Date   
Re: 420A problem

 

can one today set up a gpib connection on a win 10 system and talk to this
thing ?
Depends on what you mean by "talk to".
If you mean just communicate with the scope, yes off course if you have a
working GPIB setup.
If you mean the adjustment software, no. It is a DOS application which won't
run on Win10 and also it requires an old ISA card NI GPIBII/IIA.

I don't think the adjustment would fix your problem anyway.

/HÃ¥kan

Re: 500 series plug-in pinout

 

I remembered seeing that page at Tekwiki but when I searched could not
find it.

On Mon, 23 Oct 2017 07:21:05 -0700, you wrote:

rfguy,

Kurt's Tek Wiki has a great article with everything you need

http://w140.com/tekwiki/wiki/500-series_plug-in_connector

Glydeck

Re: Electrolytic Cap Designations?

tom jobe
 

Thank you Chuck... for the capacitor lesson.
That's a fine document you put together!
As others have pointed out, we get to learn all sorts of good things on
Tekscopes.
tom jobe...

On 10/23/2017 7:10 AM, Chuck Harris cfharris@... [TekScopes] wrote:

Electrolytic capacitors have existed for somewhere around 100
years. Early varieties were wet, and used fairly caustic
liquid electrolytes. As time went on, the electrolytes were
made more and more gentle, up to today where they are essentially
non corrosive... to aluminum or its oxides.

Old fashioned electrolytic capacitors were essentially a blank
slate until they were "formed" by applying a low current DC
voltage to the capacitor. That "forming" built an oxide layer
that was adequate for the voltage applied. Over time, through
lack of use, the aggressive electrolyte would break down the
oxide layer, thinning it, and the voltage capability would
decrease, and the capacitance would increase.

Modern electrolytic capacitors have the oxide layer of the
electrodes preformed through a very carefully regulated
anodizing process. The manufacturer can create a layer of
oxide with very high precision, which predetermines the
voltage rating and the capacitance of a given plate area in
a capacitor. The electrolyte is highly conducting, but non
corrosive to the aluminum and oxide layers, which makes
reforming a useless activity.

Back in the old days, if you took a capacitor, and formed it
for say 10uf and 500V, the oxide was at its thickest after
the capacitor was formed, and consequently, the capacitance
was at its lowest value. As the capacitor aged, or was put
into use at a lower voltage, the oxide layer would thin, and
the capacitance would rise to a higher value.

New, it varied 0% from its design value, aged, it grew in
capacitance to as much as 100% of its design value.

So, you should start to see why the tolerance was written the
way it was.

Today, since the capacitor won't gobble up its oxide layer when
it sits on the shelf, or when used at a lower than maximum
voltage, there is little reason to use the old style tolerance
specification, and something along a +/-20% spec makes sense.

-Chuck Harris

Glenn Little WB4UIV glennmaillist@... [TekScopes] wrote:
Having tested and replace thousands of electrolytic capacitors, I have
found that recent manufacture aluminum electrolytic capacitors are
slightly below the marked value. The capacitance is well within the
stated tolerance. It is as if newer technology has allowed the
manufacturers of capacitors to optimize the amount of materials used to
get the most yield for the least material.

This is what I have found.
YMMV.

Glenn

On 10/23/2017 12:25 AM, David @DWH [TekScopes] wrote:

On Sun, 22 Oct 2017 23:02:26 -0400, you wrote:

I've always treated that as +100%, -0%

that it would be 100 UF makes no sense, because a cap could be 10 uf
to 110 uf, which is way too big a variance.

Thing here is that these caps are made to be bypass caps, where a
minimum value is important, and the maximum is less so.

Harvey
These days +/-20% is by far the most common. Mouser's search
facilities can be used to get an idea of how common the various
tolerances are for aluminum electrolytic capacitors:

-10%/+30% 652
-10%/+50% 1120
-10%/+75% 1361
-10%/+10% 400
-20%/+20% 49292

Usually the minimum value is the most important. Excessively large
values risk damage to the rectifier via large surge current however
this is moderated by transformer impedance and saturation so it should
never be a problem in a good design.



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

Re: DM5010 error 318

Harvey White
 

On Mon, 23 Oct 2017 14:32:17 -0700, you wrote:

Hi Harvey,
Please accept this as just one man's opinion. Form your own opinion based on
what you discover. But try to stop before you have wasted 6 months on a
hopeless cause like I did.
I've read the whole post, so I'll comment as things go on. I've
perhaps wasted a bit, but not a whole six months.

I managed to accumulate 3 of these at one time, all with various calibration
errors due to the internal batteries that maintain those calibration
constants running down.
Ditto here, I have three, all of which had bad batteries, although
I've replaced two of the batteries with lithium cells, diode in
series. (interesting conversation with person at batteries plus where
I tried to find a battery. Needless to say, I think I won....)



I will bet that none of the owners or users of these plugins ever saw the
line in the user manual that said the unit must be powered up every 6 months
to recharge those batteries. SO eventually the battery goes dead and with it
all hope of ever making it work again.
Oh, these things were decomissioned so long ago that this was a
guarantee. There is significant damage (at least to solder joints)
due to battery leakage. If I can't solve that well enough, then
they're going to be dead.


Because I had 3 of them with various constants that were zero'd out I
thought there was a good chance I could figure out how to put together one
or two good units. In addition I had the loan, from a friend, of a DM5010
that managed to still have all of its constants intact.
Oh, ok, well, not quite that lucky. I have three in various stages of
"good".



I knew the microprocessor instruction set of MPU inside the DM5010 and I had
a 7D02 logic analyzer and personality module for that MPU so, when all my
attempts to get the new constants to take hold failed (after replacing the
dead batteries of course) I started to disassemble the program it was
running.
Don't have that much, I've got a regular logic analyzer (16702B), and
I'm considering figuring how to download the right inverse assembler.
I've got several ways of doing that, but it's more work than I want to
do.

I'd like to redo the software in my 468's, but that is not as likely.
I do have a tracing disassembler that I wrote, will allow taking the
code apart all on a laptop. Bunch of work, though.



I have disassembled assembly language programs before a few times. They are
like jigsaw puzzles. At first you fit a few little pieces together then the
little pieces become larger and larger subsections of the whole thing. It is
a fun challenge and not that difficult once you understand how it should
work.
Done that myself. Could have been a better experience.



At the time I had the luxury of working on this for several hours a day in
between collecting unemployment, sending out resumes, and taking part in job
interviews. After 6 months of working on the DM5010 code I was getting
annoyed. I found where the constants were kept in memory fairly quickly but
I could not figure out what format they were in. They were all different and
some were short bits of memory (10 bits for example) and others were long
(24 bits for instance). I substituted various bit values into those
locations hoping to see how the software interpreted the result when I tried
to calibrate that setting but I could not spot the pattern.
Which tells me something, but go on....



A related mystery I never solved was how the constants were manipulated in
the software. Assembly language is easy to follow but the code I ran into
that manipulated the constants made no sense at all. I spent weeks
attempting to puzzle out what the code was going to do with the bits
representing a calibration constant. It made no sense. In the end my
conclusion was that the calibration constants and the algorithms that
processed them were written in a high level language such as Fortran 80 and
compiled into an op code module that became part of the software. Probing
deeper into that module would be pointless. I had no choice but to give up.
You know, that could be something that's quite possible. At that
rate, if I wanted these to work, (since I'm not working on
authenticity), I could go to plan "B".



Another thing about the DM5010: The measurement side is optically isolated
from the Readout and front panel controls. The measurement side converts the
reading to a bit string that is sent to the readout side to be interpreted.
It is bizarre to say the least but it has one huge advantage of true shock
isolation.
The HP 3456A does the same thing, multiple processors....



Finally one last thing. Tek tried many times to make a precision digital
Multimeter. The DM5010 was a failure for many reasons. For instance, it was
not all that accurate, and it couldn't measure current.
I know it doesn't measure current. I have a number of other DMM's
that do, along with 488 capability, and so on. So it's not like I
have nothing if I don't have this.

What were the other problems?

In the end Tek saw
the writing on the wall. They introduced a truly good precision DMM (it came
out after others had done the same thing). That was the DM5120. The irony is
they bought the module that is the guts of the DM5120 from Fluke (who did
know how to make a great DMM) and packaged it in a 3 wide Tek TM5000 plugin.
I've seen that in the catalogs, but never found one.

Well, then we have (on these three), damage due to leakage of the
batteries. I've got three (I suspect) good TMS9914 chips, a decent
timer/front panel interface chip, and the rest is problematic.

At this rate, I'd do better to figure out what the rest of the system
does to talk to this, and just redesign the whole CPU board with an
ARM processor, freeRTOS, a bunch of level converters, a 15 dollar CPU
board, and so on. Throwing in a CPLD might be a good idea. Now the
question is whether or not I *really* want to do that.

I think that I'll go clean the boards a bit better, see if that makes
a difference on one of them, and perhaps be able to get one out of the
whole mess. If I can't, then they go on the shelf for a bit more
until I decide if I want to mess with them again.

It's not a hard job to write the code, I'm pretty decent a C in this
kind of environment, so writing this would not be all that difficult
(done the display scanning and the like before, written graphics
drivers, etc...)

I like the board cleaning better, and I'll give that a try tomorrow.
Considering that most of the damage is in the vicinity of the CMOS
RAM, that might be the only problem with one of them.

Thanks for the opinion, I'll limit my involvement with this. It's not
like I have lots else to do.

Harvey


Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...]
Sent: Friday, October 20, 2017 7:30 PM
To: TekScopes@...
Subject: [TekScopes] DM5010 error 318

When calibrating a DM5010, I get error 318, bad ohms calibration constant.
This happens even when I am attempting to zero the reading.
It doesn't happen on some ranges, but does on others.

Not quite sure what to do about it. I have all the stuff needed to
calibrate it otherwise, I think.

I have three to work on, one with this problem, one that seems to want to
reboot and never make it out of power on test, and I'm not sure of the last
one.

The reboot one I can check the signatures, the one I'm not sure of I can
test further, but the 318 error? Not sure where that's coming from, is it
not storing the cal data properly (ram error?) or is it the ohms converter?

I've replaced the batteries in two of them with li batteries, diode in
series, very light drain. All three had some battery leakage and damage,
though.

Harvey



------------------------------------
Posted by: Harvey White <madyn@...>
------------------------------------


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

Yahoo Groups Links

Re: 1S1 upgrade kit available

snapdiode
 

Fair enough, I just wanted to tell people about a real Tektronix kit to upgrade, sorry, modify, their 1S1 with perhaps a more reliable part.

Anyways it's all moot now.

Re: DM5010 error 318

Ed Breya
 

I don't understand what's the big deal about the batteries running down on these. I don't have one, but I looked at the manual (because I couldn't believe anyone would design an instrument that couldn't recover from this), and quickly found the warning that if you disconnect the battery - to change it, for example - the cal constants are lost, so you have to do a re-cal according to the procedure in the manual.

Now, if the battery has leaked and damaged things, that's another story, but simply losing the cal constants shouldn't render it useless. I don't see why all the talk of undoing and rewriting code and such, if the manual explains how to restore it, step by step, using an internal jumper setting, along with common equipment that would be expected for DMM calibration.

Am I missing something?

Ed

FW: 154-XXXX-XX, 157-XXXX-XX, 290-XXXX-XX (Tubes and Nuvistors) For Sale

 

As I explained in the previous list of parts I posted on Oct 9 (see

Sent: Monday, October 09, 2017 1:23 PM
Subject: [TekScopes] 155-XXXX-XX (Custom ICs) For Sale



I have been asked by a non-member of TekScopes if we would be interested in
the Tek New Old Stock parts he has. I told him I would post his parts if he
would organize them by part number and decide on a price for each part. In
previous emails he has completed sorting out and pricing the Tek Custom ICs
and Selected or Matched Transistors. Now he has completed the Vacuum Tubes
he is selling.



Since he is not a member of TekScopes you should contact Steve Clark
directly at his email address ( <mailto:testequiplab@...>
testequiplab@... < <mailto:testequiplab@...>
mailto:testequiplab@...> ) to arrange a purchase.



I have no financial connection to this individual but since he is giving us
first choice and since the parts might otherwise have been sent to a land
fill I thought it was appropriate to let our members know what he has.



Dennis Tillman W7PF



Here is what Steve sent me today:



I finished the Vacuum Tube group. The prices were essentially matched to the
lowest of ebay, qservice or BC for similar new old stock (NOS). All items
are sold as NOS. Parts are guaranteed working fully to spec. All prices are
negotiable - especially if you want a quantity. I prefer not to get phone
calls. I will call any interested parties as needed.



Please contact Steve Clark at testequiplab@...
<mailto:testequiplab@...> <mailto:testequiplab@...> to place an
order or to ask questions.

PART NUMBER DESCRIPTION PRICE

154-0240-00 Sylvania 6110 10

154-0370-00 Amperex tube CZ1000 10

154-0417-00 RCA Nuvistor 8056 15

154-0432-00 Victoreen tube GV4S 5

154-0461-00 RCA NUVISTOR 8393 7

154-0461-00 RCA Nuvistor 8393 7

154-0465-00 RCA tube 7587 5

154-0465-00 RCA Nuvistor 7587 7

154-0491-00 Mullard Tube EL8608 10

154-0494-00 GE Compactron Tube 6GF5 10

154-0506-00 GE tube 16411 150

157-0003-00 RCA Tube 6AK5 Matched Pair 4

157-0020-00 GE Tube 6CB6 Matched Pair 5

157-0021-00 GE Tube 6CL6 Matched Pair 3

157-0038-00 GE Tube 12AU6 Matched Pair 4

157-0039-00 RCA Tube 6AW8 5

157-0051-00 RCA tube 5879 Matched Pair 8

157-0053-00 GE Tube 12BY7 Matched Pair 12

157-0059-00 GE Tube 6AU6 5

157-0063-00 GE Tube 6AK5 4

157-0075-00 RCA Tube 12AL5 Matched Pair 3

157-0082-00 GE Tube 6DK6 5

157-0099-00 RCA Nuvistor 8056 10

157-0100-00 Amperex Tube EC1000/8254 100

157-0103-00 RCA NUVISTOR 8393 10

157-0105-00 RCA Nuvistor 7586 Checked 7

157-0107-00 RCA Nuvistor 8393 7

157-0108-00 RCA Nuvistor 8393 10

157-0110-00 RCA Nuvistor 7586 7

157-0118-00 Amperex tube 12AT7 25

157-0121-00 RCA Nuvistor7586 Aged Matched Pair 7

157-0126-00 RCA Nuvistor 8393 Matched Pair 5

157-0127-00 RCA Nuvistor 8393 8

290-0493-00 GE Compactron 6M11 7

Re: Advice on replacing filter caps - 465B

Sudipta Ghose VU2UT
 

Hi Guys,
Very timely discussion (at least for me!). I am about to embark upon a
recapping project of my 465B.
By the way if any of the group member wants to have some adopter boards
etched, my PCB maker can do so very very cheaply even in small small
quantity.To keep the cost really low he needs 1:1 pdf files.
73
Sudipta Ghose VU2UT


On Mon, Oct 23, 2017 at 11:50 AM, Barry n4buq@... [TekScopes] <
TekScopes@...> wrote:



I think the adapter boards make the neatest repair. I've seen some
repairs
where the caps are just hanging out in the scope on wires, ech.

You only need single sided boards. They're simple enough that you could
use nail polish as a resist and etch your own. I used PnP blue and a
laser printer to make up some patterns. Use your favorite paint program
to make the images.

I use 105C snap caps where possible.

Paul
I've used PCBExpress and that works well for the layout. I'm trying to
avoid having to stock up on the chemicals needed to etch, etc.

Apparently dirtypcbs.com can use the Gerber files. If so, that seems to
be a good approach.

I'm not sure I can support another "hobby" (as in making PCBs...). :)

Thanks Paul,

Barry - N4BUQ



--
One of those ... ...

Re: DM5010 error 318

 

Hi Ed,
Sometimes the only way to truly understand something is to try it for
yourself. It would seem like it should be that easy. If you happen to find a
DM5010 and you have an evening to spare I would love to hear that you found
it easy to do. I met my match however.

In the meantime I thought taking another 30 minutes to write what I did was
a small price to pay to save someone else from going down a rat hole to
repair what is a rather underperforming instrument even on a good day.

Dennis Tillman W7PF

-----Original Message-----
Sent: Monday, October 23, 2017 6:48 PM
Subject: Re: [TekScopes] DM5010 error 318

I don't understand what's the big deal about the batteries running down on
these. I don't have one, but I looked at the manual (because I couldn't
believe anyone would design an instrument that couldn't recover from this),
and quickly found the warning that if you disconnect the battery - to change
it, for example - the cal constants are lost, so you have to do a re-cal
according to the procedure in the manual.

Now, if the battery has leaked and damaged things, that's another story, but
simply losing the cal constants shouldn't render it useless. I don't see why
all the talk of undoing and rewriting code and such, if the manual explains
how to restore it, step by step, using an internal jumper setting, along
with common equipment that would be expected for DMM calibration.

Am I missing something?

------------------------------------
Posted by: edbreya@...
------------------------------------

Re: DM5010 error 318

Ed Breya
 

Dennis, I still don't get it. The manual section 6 "Adjustment Procedure" says "The recommended interval for battery replacement is approximately every two years. Performance of the Adjustment Procedure is necessary after battery replacement to restore the calibration factors to memory."

This introduction is followed by about eight pages of step by step instructions on how to do it by changing a jumper inside, then doing the steps, then putting the jumper back to normal. I would think this is all that should be necessary, because it says so - unless the instrument has other problems.

It looks like the calibration generator has to be set to specific values, which the DM5010 expects at each step. Then it's confirmed, and the DMM figures out and stores the appropriate cal factors to make its measurement agree with the input. .

Ed

Re: DM5010 error 318

Dave Casey
 

Ed -

I think the problem is that Dennis and Harvey each believes he's done all
those steps correctly and not gotten the expected result, at which point it
is not obvious why. So perhaps the DM5010 isn't hard to calibrate and is
instead hard to troubleshoot when it won't calibrate.

Dave Casey

On Mon, Oct 23, 2017 at 9:29 PM, edbreya@... [TekScopes] <
TekScopes@...> wrote:



Dennis, I still don't get it. The manual section 6 "Adjustment Procedure"
says "The recommended interval for battery replacement is approximately
every two years. Performance of the Adjustment Procedure is necessary after
battery replacement to restore the calibration factors to memory."

This introduction is followed by about eight pages of step by step
instructions on how to do it by changing a jumper inside, then doing the
steps, then putting the jumper back to normal. I would think this is all
that should be necessary, because it says so - unless the instrument has
other problems.

It looks like the calibration generator has to be set to specific values,
which the DM5010 expects at each step. Then it's confirmed, and the DMM
figures out and stores the appropriate cal factors to make its measurement
agree with the input. .

Ed





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

Re: DM5010 error 318

Harvey White
 

On 24 Oct 2017 01:48:02 +0000, you wrote:

I don't understand what's the big deal about the batteries running down on these. I don't have one, but I looked at the manual (because I couldn't believe anyone would design an instrument that couldn't recover from this), and quickly found the warning that if you disconnect the battery - to change it, for example - the cal constants are lost, so you have to do a re-cal according to the procedure in the manual.
Exactly, requires voltages from 190 mv to 1000VDC, resistances 190
ohms to 19 megs, and AC voltages up to 700 VAC.


Now, if the battery has leaked and damaged things, that's another story, but simply losing the cal constants shouldn't render it useless. I don't see why all the talk of undoing and rewriting code and such, if the manual explains how to restore it, step by step, using an internal jumper setting, along with common equipment that would be expected for DMM calibration.
And it has, on each of the three I have, leaked and damaged things.
May be where the internal error (318) comes from.

Replaced batteries on two with Lithium batteries, diode in series to
prevent charging.

And you must recalibrate it.

typically, 190 volts is read as 196.54, so your readings will be off.



Am I missing something?
Just the damage being done and the internal errors and the need for
recalibration (who has 700 volts AC around?) I do, now....

Ditto variously for the resistance standards and the DC calibration
stuff. Problem though, is that while calibrating, and zeroing the
ohms function, I get error 318 (bad ohms calibration constant), which
more or less indicates a calibration RAM failure.

One has that, two don't boot....

If the rest of it works, then a more modern processor with a decent
NVRAM would take care of the whole silly thing. Of course, it's in
6802 assembly code (NOT 6502).

That's where the possible rewriting comes from... if I want to.

Harvey



Ed

Re: DM5010 error 318

Harvey White
 

On Mon, 23 Oct 2017 19:07:47 -0700, you wrote:

Hi Ed,
Sometimes the only way to truly understand something is to try it for
yourself. It would seem like it should be that easy. If you happen to find a
DM5010 and you have an evening to spare I would love to hear that you found
it easy to do. I met my match however.

In the meantime I thought taking another 30 minutes to write what I did was
a small price to pay to save someone else from going down a rat hole to
repair what is a rather underperforming instrument even on a good day.
Fixing these comes more in the "If I can get it working with not much
work." They've been sitting around for a while, though.

Harvey



Dennis Tillman W7PF


-----Original Message-----
Sent: Monday, October 23, 2017 6:48 PM
Subject: Re: [TekScopes] DM5010 error 318

I don't understand what's the big deal about the batteries running down on
these. I don't have one, but I looked at the manual (because I couldn't
believe anyone would design an instrument that couldn't recover from this),
and quickly found the warning that if you disconnect the battery - to change
it, for example - the cal constants are lost, so you have to do a re-cal
according to the procedure in the manual.

Now, if the battery has leaked and damaged things, that's another story, but
simply losing the cal constants shouldn't render it useless. I don't see why
all the talk of undoing and rewriting code and such, if the manual explains
how to restore it, step by step, using an internal jumper setting, along
with common equipment that would be expected for DMM calibration.

Am I missing something?

------------------------------------
Posted by: edbreya@...
------------------------------------

Re: DM5010 error 318

Harvey White
 

On 24 Oct 2017 02:29:36 +0000, you wrote:

Dennis, I still don't get it. The manual section 6 "Adjustment Procedure" says "The recommended interval for battery replacement is approximately every two years. Performance of the Adjustment Procedure is necessary after battery replacement to restore the calibration factors to memory."

This introduction is followed by about eight pages of step by step instructions on how to do it by changing a jumper inside, then doing the steps, then putting the jumper back to normal. I would think this is all that should be necessary, because it says so - unless the instrument has other problems.

It looks like the calibration generator has to be set to specific values, which the DM5010 expects at each step. Then it's confirmed, and the DMM figures out and stores the appropriate cal factors to make its measurement agree with the input. .
Yep, until you get internal errors (not really documented all that
well) during the process.

Ask, though, how many people have the equipment to do this, especially
the AC calibration stuff....

Harvey



Ed

Re: DM5010 error 318

Harvey White
 

On Mon, 23 Oct 2017 23:52:32 -0500, you wrote:

Ed -

I think the problem is that Dennis and Harvey each believes he's done all
those steps correctly and not gotten the expected result, at which point it
is not obvious why. So perhaps the DM5010 isn't hard to calibrate and is
instead hard to troubleshoot when it won't calibrate.
Error 318, internal error, bad ohms calibration constant. Anyone know
where in the 8K of assembly language code that comes from? I'm
suspecting the cause is a bad calibration constant RAM, or bad
connections to it.

If not, then the signature stuff (which does NOT check the calibration
RAM) is itself bad. (and it's not, other than one misprint).

Calibration, as you mention, is pretty straight forward, if it works.

Harvey



Dave Casey

On Mon, Oct 23, 2017 at 9:29 PM, edbreya@... [TekScopes] <
TekScopes@...> wrote:



Dennis, I still don't get it. The manual section 6 "Adjustment Procedure"
says "The recommended interval for battery replacement is approximately
every two years. Performance of the Adjustment Procedure is necessary after
battery replacement to restore the calibration factors to memory."

This introduction is followed by about eight pages of step by step
instructions on how to do it by changing a jumper inside, then doing the
steps, then putting the jumper back to normal. I would think this is all
that should be necessary, because it says so - unless the instrument has
other problems.

It looks like the calibration generator has to be set to specific values,
which the DM5010 expects at each step. Then it's confirmed, and the DMM
figures out and stores the appropriate cal factors to make its measurement
agree with the input. .

Ed





Re: DM5010 error 318

Dave Casey
 

Easier said than done, but I would figure out how the display is driven,
then find the code that contains the constant for displaying "318" and step
back from there.

How about swapping analog boards around from your other units to see if you
can find one that calibrates? Then you could look at the ohms circuitry
between the known good and known bad boards to identify the defect.

Dave Casey

On Tue, Oct 24, 2017 at 12:27 AM, Harvey White madyn@...
[TekScopes] <TekScopes@...> wrote:



On Mon, 23 Oct 2017 23:52:32 -0500, you wrote:

Ed -

I think the problem is that Dennis and Harvey each believes he's done all
those steps correctly and not gotten the expected result, at which point
it
is not obvious why. So perhaps the DM5010 isn't hard to calibrate and is
instead hard to troubleshoot when it won't calibrate.
Error 318, internal error, bad ohms calibration constant. Anyone know
where in the 8K of assembly language code that comes from? I'm
suspecting the cause is a bad calibration constant RAM, or bad
connections to it.

If not, then the signature stuff (which does NOT check the calibration
RAM) is itself bad. (and it's not, other than one misprint).

Calibration, as you mention, is pretty straight forward, if it works.

Harvey


Dave Casey

On Mon, Oct 23, 2017 at 9:29 PM, edbreya@... [TekScopes] <
TekScopes@...> wrote:



Dennis, I still don't get it. The manual section 6 "Adjustment
Procedure"
says "The recommended interval for battery replacement is approximately
every two years. Performance of the Adjustment Procedure is necessary
after
battery replacement to restore the calibration factors to memory."

This introduction is followed by about eight pages of step by step
instructions on how to do it by changing a jumper inside, then doing the
steps, then putting the jumper back to normal. I would think this is all
that should be necessary, because it says so - unless the instrument has
other problems.

It looks like the calibration generator has to be set to specific
values,
which the DM5010 expects at each step. Then it's confirmed, and the DMM
figures out and stores the appropriate cal factors to make its
measurement
agree with the input. .

Ed







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

Re: DM5010 error 318

 

I do as well as two 3458A DMMs in cal from Keysight.

If you are close to Forest Hill, Maryland, give me a shout.

I have done cals on the 5010. You need to be very careful to not miss a step.


Regards,
Tom

----- Original Message -----
From: Harvey White madyn@... [TekScopes]
To: TekScopes@...
Sent: Tuesday, October 24, 2017 1:24 AM
Subject: Re: [TekScopes] DM5010 error 318



On 24 Oct 2017 02:29:36 +0000, you wrote:

>Dennis, I still don't get it. The manual section 6 "Adjustment Procedure" says "The recommended interval for battery replacement is approximately every two years. Performance of the Adjustment Procedure is necessary after battery replacement to restore the calibration factors to memory."
>
>This introduction is followed by about eight pages of step by step instructions on how to do it by changing a jumper inside, then doing the steps, then putting the jumper back to normal. I would think this is all that should be necessary, because it says so - unless the instrument has other problems.
>
>It looks like the calibration generator has to be set to specific values, which the DM5010 expects at each step. Then it's confirmed, and the DMM figures out and stores the appropriate cal factors to make its measurement agree with the input. .

Yep, until you get internal errors (not really documented all that
well) during the process.

Ask, though, how many people have the equipment to do this, especially
the AC calibration stuff....

Harvey

>
>Ed
>
>

Re: Tektronix 533 Scope

Glydeck
 

Tom,

I used my 547 for real work today tracking down a simple D.C. Offset in an audio filter. Operation was bumpless.

David's list is spot on, and Kurt's Tek wiki is invaluable resource for these scopes.

Good luck, and keep us posted on your progress.

George

Sent from my iPad

On Oct 23, 2017, at 2:37 PM, David @DWH [TekScopes] <TekScopes@...> wrote:

I have a 545A and 547. I have not used them for real work in years
but they would still be useful if I did not have more modern
equipment.

In order I would:

1. Check the AC fuse.
2. Do a visual inspection inside the cabinet.
3. Power up the oscilloscope and check the power supply voltages.
4. Power up the oscilloscope and check that the high voltage inverter
is operating. This does not include checking the high CRT voltages
themselves since that will require a high voltage probe.

Tekwiki has a manual available:

<http://w140.com/tekwiki/wiki/533>

The 500 series can sometimes be a little tricky to get working so
reviewing the operating instructions may be necessary.

On 23 Oct 2017 18:49:50 +0000, you wrote:

My name is Tom Dodge, and this is my first post in here. One of my former coworkers gave me a Tektronix 533 Scope. I love Tektronix equipment by the way. Before i first powered it up, I plugged it into a Variac with a voltmeter so i could bring up the voltage to 115 volts. I switched it on, and noticed that I could not get a trace, and not even a beam with the beam finder. This is the first time I have tried to troubleshoot a scope. I know it probably has a high voltage problem. Where do I start with this? What kind of high voltage probe do I use for this? I have a couple of Tektronix probes that came with the scope and I have the manual. Where do I check first? Any suggestions would be appreciated. Thanks.

Re: DM5010 error 318

Ed Breya
 

OK, I think I get it now - the manual describes how it should work, when everything is right, but in practice, if anything at all isn't quite right, it doesn't like it and reports errors (or locks up?). The instrument needs very specific cal signals, delivered in a specific order, and no steps can be skipped without messing it all up. And, it won't tell you what it didn't like, or even work partially or inaccurately, which would at least help with diagnosing the problem. Is this approximately correct?

I have looked at the manual some more, and have some observations and suggestions.

1. I'm glad that I don't have one of these, and don't have to worry about it.

2. Presuming that the usual suspects like power supply issues are eliminated, I'd recommend that anything in sockets or that otherwise relies on mechanical contacts should be checked/rocked for the usual reasons. I think these products are well past the bad-TI socket and IC era, but if not, there's a very good suspect. The board edge connectors should also be worked over, just in case. Likewise, any front panel switches may be suspect, even though they operate in a digital realm. What if a bad pushbutton action isn't sufficiently debounced, causing excess entries that are not apparent?

3. If you want to write code, a good application may be to set something up to buzz or cycle K1631, perhaps a few hundred to a few thousand times. I'm guessing that it is not a hermetically sealed part, while all the other relays appear to be reed types. If it is a reed type, then disregard this suggestion. Even better would be to have some voltage across the contacts, current limited to a few mA, while the buzzing is on.

4. I trust that the firmware has not degraded over time, while a lot of other things have, making something just marginal enough to not work. So, redoing the uP and/or code seems like an exercise in futility for the sake of an old 4.5 digit DMM, which may readily let you down again, even if you get it working.

5. Needing a bunch of expensive cal equipment just to recover from a maybe five dollar battery failure seems not worthwhile, unless you have it anyway.

I don't think I have anything more to add to or subtract from the conversation, unless something occurs to me. It always does.

Good luck.

Ed

Re: 2465 Problem brightness intensity and readout intensity

David Az
 

From curiosity I made changed
Between a bords


FROM THE 2445
TO THE 2465
A4 OK


all the ic in A1 OK /

(Of course apart from IC U950)

A5 is the problem


When I moved the A5 board
2445
To
2465
Same problem as I bought it
The line is a point
And when I change the time
Slowly
the dot moves and stops in the middle of the screen
The ref DAC works pefect
1.247V
1.253V
Test points
1.36V
1.24V
What's annoying
The one that is perfectly calibrated
130%
100%
Cursors



Problem I have in 2465
That he is not calibrated
and the A5 from the 2445 is calibrated
So as far as the second scoop I bought the whole problem that is only a small glitch in board A5.
Ideas
will be welcomed

Let's save another tek scoop :)