Date   

TDS8000 / CSA8000 ACQ Calibration Failed

dalek
 

Anyone had any success getting the calibration procedure to work on these? I purchased six of these units, they all had the normal things wrong (NVRam batteries, corrupt bios). Have go to the point where they all work but once they load the application they show ACQ recall failures, same on each one. Looking on the net other people have seen these but I am yet to find a remedy. Looking at the serial header on the PowerPC board I see after vxWorks loads:
0x2abb500 (aCalDiagExecutor): CCMgr: Recall ACQ cal constants failed!
0x2abb500 (aCalDiagExecutor): --> Initializing to defaults!
0x2abb500 (aCalDiagExecutor): CCMgr: Recall user ACQ comp data failed!
0x2abb500 (aCalDiagExecutor): --> Initializing to defaults!
The GPIB interface works, commands I have sent to try and make the machine happy and not report errors include:
syst:prot off
cal:save:fact:mai
cal:updateinfo:mai
syst:prot on

syst:prot off
comp:sav:fact:all
cal:save:fact:mai
cal:update:all
syst:prot on

:syst:prot off
:cal:save:fact:mai
:cal:updateinfo:mai
:syst:prot on

:syst:prot off
:comp:sav:fact:all
:cal:save:fact:mai
:cal:update:all
:syst:prot on

eevblog mentions in depth information on the 7404 which is similar but not fully helpful. I have tried the toggle switch on the PowerPC board in both positions with the above commands.


Re: TM506

Stephen
 


Re: TM506

Stephen
 

On Sat, Jul 25, 2020 at 02:42 PM, Harvey White wrote:

Interleaved

I think someone gave you a direct link.  You may have to more or less
match with more modern components.
Yes. I posted before seeing Michael’s post with the link to the list.
I found what I needed. All these are 2N2905A and 2N2219A pairs.

I’m gonna change the pair that was directly connected to the 33R resistor that was charred.
It’s very difficult to probe anything with a scope in that area without an extender.

One thing I can tell you tight of the bat, is that when my scope is DC
coupled,
And the trace is on the center horizontal line, when I plug in the FG502,
The trace goes directly off screen to the bottom. Even if the FG has the
Offset off (pushed).
This is not the case when the scope is AC coupled.
That means I have Neg DC bleeding through when I shouldn’t have any. I
either have to move the trace back
up on the scope, OR use the DC offset switch to inject Positive DC to bring
it back up. But that crushes the signal to the point where it almost a
straight line.

Can be one of two things, or perhaps a combination.

1) negative driver turning on too much

2) positive driver not turning on enough

what I *think*, because the + part of the trace is distorted, is that
the + driver chain is not driving the output properly.

what the circuit does is

1) take a single ended input (from the amplitude pot)

2) convert it to a differential (+ going and - going) signal

3) amplify it, running it through a bipolar amplifier, which is capable
of both + and - excursions.  This is an alternate approach to a push
pull output.  the "upper" transistors take care of the + excursions, the
"lower" transistors take care of the - excursions.  In a push pull tube
amplifier, there's generally a driver transformer, or a circuit that
splits the input.  That is applied to two output tubes fed out of phase,
and the audio output transformer puts those phases back together, since
the amplifier is likely a class B or there abouts.

In transistors, there exist transistors that can run off - voltages, so
you typically have an output stage where one transistor (the + one)
pulls the output +, then is turned off where the - transistor pulls the
output -      tubes can't do this well, but it's possible.  (Tektronix
did it in their vertical and horizontal scope amplifiers).

So you're dealing with a similar design, but no transformers means DC
response possibilities, so really, no LF limit unlike transformer
coupled designs.

Since transistors can drive low impedance loads directly, no output
transformer is needed.
All of this makes perfect sense. Thank you Harvey.


Re: TDS540B switches during boot VGA output from color to monochrome

unclebanjoman
 

Hi Henry,
I've just sent a PM to you!
Cordially,
Max


Re: Dead TM500 plug-in sought

Colin Herbert
 

I have a couple of the Dan Meeks extenders, which are rather more useful. They have better module and mainframe connections and have test-points, jumpers and tell-tale leds for 25VAC "A" and "B", 11.5VDC, and 17.5VAC and +/-26VDC. They use a ribbon-cable for the interconnection and are a work of art. However, if you want to check whether the pass-transistors are working or not, you still have the fiddly problem of making connections to two sides of the female connector at the same location. My idea is to bring out a number of the back-plane connectors to a front panel so that they are easily accessed for checking. I think Tek made a module that would do something like this, but I have never seen one (067-1201-99 ?).
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of DaveH52
Sent: 25 July 2020 19:52
To: TekScopes@groups.io
Subject: Re: [TekScopes] Dead TM500 plug-in sought

I bought one of these to act as an extender:
https://www.amazon.com/gp/product/B00F1YQMXO/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1
and it works perfectly without an modification other than cutting a slot in the male end to accommodate the connector keys in the chassis.


Re: Ferrite Beads in Tek Transistor Adapters

Daveolla
 

At 09:11 AM 7/25/2020, you wrote:


This is why we have "Warning" labels on Preparation H that states "not to be taken orally".

--
Michael Lynch
Dardanelle, AR
You can take your Preparation H and shove it where the sun doesn't shine!

Dave


Re: Is it OK to talk Keithley here since it's part of Tek?

Brian Cockburn
 

Roy,

Did you mean Test-Equipment-For-Sale-Wanted-or-Exchange@groups.io? If so then that's not really a forum to talk and ask questions about Keithley kit. Or did you mean some other group?

Cheers, Brian.


Re: Dead TM500 plug-in sought

Harvey White
 

Thanks, already took a morning and went past that point.  All pin breakouts, LM7805 regulator and included 3.3 volt regulator if needed.  Idea was not to make extenders (although this could be the start of one), but a plugin/supply board I can use to power a project in a TM500 frame.  Most of my designs use a 5 volt bulk supply, which may power the I2C off board interface, and on board 3.3 volt regulators that power everything else.

Something might come of this,  for example, the module slot tester that Tektronix made, but I don't need the +5 and +/- 15 volt supplies.  Do need lots of binding posts, though.

Harvey

On 7/25/2020 11:05 PM, John Griessen wrote:
On 7/25/20 8:44 PM, Harvey White wrote:
If I did a board for the TM500 series (or TM5000), I'd be designing the board myself,
There is pcb-rnd editable data and rs274-x fabbable data for this available free by asking me:
https://www.ecosensory.com/tek/tek_tm_flex_pcb_bot.jpg
https://www.ecosensory.com/tek/tek_tm_flex_pcb_top.jpg

and it fits in TM500s TM5006's fine.



Re: Dead TM500 plug-in sought

John Griessen
 

On 7/25/20 8:44 PM, Harvey White wrote:
If I did a board for the TM500 series (or TM5000), I'd be designing the board myself,
There is pcb-rnd editable data and rs274-x fabbable data for this available free by asking me:
https://www.ecosensory.com/tek/tek_tm_flex_pcb_bot.jpg
https://www.ecosensory.com/tek/tek_tm_flex_pcb_top.jpg

and it fits in TM500s TM5006's fine.


Re: TM506

J Mcvein
 

-----Original Message-----
From: "Stephen" <stephen.nabet@...>
Sent: Saturday, July 25, 2020 8:44pm
To: TekScopes@groups.io
Subject: Re: [TekScopes] TM506



On Sat, Jul 25, 2020 at 12:49 PM, Michael W. Lynch wrote:


On Sat, Jul 25, 2020 at 06:03 PM, Harvey White wrote:


Tek WIKI has, or should have, a list of transistors and their equivalents,
if
any. I'd check there if any transistor seems bad when measured. However.
TekWiki has several resources.

This PDF is a very good source for Cross reference specs:

http://w140.com/tek_xref_free.pdf

There reference section that contains many other resources.

Go to TekWiki and search for reference materials.

Good luck,

--
Michael Lynch
Dardanelle, AR
Thanks Michael. I couldn’t find it.


Re: Dead TM500 plug-in sought

Harvey White
 

Ouch, didn't realize that.  If I did a board for the TM500 series (or TM5000), I'd be designing the board myself, and not using JAMMA adaptors.

Thanks.

Harvey

On 7/25/2020 7:54 PM, Vince Vielhaber wrote:
Just be careful of the upper pins on the JAMA extenders.  Some have the a number of the A and B tied together.  I didn't notice it and toasted a plugin.

Vince.

On 07/25/2020 05:37 PM, scm@... wrote:
If you search on eBay (Search terms: jamma harness,56). you will find many priced $12.00, or so and up, including shipping.



Re: TM506

Harvey White
 

interleaved as usual, next post is next post...


On 7/25/2020 8:32 PM, Stephen wrote:
On Sat, Jul 25, 2020 at 12:03 PM, Harvey White wrote:

Interleaved:

Tek WIKI has, or should have, a list of transistors and their
equivalents, if any.
If there is a list like that, I couldn’t find it.
I think someone gave you a direct link.  You may have to more or less match with more modern components.

Turn the amplitude down to zero.  turn off the output offset. Look at
the output.  Whatever output you get should by symmetric around zero,
use a scope set on DC coupling.  pull out the offset and run it from +
to -.  The output ought to go equally from + voltage to - voltage.  Push
in the output offset

Look at the signal at the top of the amplitude pot, it should be
undistorted.

Increase the output level until the output is distorted, but not on both
+ and -.  Follow the output from the arm of the amplitude pot (DC offset
turned off) through the output amplifier looking at the signals on the
collectors of the transistors.  Whichever one shows distorted is the
source of the problem.
One thing I can tell you tight of the bat, is that when my scope is DC coupled,
And the trace is on the center horizontal line, when I plug in the FG502,
The trace goes directly off screen to the bottom. Even if the FG has the Offset off (pushed).
This is not the case when the scope is AC coupled.
That means I have Neg DC bleeding through when I shouldn’t have any. I either have to move the trace back
up on the scope, OR use the DC offset switch to inject Positive DC to bring it back up. But that crushes the signal to the point where it almost a straight line.
Can be one of two things, or perhaps a combination.

1) negative driver turning on too much

2) positive driver not turning on enough

what I *think*, because the + part of the trace is distorted, is that the + driver chain is not driving the output properly.

what the circuit does is

1) take a single ended input (from the amplitude pot)

2) convert it to a differential (+ going and - going) signal

3) amplify it, running it through a bipolar amplifier, which is capable of both + and - excursions.  This is an alternate approach to a push pull output.  the "upper" transistors take care of the + excursions, the "lower" transistors take care of the - excursions.  In a push pull tube amplifier, there's generally a driver transformer, or a circuit that splits the input.  That is applied to two output tubes fed out of phase, and the audio output transformer puts those phases back together, since the amplifier is likely a class B or there abouts.

In transistors, there exist transistors that can run off - voltages, so you typically have an output stage where one transistor (the + one) pulls the output +, then is turned off where the - transistor pulls the output -      tubes can't do this well, but it's possible.  (Tektronix did it in their vertical and horizontal scope amplifiers).

So you're dealing with a similar design, but no transformers means DC response possibilities, so really, no LF limit unlike transformer coupled designs.

Since transistors can drive low impedance loads directly, no output transformer is needed.

Harvey



If the board is charred to the point where the resin binder in the
fiberglass is carbonized, the board will be bad.
It’s not that bad. However, all the transistors we talked about on the output amplifier, get extremely hot.
I mean The heat sinks are literally burning hot.
BTW, What I meant by “noisy” earlier in the previous posts, is actually A pretty well defined and steady oscillation.



Re: TM506

Stephen
 

On Sat, Jul 25, 2020 at 12:49 PM, Michael W. Lynch wrote:


On Sat, Jul 25, 2020 at 06:03 PM, Harvey White wrote:


Tek WIKI has, or should have, a list of transistors and their equivalents,
if
any.  I'd check there if any transistor seems bad when measured.  However.
TekWiki has several resources.

This PDF is a very good source for Cross reference specs:

http://w140.com/tek_xref_free.pdf

There reference section that contains many other resources.

Go to TekWiki and search for reference materials.

Good luck,

--
Michael Lynch
Dardanelle, AR
Thanks Michael. I couldn’t find it.


Re: TM506

Stephen
 

On Sat, Jul 25, 2020 at 12:03 PM, Harvey White wrote:

Interleaved:

Tek WIKI has, or should have, a list of transistors and their
equivalents, if any.
If there is a list like that, I couldn’t find it.

Turn the amplitude down to zero.  turn off the output offset. Look at
the output.  Whatever output you get should by symmetric around zero,
use a scope set on DC coupling.  pull out the offset and run it from +
to -.  The output ought to go equally from + voltage to - voltage.  Push
in the output offset

Look at the signal at the top of the amplitude pot, it should be
undistorted.

Increase the output level until the output is distorted, but not on both
+ and -.  Follow the output from the arm of the amplitude pot (DC offset
turned off) through the output amplifier looking at the signals on the
collectors of the transistors.  Whichever one shows distorted is the
source of the problem.
One thing I can tell you tight of the bat, is that when my scope is DC coupled,
And the trace is on the center horizontal line, when I plug in the FG502,
The trace goes directly off screen to the bottom. Even if the FG has the Offset off (pushed).
This is not the case when the scope is AC coupled.
That means I have Neg DC bleeding through when I shouldn’t have any. I either have to move the trace back
up on the scope, OR use the DC offset switch to inject Positive DC to bring it back up. But that crushes the signal to the point where it almost a straight line.

If the board is charred to the point where the resin binder in the
fiberglass is carbonized, the board will be bad.
It’s not that bad. However, all the transistors we talked about on the output amplifier, get extremely hot.
I mean The heat sinks are literally burning hot.
BTW, What I meant by “noisy” earlier in the previous posts, is actually A pretty well defined and steady oscillation.


Re: Dead TM500 plug-in sought

Vince Vielhaber
 

Just be careful of the upper pins on the JAMA extenders. Some have the a number of the A and B tied together. I didn't notice it and toasted a plugin.

Vince.

On 07/25/2020 05:37 PM, scm@... wrote:
If you search on eBay (Search terms: jamma harness,56). you will find many priced $12.00, or so and up, including shipping.


Re: TM506

Michael W. Lynch
 

On Sat, Jul 25, 2020 at 06:03 PM, Harvey White wrote:


Tek WIKI has, or should have, a list of transistors and their equivalents, if
any.  I'd check there if any transistor seems bad when measured.  However.
TekWiki has several resources.

This PDF is a very good source for Cross reference specs:

http://w140.com/tek_xref_free.pdf

There reference section that contains many other resources.

Go to TekWiki and search for reference materials.

Good luck,

--
Michael Lynch
Dardanelle, AR


Re: Dead TM500 plug-in sought

Harvey White
 

Some JAMMA harnesses have pin 7 missing.  This will prove a problem when the harness is inserted with pin 1 connected to pin 1.  In the TM500 series, from pin 14 on are not dedicated lines, and are used only to connect one plugin to another on the back panel.  Reversing the harness will place the missing pin in this group and you should be able to use the JAMMA harness for power connections.

Harvey

On 7/25/2020 5:37 PM, scm@... wrote:
If you search on eBay (Search terms: jamma harness,56). you will find many priced $12.00, or so and up, including shipping.



Re: TM506

Harvey White
 

Interleaved:

On 7/25/2020 5:58 PM, Stephen wrote:
On Sat, Jul 25, 2020 at 10:19 AM, Harvey White wrote:

I had a similar problem on another unit, might have been one of the FG
series.  The pullup transistor for the output was bad.
The problem is that all the transistors for the output are unknown (to me at least). Besides 1 or 2 2N3607A’s, they all have just a tektronix parts number In the manual, like 151-xxxx-xx, or S0xxxxx. Even if one was bad, I can’t replace it without knowing what it is.

Tek WIKI has, or should have, a list of transistors and their equivalents, if any.  I'd check there if any transistor seems bad when measured.  However.

Check the no-signal output voltages, you should be able to achieve a DC
offset of zero volts with no output.  Increasing the output while
watching it on a scope should start to show distortion at higher
amplitudes (guessing that insufficient + excursion is in the amplifier.
I don’t know how to do that.
Turn the amplitude down to zero.  turn off the output offset. Look at the output.  Whatever output you get should by symmetric around zero, use a scope set on DC coupling.  pull out the offset and run it from + to -.  The output ought to go equally from + voltage to - voltage.  Push in the output offset

Look at the signal at the top of the amplitude pot, it should be undistorted.

Increase the output level until the output is distorted, but not on both + and -.  Follow the output from the arm of the amplitude pot (DC offset turned off) through the output amplifier looking at the signals on the collectors of the transistors.  Whichever one shows distorted is the source of the problem.



Many of the boards will discolor over time in the presence of heat.
This is more or less normal, but ugly.  discolored board with charred
part, that isn't.
Indeed.
If the board is charred to the point where the resin binder in the fiberglass is carbonized, the board will be bad.

Harvey



On 7/25/2020 3:30 PM, Stephen wrote:
Ok, now that the TM506 is up and running perfectly again (thanks to all of
you who guided me), now I have 3 plugins to fix: FG502, DC503, and SC502.
Starting with the FG502. I took a closer look at it today. Visual
inspection. R532 was charred. I replaced it, as well as C532. All the other
resistors in that cluster read the correct 33 ohm value. A large area in that
zone seems to have been exposed to a lot of heat. The bord is discolored.
However, all the traces are present and good. I did redo some solder joints
though. But I still have the same problem. As long as I don’t go up past
(10 -2), all is kind of ok if I don’t push the voltage past 9 o’clock.
The square waves are far from being sharp, but at least they look like square
waves. Past 9 o’clock it gets extremely noisy and distorted, and the
waveforms don’t look the way they should. Starting at (10 -3) everything is
ugly and completely off. Sines look like triangles, and square waves pretty
much the same, no matter what the voltage is set at.
Since everything is base on the triangle wave... Should I start by looking
at that first? Or is the voltage output messing everything up? Regulator
problem maybe?
BTW, I’ve of course checked all the voltages, and they’re dead on: +20,
-19.9, 17.1, -17.1



Re: TM506

Stephen
 

On Sat, Jul 25, 2020 at 10:19 AM, Harvey White wrote:


I had a similar problem on another unit, might have been one of the FG
series.  The pullup transistor for the output was bad.
The problem is that all the transistors for the output are unknown (to me at least). Besides 1 or 2 2N3607A’s, they all have just a tektronix parts number In the manual, like 151-xxxx-xx, or S0xxxxx. Even if one was bad, I can’t replace it without knowing what it is.

Check the no-signal output voltages, you should be able to achieve a DC
offset of zero volts with no output.  Increasing the output while
watching it on a scope should start to show distortion at higher
amplitudes (guessing that insufficient + excursion is in the amplifier.
I don’t know how to do that.

Many of the boards will discolor over time in the presence of heat. 
This is more or less normal, but ugly.  discolored board with charred
part, that isn't.
Indeed.

On 7/25/2020 3:30 PM, Stephen wrote:
Ok, now that the TM506 is up and running perfectly again (thanks to all of
you who guided me), now I have 3 plugins to fix: FG502, DC503, and SC502.
Starting with the FG502. I took a closer look at it today. Visual
inspection. R532 was charred. I replaced it, as well as C532. All the other
resistors in that cluster read the correct 33 ohm value. A large area in that
zone seems to have been exposed to a lot of heat. The bord is discolored.
However, all the traces are present and good. I did redo some solder joints
though. But I still have the same problem. As long as I don’t go up past
(10 -2), all is kind of ok if I don’t push the voltage past 9 o’clock.
The square waves are far from being sharp, but at least they look like square
waves. Past 9 o’clock it gets extremely noisy and distorted, and the
waveforms don’t look the way they should. Starting at (10 -3) everything is
ugly and completely off. Sines look like triangles, and square waves pretty
much the same, no matter what the voltage is set at.
Since everything is base on the triangle wave... Should I start by looking
at that first? Or is the voltage output messing everything up? Regulator
problem maybe?
BTW, I’ve of course checked all the voltages, and they’re dead on: +20,
-19.9, 17.1, -17.1




Re: Dead TM500 plug-in sought

SCMenasian
 

If you search on eBay (Search terms: jamma harness,56). you will find many priced $12.00, or so and up, including shipping.