Date   

Re: Ghost trace on Tektronix 2335

Andrija Ifkovic
 

I just checked and the internal calibration square wave is 931Hz / 220mV peak to peak. Oscilloscope is off as it measures about 190mV and 1040Hz. That is -14% off voltage and +12% frequency.

Beam finder doesn't really change the ghosting, it's still there and the ratio of the ghost trace is about the same as when beam finder is not on (+50% higher in both amplitude and frequency).


Re: I need Help: Eagle 7000 Scope Rear Interface ConnectorModel

Dave Daniel
 

John Griessen has artwork for 7000-series extenders. Perhaps he can help.

DaveD

On 10/1/2014 8:19 PM, 'Dennis Tillman' dennis@ridesoft.com [TekScopes]
wrote:

Rich,

The link you provided:
http://docmesure.free.fr/manuels/Tektronix/Serie%207000/0scillos%207000/7854
/7854/extender_card_project.htm seems to be a COPY of a web site
originally
created by Bob Ford.

There is a problem with the original Bob Ford web site: ALL of the
links are
broken. Anything that starts with www.bobford.plus.com is defunct. I
attempted to reach him at his email address (bobford@bobford.plus.com) but
that mail immediately bounced.

JAMMA boards are a 56 pin double sided standard on 0.156" centers. The pin
count is wrong and the spacing is wrong for 7000 series plugins which
use 76
pins (2x38) on 0.1" centers.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@yahoogroups.com [mailto:TekScopes@yahoogroups.com]
Sent: Wednesday, October 01, 2014 5:55 PM
To: TekScopes@yahoogroups.com
Subject: Re: [TekScopes] I need Help: Eagle 7000 Scope Rear Interface
ConnectorModel

Dennis,
You should be able to get some here:
http://docmesure.free.fr/manuels/Tektronix/Serie%207000/0scillos%207000/7854
/7854/extender_card_project.htm
The company below has parts that will allow you to make your own
cables or to buy the cables pre-made. I bought the PCBs that had holes
drilled in them. I just had to make up my own cables. I also bought the
female sockets when I purchased the cards. I made three cables. Here
is the
URL for them:
http://www.jammaboards.com/
It was a fun project and I believe that either one of these companies
can help you.
Thanks,
rich!

On 10/1/2014 7:24 PM, 'Dennis Tillman' dennis@ridesoft.com [TekScopes]
wrote:

Can anyone point me to an equivalent Eagle CadSoft model for the gold
fingers used on the end of a Tek 7000 series plugin?

This is a simple double sided design with 38 gold fingers on each side
spaced 0.1" apart. Fingers on 0.1" spacing are a pretty standard
arrangement used on a variety of products, from lots of companies.

I went through about half of the thousands of eagle connector diagrams
without spotting anything even close.

The free Eagle version limits you to 3.95" maximum which will just be
enough. The actual PC board used by Tek goes to 4.6" at its maximum
height but I think I can make the 3.95" Eagle limit work. It would at
least allow me to make some simple (inexpensive) extenders.

Thanks, Dennis Tillman W7PF




------------------------------------
Posted by: "Richard R. Pope" <mechanic_2@charter.net>
------------------------------------

------------------------------------

Yahoo Groups Links


Re: I need Help: Eagle 7000 Scope Rear Interface ConnectorModel

Richard R. Pope
 

Dennis,
Sorry about that!! I didn't know that about the first site. I would
send Jamma Boards an email and ask them about parts or cables for the
7000 series. Before I bought the parts to build my 500-5000 cables I had
a few questions and they were very helpful. They got back to me in one
business day.
Thanks,
rich!

On 10/1/2014 9:19 PM, 'Dennis Tillman' dennis@ridesoft.com [TekScopes]
wrote:

Rich,

The link you provided:
http://docmesure.free.fr/manuels/Tektronix/Serie%207000/0scillos%207000/7854
/7854/extender_card_project.htm seems to be a COPY of a web site
originally
created by Bob Ford.

There is a problem with the original Bob Ford web site: ALL of the
links are
broken. Anything that starts with www.bobford.plus.com is defunct. I
attempted to reach him at his email address (bobford@bobford.plus.com) but
that mail immediately bounced.

JAMMA boards are a 56 pin double sided standard on 0.156" centers. The pin
count is wrong and the spacing is wrong for 7000 series plugins which
use 76
pins (2x38) on 0.1" centers.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@yahoogroups.com [mailto:TekScopes@yahoogroups.com]
Sent: Wednesday, October 01, 2014 5:55 PM
To: TekScopes@yahoogroups.com
Subject: Re: [TekScopes] I need Help: Eagle 7000 Scope Rear Interface
ConnectorModel


Re: I need Help: Eagle 7000 Scope Rear Interface ConnectorModel

 

Rich,

The link you provided:
http://docmesure.free.fr/manuels/Tektronix/Serie%207000/0scillos%207000/7854
/7854/extender_card_project.htm seems to be a COPY of a web site originally
created by Bob Ford.

There is a problem with the original Bob Ford web site: ALL of the links are
broken. Anything that starts with www.bobford.plus.com is defunct. I
attempted to reach him at his email address (bobford@bobford.plus.com) but
that mail immediately bounced.

JAMMA boards are a 56 pin double sided standard on 0.156" centers. The pin
count is wrong and the spacing is wrong for 7000 series plugins which use 76
pins (2x38) on 0.1" centers.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@yahoogroups.com [mailto:TekScopes@yahoogroups.com]
Sent: Wednesday, October 01, 2014 5:55 PM
To: TekScopes@yahoogroups.com
Subject: Re: [TekScopes] I need Help: Eagle 7000 Scope Rear Interface
ConnectorModel

Dennis,
You should be able to get some here:
http://docmesure.free.fr/manuels/Tektronix/Serie%207000/0scillos%207000/7854
/7854/extender_card_project.htm
The company below has parts that will allow you to make your own
cables or to buy the cables pre-made. I bought the PCBs that had holes
drilled in them. I just had to make up my own cables. I also bought the
female sockets when I purchased the cards. I made three cables. Here is the
URL for them:
http://www.jammaboards.com/
It was a fun project and I believe that either one of these companies
can help you.
Thanks,
rich!

On 10/1/2014 7:24 PM, 'Dennis Tillman' dennis@ridesoft.com [TekScopes]
wrote:

Can anyone point me to an equivalent Eagle CadSoft model for the gold
fingers used on the end of a Tek 7000 series plugin?

This is a simple double sided design with 38 gold fingers on each side
spaced 0.1" apart. Fingers on 0.1" spacing are a pretty standard
arrangement used on a variety of products, from lots of companies.

I went through about half of the thousands of eagle connector diagrams
without spotting anything even close.

The free Eagle version limits you to 3.95" maximum which will just be
enough. The actual PC board used by Tek goes to 4.6" at its maximum
height but I think I can make the 3.95" Eagle limit work. It would at
least allow me to make some simple (inexpensive) extenders.

Thanks, Dennis Tillman W7PF








------------------------------------
Posted by: "Richard R. Pope" <mechanic_2@charter.net>
------------------------------------


------------------------------------

Yahoo Groups Links


Re: I need Help: Eagle 7000 Scope Rear Interface Connector Model

Richard R. Pope
 

Dennis,
You should be able to get some here:
http://docmesure.free.fr/manuels/Tektronix/Serie%207000/0scillos%207000/7854/7854/extender_card_project.htm
The company below has parts that will allow you to make your
own cables or to buy the cables pre-made. I bought the PCBs that had
holes drilled in them. I just had to make up my own cables. I also
bought the female sockets when I purchased the cards. I made three
cables. Here is the URL for them:
http://www.jammaboards.com/
It was a fun project and I believe that either one of these
companies can help you.
Thanks,
rich!

On 10/1/2014 7:24 PM, 'Dennis Tillman' dennis@ridesoft.com [TekScopes]
wrote:

Can anyone point me to an equivalent Eagle CadSoft model for the gold
fingers used on the end of a Tek 7000 series plugin?

This is a simple double sided design with 38 gold fingers on each side
spaced 0.1" apart. Fingers on 0.1" spacing are a pretty standard
arrangement
used on a variety of products, from lots of companies.

I went through about half of the thousands of eagle connector diagrams
without spotting anything even close.

The free Eagle version limits you to 3.95" maximum which will just be
enough. The actual PC board used by Tek goes to 4.6" at its maximum height
but I think I can make the 3.95" Eagle limit work. It would at least allow
me to make some simple (inexpensive) extenders.

Thanks, Dennis Tillman W7PF



I need Help: Eagle 7000 Scope Rear Interface Connector Model

 

Can anyone point me to an equivalent Eagle CadSoft model for the gold
fingers used on the end of a Tek 7000 series plugin?



This is a simple double sided design with 38 gold fingers on each side
spaced 0.1" apart. Fingers on 0.1" spacing are a pretty standard arrangement
used on a variety of products, from lots of companies.



I went through about half of the thousands of eagle connector diagrams
without spotting anything even close.



The free Eagle version limits you to 3.95" maximum which will just be
enough. The actual PC board used by Tek goes to 4.6" at its maximum height
but I think I can make the 3.95" Eagle limit work. It would at least allow
me to make some simple (inexpensive) extenders.



Thanks, Dennis Tillman W7PF


Re: Ghost trace on Tektronix 2335

 

I asked about the calibration because if both were off by the same amount, it
would indicated that the cathode voltage of -1960 volts is off which would cause
or indicate other problems as well.

You could always measure the voltage at the mesh pin. It should be about -150
volts.

On Wed, 1 Oct 2014 16:19:35 -0700, you wrote:

Thanks for suggestions. The trace shown is internal calibration signal which should be 1kHz 0.2Vpp. I will check whether issue is present even on beam finder when I get home. Vertical calibration is fine and I think horizontal is as well (didn't check that one recently). I used it for many years in this state. I can try looking at polystyrene capacitor that was previously suggested as well.


Re: Ghost trace on Tektronix 2335

Andrija Ifkovic
 

Thanks for suggestions. The trace shown is internal calibration signal which should be 1kHz 0.2Vpp. I will check whether issue is present even on beam finder when I get home. Vertical calibration is fine and I think horizontal is as well (didn't check that one recently). I used it for many years in this state. I can try looking at polystyrene capacitor that was previously suggested as well.


Re: Ghost trace on Tektronix 2335

 

I do not think there is any doubt that it is coming from the scan expansion
mesh.

What signal is shown in your photo? Is it the 1 kHz calibrator signal? Is the
horizontal and vertical calibration good?

x10 magnification lowers the effective beam intensity to 1/10th so it is
expected that it would ameliorate the problem.

I was not able to duplicate the severity shown in your photo on a 2232 nor 2247A
before or after a warm up period. I suspect the problem will be worse on CRTs
which have low operating hours.

The 2335 and 2336 are suppose to be ruggedized and I assume that includes the
CRTs. Maybe this is a characteristic of them at high brightness.

one person replaced diodes and capacitors in the switching PS (voltage quadrupler) to get rid of a similar looking problem but on a completely different non-Tek scope
Ripple in the CRT cathode or anode voltage will cause the entire display to
become blurred including any traces. It would not cause a ghost trace without
affecting the normal trace.

On Wed, 1 Oct 2014 14:41:22 -0700, you wrote:

No other suggestions? Googling didn't produce much more information other than it may be related to high voltage stability - one person replaced diodes and capacitors in the switching PS (voltage quadrupler) to get rid of a similar looking problem but on a completely different non-Tek scope. On 2335 those are all under a metal shield and not even marked on schematics (they show diodes but not what they are and there is no part id either).


Re: Ghost trace on Tektronix 2335

Mike <Patriot121@...>
 

Is it all ways there .. even with beam finder ?
intensity?


On 10/01/2014 02:41 PM, Andrija Ifkovic aifkovic@yahoo.com [TekScopes]
wrote:

No other suggestions? Googling didn't produce much more information
other than it may be related to high voltage stability - one person
replaced diodes and capacitors in the switching PS (voltage
quadrupler) to get rid of a similar looking problem but on a
completely different non-Tek scope. On 2335 those are all under a
metal shield and not even marked on schematics (they show diodes but
not what they are and there is no part id either).



--
Mike KC7NOA


Re: Ghost trace on Tektronix 2335

David DiGiacomo
 

On Sat, Sep 27, 2014 at 5:12 PM, Andrija Ifkovic <aifkovic@yahoo.com> wrote:
So I replaced the Zener, it was a nerve-wracking experience and a hack job. Unfortunately it did not help, after 10+ minutes of beautiful screen the ghosting came back. The only thing I noticed is that if I push out the 10X magnifier button on the scope (so that it's disengadged), then the ghosting is far less visible at any brightness and you can probably say it looks fine. Maybe that gives a clue as to what's going on?
Are you saying you only see the ghosting with the magnifier on? If
so, I don't think there is anything wrong with your scope, that's just
how the scan expansion CRT works.


Re: Ghost trace on Tektronix 2335

Andrija Ifkovic
 

No other suggestions? Googling didn't produce much more information other than it may be related to high voltage stability - one person replaced diodes and capacitors in the switching PS (voltage quadrupler) to get rid of a similar looking problem but on a completely different non-Tek scope. On 2335 those are all under a metal shield and not even marked on schematics (they show diodes but not what they are and there is no part id either).


Tek 576 for $250 BIN pickup in San Diego

 

Pickup or freight only in San Diego. Needs repair.
Ebay 390943192224

No affiliation.

Jay


Re: SPS6919 replacement

Bob Koller <testtech@...>
 

It is a 151-0341-00 or 2N3565.

On Tuesday, September 30, 2014 11:54 AM, "maxxim_66@yahoo.com [TekScopes]" <TekScopes@yahoogroups.com> wrote:




Who can tell me about this transistor , in my 2465 found open Q1376, A2 board , equivalent to?
nothing found by google.



[Non-text portions of this message have been removed]




[Non-text portions of this message have been removed]


Re: Homebrew scope

Bert Haskins
 

On 10/1/2014 5:35 AM, Mark Wendt mark.wendt.ctr@nrl.navy.mil [TekScopes] wrote:
On 09/30/2014 09:11 PM, Manfred Mornhinweg manfred@ludens.cl [TekScopes]
wrote:
Dear all,

what did you do before you got your first Tek scope? How did you get by in life?
How could you even survive?
I've built several, two from scratch, and some that were almost totally reworked heathkits.
Things are much easier if you start with a low deflection voltage CRT like a 3WP1.

Most of the "cheepy" scopes got their high voltage from a winding on the power transformer
and this is just so bad on so many levels.
I had some very good "dumb" luck in adapting flybacks from small TVs for this purpose.

My first real scope was a Raytheon (Cosser) 50MHZ portable which is still working well today.
My first good Tek, I don't put 2213/15(s) in that spot, was a 465M which I now have too many of.
As a side to Mark Wendt, did you work with any "M"s in the AF?

Like many others on this list I'm now trying to "thin the herd".

Bert


File - Posting Rules

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Regards,
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Listowner, TekScopes


Re: Homebrew scope

Mark Wendt <mark.wendt.ctr@...>
 

On 09/30/2014 09:11 PM, Manfred Mornhinweg manfred@ludens.cl [TekScopes] wrote:
Dear all,

what did you do before you got your first Tek scope? How did you get by in life?
How could you even survive?

If you want to read about one of the sins of my long gone youth, have a look at
this page, which I completed and uploaded just minutes ago!

http://ludens.cl/Electron/scope/scope.html

Manfred
Manfred,

I'm in awe. That's just pure genius! Well done!

I never had a scope of my own till a few years ago. When I was a kid, like your poor, undeserving student, I had no money to speak of. My neighbor down the road got me interested in electronics (he was a ham) and also model airplanes. He had a Heathkit scope on his bench that he'd made. We eventually built (as a buddy project) a model airplane radio control transmitter and receiver. Had a lot of fun doing that, and he was a heck of a good teacher. After graduating from high school, and piddling around in college for a few years not really sure of the direction I wanted to take in life, I ended up enlisting in the USAF, and becoming an avionics communications and navigation tech, working on everything from tube receivers to solid state stuff, and eventually on data-link and IR/TV guidance systems. I eventually finished up my degree while still in the USAF, got my commission as a 2nd Lieutenant, went to flight school, got my wings and flew F-4's for the rest of my career in Uncle Sam's Great Fraternal Flying Club. Fast forward a few years, got hooked up with another old retired electronics nut through our hobby of machining stuff, and he pointed me to all the Tek scopes and "stuff" on Ebay. First Ebay purchase was a 7623. Then a TM504. Then plugins to calibrate. Then other plugins like the SC series of scopes. Then a 7603 with a Spectrum Analyzer. Then a 7854. Then some HP equipment.

Oy. What have I gotten myself into?

Mark


Re: Homebrew scope

David Thomas
 

.. brings back some memories of my first scope, which I built aged 14 in
the 70's......

I had picked up a scope chassis, tube and mains transformer at a radio
rally - a friend of mine found a circuit diagram of a Heathkit 2 valve
scope, which I copied as far as I could - I developed about 600V for the
CRT using a voltage doubler off the 300V winding - the "PCB" was an old
IF strip from a Murphy TV - I removed the original components, leaving
just the ceramic PCB mount valveholders and rebuilt using the existing
holes and tracks (cut & link where necessary!) - the components were
mainly stripped from old TVs (including the valves) - my first "scope
probe" was a length of thin coax stripped from a TV, terminated in a
wire point and encased in an old BIC biro tube!

That scope went a long way towards my understanding of oscilloscope use,
and general electronics, so I suppose it was worth every penny of what I
didnt spend on it....(!)

Wish I had a photo of that one now!

This was eventually replaced by an ex-army (valve) scope from another
radio rally, which was then replaced by a more modern unit - but both
the valve scopes went to good friends to help them further their
electronics hobbies.... so maybe they are still out there somewhere?

Best Regards

David Thomas


On 01/10/2014 02:42, 'Phil Sittner' sittners@sbcglobal.net [TekScopes]
wrote:

Manfred-

What an impressive project. The old adage "necessity is the mother of
invention" and it is certainly true in your case. I'm thrilled to have
seen it.

Phil
kd6rm
----- Original Message -----
From: Manfred Mornhinweg manfred@ludens.cl [TekScopes]
To: TekScopes@yahoogroups.com
Sent: Tuesday, September 30, 2014 6:11 PM
Subject: [TekScopes] Homebrew scope

Dear all,

what did you do before you got your first Tek scope? How did you get
by in life?
How could you even survive?

If you want to read about one of the sins of my long gone youth, have
a look at
this page, which I completed and uploaded just minutes ago!

http://ludens.cl/Electron/scope/scope.html

Manfred

========================
Visit my hobby homepage!
http://ludens.cl
========================




Re: Homebrew scope

Paul Read
 

Hi Manfred and gang

What a fantastic write up, many thanks for taking the time to share it with us.
It brings back memories of the PW (Practical Wireless magazine) Student that I built while at school in the '70s, it had a bandwidth of a few 100kHz and never did work very well, even though my dad took it into his lab at work to let the techs there have a go at it. The tube in that was a 3BP1 and as I recall I was able to make a lot of the chassis during metalwork class !
I keep seeing that copy of PW turning up on Ebay.
During my first job my bench scope was a little Hameg 207 and during my second job, I was given a Tek 465 :o)) and this was with me until fairly recently when I was able to swap it for a 2245A. A t this point I realy caught TAS (Tek acquisition syndrome) and have a growing selection.
Thanks again for the great write up.

Cheers

Paul


Re: DM501 constant blinking display

Jerry
 

Ok, I now know more about a DM501 than I ever thought I would. It started
with a bad latch, progressed to blown power supply transistors, and
wrapped-up with a blown floating supply as well. I then proceeded to pop a
couple of 7474's and one or two 7400s. At that point all I had to fix was
a blinking display. I then popped the power supply again as well as
floating power. After getting the floating supply back up, giving up twice
and buying two more in the process, I was finally able to get a display of
all zeros that wasn't blinking.



The next 16 hours or so found me tracking down a 2n3904 the repairman
soldered into the tightest spot on the board instead of a 3094. I'll tell
you, the guy fixing this thing (me) is an idiot.



Once that transistor was replaced with the correct type I am back to a solid
display with one bug - the OL function isn't working. You might remember
that at one point I had nothing but OL. The irony of the situation makes me
want to pitch the stupid $9 voltmeter down the hill.



How hard can the OL function be to fix? Who the hell needs OL anyway!



The interesting thing is this DMM listed for $495 in 1973, 42 years ago. At
3.7% compounded that is $2,277 in todays money. It is basically a TTL
analog to digital converter with some decent components in it.So now I can
put three dual tracking supplies with meters in this frame pretty cheaply,
maybe a total of $200 invested.



Thanks to all those that sent me pointers and for reading this far.



Jerry



_____

From: TekScopes@yahoogroups.com [mailto:TekScopes@yahoogroups.com]
Sent: Sunday, September 28, 2014 5:14 PM
To: TekScopes@yahoogroups.com
Subject: Re: [TekScopes] DM501 constant blinking display





On 28 Sep 2014 13:07:25 -0700, you wrote:

I hooked it to my voltage and meter standard and it displayed perfectly. I
then went to extract the probes and it pulled from the frame and your's
truly pushed it back in. So I spent about 5 hours trouble shooting until I
find a blow transistor, replaced it, and powered on.

Doh!

It now displays perfectly but the screen blinks constantly. I checked all
the voltages and they are in spec. It's like it has a stuck bit or
something. I would say the blink rate is about 1/2 second.

I searched the manual and the only time it should blink is when it is OL,
no?

That is the way I understand it. It should blink if the number of counts is
greater than 19,999. The theory section on page 2-5 points to U325B as being
in
the circuit path for controlling the blinking. I assume that the level at
pin 3
of U330 is going low.

82561 - 82580 of 192975