees that I will often
call him to arrange a lunch with someone at Tek that was legendary. They
never refuse. I have had many fascinating lunches with the people I might
have known if I had become a Tek employee. We often met for lunch in the
Tek cafeteria. Tek closed the cafeteria last month so I'm not sure where we
will have those lunches next.

My favorite scope is the 7854. When I mentioned this to Deane Kidd at a
swap meet one day he said the 7854 project manager was in the next room
having a bite to eat and he introduced me to him. A few days later I asked
him to autograph the cover of my 7854. He was puzzled why I would want his
autograph.

Asking for autographs was something I had started to do when I was at
Microsoft. For each Software Developer Conference I held I asked all the
speakers to autograph their section of the conference notebooks. Bill Gates
and Steve Ballmer's signatures are in them as are all the Windows
developers and many of the famous software developers of the mid-1980s that
attended the conferences.

By now that 7854 cover is so full of autographs of ex-Tek employees that I
have had to switch to the other cover. When I'm all done with the covers I
will give them to the 7854 Project Manager who is now a good friend of mine
that I see every time I'm at a swap meet.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Jim
Ford
Sent: Thursday, January 16, 2020 6:48 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] What Tektronix means to me

Hey, don't keep us in suspense, Dennis! Did you ever get to work for
Tek?Jim Ford Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Dennis Tillman W7PF <
@Dennis_Tillman_W7PF> Date: 1/15/20 10:36 PM (GMT-08:00) To:
TekScopes@groups.io Subject: Re: [TekScopes] What Tektronix means to me
Hi Harvey,Yes, there is no simple solution to things being too far away but
saying "I never expect to go there" (to the Tek Museum) is not the best way
to start out if your goal is to get there. You never know what you ae
capable of until you try. On more than one occasion I decided to hitch hike
cross country from New Jersey to LA and up to San Francisco. Along the way
I stopped at the St. Louis Gateway Arch, Grand Canyon, Mt Palomar to see
the telescope, and the meteor crater in Arizona. On another trip down to
the Keys I stopped at the new Disney World in Orlando. I've been to Mardi
Gras three times.I had an offer to join Tek in 1968 when I was starting my
junior year in college. But they recommended that I get my degree first and
assured me that the job would still be there when I did. Life took me in a
different direction by the time I got my BS E.E. degree. For the next 20
years I regretted that mistake. Instead I moved into a beach front
apartment on the New Jersey shore and, to my surprise, I became a stained
glass artist and beach comer and I went back to college, this time for a BA
in Fine Arts. When I first heard it was possible to build a computer (a
childhood dream of mine) I changed direction again and began building my
own S-100 microcomputer. There were very few people doing that so I quickly
found a job working on microcomputers. Eventually I became frustrated
because I didn't understand software. That became my next challenge. Once I
learned microcomputer programming I thought it would be smart to broaden my
computer background with some mainframe experience. When I tried to do that
I found out very few head hunters even knew what a microcomputer was. They
were focused on filling the thousands of jobs available in the mainframe
world. So I spent the next 6 months trying to get a mainframe job with no
success. Eventually I was hired by an IBM 370 based time sharing company
which saw there was an opportunity linking microcomputers to mainframes.
That exposed me to IBM's premier operating system: Multiple Virtual Systems
(MVS) and the many different IBM operating systems and applications that
worked under MVS. Three years later someone recommended me for a job with
Digital Research, the creator of CP/M (which I knew well), the industry
standard 8-bit OS on microcomputers. Four years later that led to a job at
Microsoft which I was desperate to get because it would finally bring me to
the Pacific Northwest (Tektronix territory) where I would have been 20
years earlier if I had joined Tek. After 3 years at Microsoft it became
clear I had the wrong background. They had their pick of graduating
students with an MS in Computer Science or an MBA. So I went back to
college a third time for an MS in Software Engineering. While I was getting
that degree, Microsoft went from 500 people which was small enough that I
knew almost everyone too many thousands of people. I don't like big
companies and there were other opportunities for me now that I had an MS
S.E.If you are on the other side of the earth and looking at a very small
map it may appear that Microsoft (a few miles from Seattle), and Tektronix
(a few miles from Portland) are right next to each other. It is a boring 3
1/2 hour trip to get there. Sphere Research is more than twice as far. On
more than one occasion I decided to hitch hike cross country from New
Jersey to LA and up to San Francisco. Along the way I stopped at the St.
Louis Gateway Arch, Grand Canyon, Mt Palomar (to see the telescope), and
the meteor crater in Arizona. On another trip down to the Keys and Key West
I stopped at the new Disney World in Orlando. I've been to Mardi Gras three
times. You shouldn't say things like I never expect to get there. It sounds
like you really want to go. If you can make it to Seattle you have a place
to stay with us. Portland is a train ride away. Beaverton is accesable by
light rail from Portland. Dennis Tillman W7PF-----Original
Message-----From: TekScopes@groups.io [mailto:TekScopes@groups.io] On
Behalf Of Harvey WhiteSent: Wednesday, January 15, 2020 5:28 PMTo:
TekScopes@...: Re: [TekScopes] What Tektronix means to meI
understand what you say, parallel to an extent, not congruent
experiences.The Tek museum is 3000 miles from me, and I never expect to go
there.Might we have something on the east coast?(and yes, I'm annoyed that
Sphere's "free" days are even further fromme.) Still would like to find a
214 vertical amplifier board because mine has a bad channel A attenuator,
not that I've asked before.)HarveyOn 1/15/2020 5:15 PM, Dennis Tillman W7PF
wrote:> Like everyone here I have created a problem my wife will have to
deal with when I am no longer around. She has the phone number of the
vintageTEK Museum on our refrigerator. Problem solved.>> Now that that's
out of the way I'm not concerned with recyclers and what will come of my
stuff. I plan on enjoying the afterlife with a Tek 214 portable dual-trace
storage scope in my coffin. The Egyptians had the right idea. Take what you
can with you when you go.>> Tektronix gives me a reason to get up every
day. I can explore anything in electronics with the instruments they
designed. I am the beneficiary of the legacy of Tektronix; the standard of
excellence they strove for; and the support they provided for their
products.>> IN 1967 I bought my first Tek scope, a 453, new for $2,000.
What I learned in the next two years by using that scope every night
propelled me to the top of my class. That was the best investment I ever
made. Tektronix instruments were investments in my future. 10 years later I
bought a 7704A / 7A26 / 7B80 / 7B85 and a pair of P6106 probes for $7,000.
I went into debt to do this because I knew it would pay off for me just
like my 453 had. Two years later I bought a 7D01 / DF2 / DL2 for another
$4,000 to study microcomputers. I eagerly learned microcomputer assembly
language to control the microcomputer hardware I was designing. The next 10
years I had a very rewarding career in microcomputers, mainframes,
operating systems, and software marketing.>> Several totally unexpected
things happened starting in the late 1990s that were to enrich my life yet
again. EBay gave me a way to buy all of the Tektronix instruments I could
never afford back in the 1970s. In 2000 Michael Dunn started TekScopes and
I joined 2 years later. Suddenly I was not alone. I had a vast resource of
expertise to help me fix all the Tek instruments I was buying on eBay. 10
years ago Stan Griffiths and Ed Sinclair started the vintageTEK Museum as a
showcase for all the things Tektronix had made possible. The museum is
preserving the Tek legacy for the benefit of all of us. Last but not least
we have our own specialized Wikipedia. TekWiki has become THE professional
repository of Tektronix documents thanks to the tireless work of Kurt
Rosenfeld. Working long hours alone, into the night, feeding every Tek
document he can find into scanners. He has single-handedly assembled those
papers, manuals, photographs, and comments into a beautiful, easy to use,
library at our finger tips. TekWiki is every bit that is the rival of
Wikipedia.>> I'm too busy using my collection of Tek instruments to dwell
on what will happen to it someday. Because of Tektronix, eBay, TekScopes,
the vintageTEK museum, and TekWiki my life is never dull when a Tektronix
scope is within arm's reach.>> Dennis Tillman W7PF>>>-- Dennis Tillman
W7PFTekScopes Moderator





--
Dennis Tillman W7PF
TekScopes Moderator



Re: Tektronix 532 LV rail shorted

Rajesh VS
 

Hey Randy,
The thing that caused me to suspect the rectifier tube sockets is that
now there is no voltage reaching C640 at all. So I will check them as well.
May be you wanna check R605 first, if its good, you may wanna check if the
transformer wingdings for -150V to see if you are getting AC out from the
transformer and so on.

Follow the signal path as per the schematic so that you can trace and
identify potential failure points and confirm it before removing the
sockets.

Not suggesting but sharing one method I use, which is to spend 80% of the
time analyzing the Symptom | problem on the schematic, and 19 % time doing
measurements to confirm the assumptions and only 1% is spent on working
with a hot soldering iron removing stuff.

Thanks,
Rajesh


On Thu, Jan 16, 2020 at 8:13 AM <randolphbeebe@...> wrote:

Thanks Gentlemen, I will put it back on my bench and follow your
suggestions. Also, I downloaded the "Circuit Concepts" Tekwiki publication
and will read that as well as the 532 circuit description in the manual as
John suggested. I am in the process of putting together an electrical
work bench as a hobby and can navigate simpler circuits but the fact is I
do not quite understand complex interrelationships of the 532 power supply.

The thing that caused me to suspect the rectifier tube sockets is that now
there is no voltage reaching C640 at all. So I will check them as well.

Best,

Randy




--
/Rajesh

Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

 

Hi Wayne,
Thank you for wanting to contribute. We have enough already.
I will print the complete results later today after I have a meeting with Michael Dunn to decide how we want to proceed.
Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Wayne0573 via Groups.Io
Sent: Thursday, January 16, 2020 10:22 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

Have been pretty sick and didn't see this thread until just now. Would be happy to contribute, but it's apparently too late. THANK YOU, Dennis for coordinating this and I'm sorry I wasn't able to get in on it. If you can still accept donations for next year, please let me know!

Thanks,

Wayne





--
Dennis Tillman W7PF
TekScopes Moderator

Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

Wayne0573@...
 

Have been pretty sick and didn't see this thread until just now. Would be happy to contribute, but it's apparently too late. THANK YOU, Dennis for coordinating this and I'm sorry I wasn't able to get in on it. If you can still accept donations for next year, please let me know!

Thanks,

Wayne

Re: Trying to bring back a AA501

Rick Bale
 

Eric, what is the basic criteria needed to be sure the swapped device will work? From all the steps you’ve taken with this resurrection so far, I think you know how to assess the swap.

Re: FS: letter-series plug-in connector, concentric knobs

StefanS
 

Hello Brad,

I am in need of such a blue plugin connector, the one on my 1L5 plugin is broken.
If you are willing to send it to Germany (I am ready to pay extra postage fee), please contact me directly under ssans<_AT_> freenet< _DOT_ >de

--
Stefan

Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

 

Hi Larry,
As many of those other posts in you summary would have mentioned, Groups.io masks email addresses to prevent SPAMbots from harvesting our email account names. So my email address which I listed twice in my post was changed to something that didn't work. It caused a lot of confusion.

By now I have received more than enough in contributions so you should not make any further attempt to send a contribution.
Thank you for being so persistent.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Lawrance A. Schneider
Sent: Thursday, January 16, 2020 9:09 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

Hello Mr. Tillman,

I have tried: Dennis Tillman W7PF
@Dennis–Tillman_W7PF
<@Dennis–Tillman_W7PF>
no caps
I can't remember there permutations I've tried a the moment, but each has failed to pass muster : Please enter a valid email address, name or mobile number (i.e. name@..., a name or 10 digit number only).

I would be more than happy to contribute!! What have I done wrong.
-----------
Further, I got this original missive this morning 16 Jan 20 .Why the delay??
I choose to get the group as conglomerate rather than individual missives.

Thank you Mr. Tillman for your efforts.

If you still need more money, I'll try snail mail.

Very gratefully, larry





--
Dennis Tillman W7PF
TekScopes Moderator

Re: Tek 604: Sad story, and CRT wanted

John Griessen
 

On 1/16/20 1:59 PM, David DiGiacomo wrote:
OP appears to be in Australia, so I doubt this is going to work.
I'm pretty sure Toby is in the US, even though his email is .au.

this may turn out to be a happy ending:-)

Re: What Tektronix means to me

 

Hi Jim,
The job offer letter from Tektronix is laminated on a plaque where it sits on my wall along side my diplomas. No. I never went to work at Tek. But in a way I got to become an honorary member of Tek.

I have been embraced by everyone I meet that is a current or ExTek employee. I have been included in their private mail reflector, I have been a member of the vintageTEK Museum since before it opened when Stan Griffiths first took me over to see the empty store front that would soon be its first home.

The biggest surprise was when Michael Dunn asked me to take over as moderator of TekScopes. Why me?

Usually 4 times a year I am in Beaverton visiting my Tek friends. Somehow one of the most famous design engineers at Tek heard about me several years ago and quite by accident I introduced myself to him at the museum. He replied "You're Dennis Tillman!" which stunned me. He is now one of my best friends. He is so highly regarded among ex-Tek employees that I will often call him to arrange a lunch with someone at Tek that was legendary. They never refuse. I have had many fascinating lunches with the people I might have known if I had become a Tek employee. We often met for lunch in the Tek cafeteria. Tek closed the cafeteria last month so I'm not sure where we will have those lunches next.

My favorite scope is the 7854. When I mentioned this to Deane Kidd at a swap meet one day he said the 7854 project manager was in the next room having a bite to eat and he introduced me to him. A few days later I asked him to autograph the cover of my 7854. He was puzzled why I would want his autograph.

Asking for autographs was something I had started to do when I was at Microsoft. For each Software Developer Conference I held I asked all the speakers to autograph their section of the conference notebooks. Bill Gates and Steve Ballmer's signatures are in them as are all the Windows developers and many of the famous software developers of the mid-1980s that attended the conferences.

By now that 7854 cover is so full of autographs of ex-Tek employees that I have had to switch to the other cover. When I'm all done with the covers I will give them to the 7854 Project Manager who is now a good friend of mine that I see every time I'm at a swap meet.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Jim Ford
Sent: Thursday, January 16, 2020 6:48 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] What Tektronix means to me

Hey, don't keep us in suspense, Dennis! Did you ever get to work for Tek?Jim Ford Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Dennis Tillman W7PF <@Dennis_Tillman_W7PF> Date: 1/15/20 10:36 PM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] What Tektronix means to me Hi Harvey,Yes, there is no simple solution to things being too far away but saying "I never expect to go there" (to the Tek Museum) is not the best way to start out if your goal is to get there. You never know what you ae capable of until you try. On more than one occasion I decided to hitch hike cross country from New Jersey to LA and up to San Francisco. Along the way I stopped at the St. Louis Gateway Arch, Grand Canyon, Mt Palomar to see the telescope, and the meteor crater in Arizona. On another trip down to the Keys I stopped at the new Disney World in Orlando. I've been to Mardi Gras three times.I had an offer to join Tek in 1968 when I was starting my junior year in college. But they recommended that I get my degree first and assured me that the job would still be there when I did. Life took me in a different direction by the time I got my BS E.E. degree. For the next 20 years I regretted that mistake. Instead I moved into a beach front apartment on the New Jersey shore and, to my surprise, I became a stained glass artist and beach comer and I went back to college, this time for a BA in Fine Arts. When I first heard it was possible to build a computer (a childhood dream of mine) I changed direction again and began building my own S-100 microcomputer. There were very few people doing that so I quickly found a job working on microcomputers. Eventually I became frustrated because I didn't understand software. That became my next challenge. Once I learned microcomputer programming I thought it would be smart to broaden my computer background with some mainframe experience. When I tried to do that I found out very few head hunters even knew what a microcomputer was. They were focused on filling the thousands of jobs available in the mainframe world. So I spent the next 6 months trying to get a mainframe job with no success. Eventually I was hired by an IBM 370 based time sharing company which saw there was an opportunity linking microcomputers to mainframes. That exposed me to IBM's premier operating system: Multiple Virtual Systems (MVS) and the many different IBM operating systems and applications that worked under MVS. Three years later someone recommended me for a job with Digital Research, the creator of CP/M (which I knew well), the industry standard 8-bit OS on microcomputers. Four years later that led to a job at Microsoft which I was desperate to get because it would finally bring me to the Pacific Northwest (Tektronix territory) where I would have been 20 years earlier if I had joined Tek. After 3 years at Microsoft it became clear I had the wrong background. They had their pick of graduating students with an MS in Computer Science or an MBA. So I went back to college a third time for an MS in Software Engineering. While I was getting that degree, Microsoft went from 500 people which was small enough that I knew almost everyone too many thousands of people. I don't like big companies and there were other opportunities for me now that I had an MS S.E.If you are on the other side of the earth and looking at a very small map it may appear that Microsoft (a few miles from Seattle), and Tektronix (a few miles from Portland) are right next to each other. It is a boring 3 1/2 hour trip to get there. Sphere Research is more than twice as far. On more than one occasion I decided to hitch hike cross country from New Jersey to LA and up to San Francisco. Along the way I stopped at the St. Louis Gateway Arch, Grand Canyon, Mt Palomar (to see the telescope), and the meteor crater in Arizona. On another trip down to the Keys and Key West I stopped at the new Disney World in Orlando. I've been to Mardi Gras three times. You shouldn't say things like I never expect to get there. It sounds like you really want to go. If you can make it to Seattle you have a place to stay with us. Portland is a train ride away. Beaverton is accesable by light rail from Portland. Dennis Tillman W7PF-----Original Message-----From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Harvey WhiteSent: Wednesday, January 15, 2020 5:28 PMTo: TekScopes@...: Re: [TekScopes] What Tektronix means to meI understand what you say, parallel to an extent, not congruent experiences.The Tek museum is 3000 miles from me, and I never expect to go there.Might we have something on the east coast?(and yes, I'm annoyed that Sphere's "free" days are even further fromme.) Still would like to find a 214 vertical amplifier board because mine has a bad channel A attenuator, not that I've asked before.)HarveyOn 1/15/2020 5:15 PM, Dennis Tillman W7PF wrote:> Like everyone here I have created a problem my wife will have to deal with when I am no longer around. She has the phone number of the vintageTEK Museum on our refrigerator. Problem solved.>> Now that that's out of the way I'm not concerned with recyclers and what will come of my stuff. I plan on enjoying the afterlife with a Tek 214 portable dual-trace storage scope in my coffin. The Egyptians had the right idea. Take what you can with you when you go.>> Tektronix gives me a reason to get up every day. I can explore anything in electronics with the instruments they designed. I am the beneficiary of the legacy of Tektronix; the standard of excellence they strove for; and the support they provided for their products.>> IN 1967 I bought my first Tek scope, a 453, new for $2,000. What I learned in the next two years by using that scope every night propelled me to the top of my class. That was the best investment I ever made. Tektronix instruments were investments in my future. 10 years later I bought a 7704A / 7A26 / 7B80 / 7B85 and a pair of P6106 probes for $7,000. I went into debt to do this because I knew it would pay off for me just like my 453 had. Two years later I bought a 7D01 / DF2 / DL2 for another $4,000 to study microcomputers. I eagerly learned microcomputer assembly language to control the microcomputer hardware I was designing. The next 10 years I had a very rewarding career in microcomputers, mainframes, operating systems, and software marketing.>> Several totally unexpected things happened starting in the late 1990s that were to enrich my life yet again. EBay gave me a way to buy all of the Tektronix instruments I could never afford back in the 1970s. In 2000 Michael Dunn started TekScopes and I joined 2 years later. Suddenly I was not alone. I had a vast resource of expertise to help me fix all the Tek instruments I was buying on eBay. 10 years ago Stan Griffiths and Ed Sinclair started the vintageTEK Museum as a showcase for all the things Tektronix had made possible. The museum is preserving the Tek legacy for the benefit of all of us. Last but not least we have our own specialized Wikipedia. TekWiki has become THE professional repository of Tektronix documents thanks to the tireless work of Kurt Rosenfeld. Working long hours alone, into the night, feeding every Tek document he can find into scanners. He has single-handedly assembled those papers, manuals, photographs, and comments into a beautiful, easy to use, library at our finger tips. TekWiki is every bit that is the rival of Wikipedia.>> I'm too busy using my collection of Tek instruments to dwell on what will happen to it someday. Because of Tektronix, eBay, TekScopes, the vintageTEK museum, and TekWiki my life is never dull when a Tektronix scope is within arm's reach.>> Dennis Tillman W7PF>>>-- Dennis Tillman W7PFTekScopes Moderator





--
Dennis Tillman W7PF
TekScopes Moderator

Re: 454 HV regulation off

Jack Ohme
 

Oh I already performed that test, Albert. 5 9 volt batteries plugged into
each other in series with my meter, diode checked it. Sure enough, worked
just fine.

On Thu, Jan 16, 2020 at 10:02 AM Albert Otten <aodiversen@...>
wrote:

Hi Jack,

For testing continuity between the CRT grid pin and the grid electrode a
rather safe method is to test grid-cathode as a diode. You have to remove
the socket to isolate the heater from the transformer winding. Supply 6.3 V
to the heater and supply DC between grid and cathode with a suitable series
resistor for current limiting (0.1 mA or so is enough). No other pins used.
Continuity will show up quickly. IIRC 25 V is enough.
This way you don't have to do measurements in the presence of HV.
I hope for you that you can exclude a CRT problem!

Albert



Re: Tek 604: Sad story, and CRT wanted

David DiGiacomo
 

On Thu, Jan 16, 2020 at 11:50 AM Tom Bowers <pvhengineering@...> wrote:
I have a new CRT for a 604, still in the original box, never used, it was
purchased as a spare that we never installed. How do I contact you off list
and where are you located.
Apparently you are not receiving the group messages in email. You
send a private reply by clicking on "View/Reply Online" in the
original message, then clicking the "Private" button. This seems to
be a real weak spot in the groups.io UI, since no one is able to
figure it out.

The CRT is in Colorado and I am not there right now, but could make
arrangements for you.
OP appears to be in Australia, so I doubt this is going to work.

OP, next time you go shopping for CRTs, you might at least want to
mention what continent you are on.

Re: Tek Scope Cart - Model 3 or K213?

Colin Herbert
 

I think you might find this more of a problem than you realise. The surface above the drawer at the bottom is covered in a textured soft plastic having an edging which also might be plastic, but may be metal. The curved triangular parts enclosing the pivot-points for the shelf assembly are plastic. Added to all of this, disassembly isn't a particularly simple task; even totally removing the drawer requires some ingenuity. I would leave it as it is, after a good clean-up and lubrication of the castoring wheels. It is a Tektronix product, after all, why would you want it to look like an IBM rip-off?
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of oakley@...
Sent: 16 January 2020 08:13
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tek Scope Cart - Model 3 or K213?

Thanks Colin, John, Harvey and Guy232 for your kind efforts to answer my questions.

I think that the Model 3 cart is clearly the winner over the K213 cart. The dimensional details and photos were very helpful in solidifying my decision.

Although it probably seems sacrilegious, I'm going to strip the Tektronix's blue and off-white vinyl finish and have the parts shot with textured Polane-T, matching IBM's traditional creme white and black finishes.

Thanks again!

Tom in SLC

Re: Tek 604: Sad story, and CRT wanted

Tom Bowers
 

Hello Toby,

I have a new CRT for a 604, still in the original box, never used, it was
purchased as a spare that we never installed. How do I contact you off list
and where are you located.
The CRT is in Colorado and I am not there right now, but could make
arrangements for you.

Tom Bowers

On Wed, Jan 15, 2020 at 10:31 PM <toby@...> wrote:

Hi group,

I bought a 604 XY from ebay late last year.

Have been checking the unit out, and while generally in good condition,
it's suffered some indignities, which appear to have destroyed the CRT.

Evidence of this was one corner of the tube faceplate chipped (without
destroying vacuum), ( https://imgur.com/a/aJQytLP ) the front CRT shroud
broken, and the blow was also enough to shatter the rear plastic
retaining clip, leaving the metal two-piece bracket and long screw loose
in the case.

However, the unit did power up to a ... spot. Actually two spots. The
upper spot is the real, controllable spot, while the brighter lower one
is apparently due to internal CRT damage:
https://imgur.com/a/SNQydLJ

So, I'm in the market for a replacement CRT. Potentially these:

154-0633-00 (p1)
154-0633-05 (p1)

But if 602 CRT's are compatible (??) then also:

154-0562-00 (p31)
154-0562-01 (p7) ****
154-0572-00 (p31)
154-0572-01 (p7) ****
154-0727-00 (p31)

154-0634-01 (p31) -- 603

I also have 602's and 603's so they'd be of interest anyway.

Thanks for any assistance

--Toby




Re: 454 HV regulation off

Albert Otten
 

Hi Jack,

For testing continuity between the CRT grid pin and the grid electrode a rather safe method is to test grid-cathode as a diode. You have to remove the socket to isolate the heater from the transformer winding. Supply 6.3 V to the heater and supply DC between grid and cathode with a suitable series resistor for current limiting (0.1 mA or so is enough). No other pins used. Continuity will show up quickly. IIRC 25 V is enough.
This way you don't have to do measurements in the presence of HV.
I hope for you that you can exclude a CRT problem!

Albert

Re: MEMBERS PLEASE READ: Our annual Group.io payment is due in 2 weeks.

Lawrance A. Schneider
 

Hello Mr. Tillman,

I have tried: Dennis Tillman W7PF
@Dennis–Tillman_W7PF
<@Dennis–Tillman_W7PF>
no caps
I can't remember there permutations I've tried a the moment, but each has failed to pass muster : Please enter a valid email address, name or mobile number (i.e. name@..., a name or 10 digit number only).

I would be more than happy to contribute!! What have I done wrong.
-----------
Further, I got this original missive this morning 16 Jan 20 .Why the delay??
I choose to get the group as conglomerate rather than individual missives.

Thank you Mr. Tillman for your efforts.

If you still need more money, I'll try snail mail.

Very gratefully, larry

Re: 2445 EPROMs

Chuck Harris
 

The processor in the 2445 is a 2MHz 6802 microprocessor.
It needs 250ns or faster memory.

Any 27128 you find is fast enough.

Why do you think you need to replace them?

-Chuck Harris

christopherbath@... wrote:

I need to replace the EPROMs in a 2445 oscilloscope. These appear to be two 27128 EPROMs with part numbers 160-1994-09 & 160-1995-09. Does anyone know the access time required for these? I am able to purchase 200ns access time 27128 but wanted to be sure these are sufficient. The existing EPROM part number is covered and I wanted to keep this intact in case I need to reuse these.

Thanks,

Chris



Re: Tektronix 532 LV rail shorted

randolphbeebe@...
 

Thanks Gentlemen, I will put it back on my bench and follow your suggestions. Also, I downloaded the "Circuit Concepts" Tekwiki publication and will read that as well as the 532 circuit description in the manual as John suggested. I am in the process of putting together an electrical work bench as a hobby and can navigate simpler circuits but the fact is I do not quite understand complex interrelationships of the 532 power supply.

The thing that caused me to suspect the rectifier tube sockets is that now there is no voltage reaching C640 at all. So I will check them as well.

Best,

Randy

Re: What Tektronix means to me

Chuck Harris
 

Having designed battery chargers for the US Army, I would
sure love to see your experimental data on rejuvinating lead
acid batteries.

I worked on that nut for a while, and determined that it was
impractical, as the lead sulfate conversion that occurs in
the lead plates during deep discharge did more than simply coat
and insulate the plates.

Lead sulfate is physically larger than the original mossy lead
in the battery plates, and when allowed to grow to excess, will
break up the mossy lead, and leave it to slough off the plates.
This sloughed off lead and lead sulfate usually ends up in the
bottom of the cell, or pierces the highly porous separators,
where it shorts the cell, ruining the battery.

Even if you could remove all of the accumulated lead sulfate,
the remaining mossy lead in the plates would have seriously
reduced surface area, and the cell's capacity would be a small
fraction of the original capacity.

So, if you have cracked that nut, I would sure like to see the
data.

-Chuck Harris

Ancel wrote:

For me...I became an Eng. in the late 80s when I discovered Tektronix 4 channel scopes (advert in Radio Electronics) which were equivalent of about 2 year's salary as a fresh graduate in the Caribbean.
They remained out of reach until many years later in 2012 when I acquired a 2465 and then a 2465/A as part of a Battery regeneration product development lab @ home.
They allowed me to develop and commercialize my first patent-able product.
http://www.mic.co.tt/page/green-tech-facility

I got the electronics bug. after seeing Star Wars in 1977 (as a 12 year old) and then buying a Radio Electronics mag. in a grocery check out aisle that offered an R2-D2 lookalike functional Robot project build.
This year I am launching the World's first electronic steel drum sticks (My countries national Instrument) https://en.wikipedia.org/wiki/Steelpan

Hope to have it on Amazon later this year. Was hoping to do manufacture in P. Rico...but things are a mess there right now.



Re: Thanks Tektronix

Jamie Ostrowski
 

I really enjoy hearing all of these stories. There's so much accumulated
knowledge and talent here it's just unbelievable!

Thanks for sharing the memories...

On Thu, Jan 16, 2020 at 9:29 AM Jim Ford <james.ford@...> wrote:

Rocket sled telemetry, eh? You didn't happen to work with a Mr. Murphy,
did you, Marvin? I understand that Murphy's law arose from a non-keyed
connector in the telemetry harness on a rocket sled. Or is that just a
myth?Jim Ford Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Marvin Moss <mmoss@...>
Date: 1/16/20 6:51 AM (GMT-08:00) To: TekScopes@groups.io Subject:
[TekScopes] Thanks Tektronix My thanks to Dennis for the fine job he is
doing. I started my Tek career as a student co-op at Radiation, Inc. in
Melbourne Florida in 1955. I worked in the test equipment dept for the
summer repairing the Tek stuff. I was always amazed at how you could clean
the Tek scopes by washing them with a hose outside in the parking lot and
then letting them dry with no damage to anything inside the scope. Also
Tek even provided silver solder inside the scope in case you did not have
any. I also became a Technician in 1956 (summer) and learned from the
master ( Bill Eddins) how to really use a Tek Scope. We were building a
new telemetry system for Col John Stapp's rocket sled out at Holloman AFB.
I learned a lot about design and testing that summer. I went on to the
University of Florida where I got a PhD in Electrical Engr in 1966 and a 32
year career at Lockheed. Tek has always been a part of my ham radio life
also and I now have 5 Tek scopes presently. Long live Tek!!