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The code I used on TDS7104 was in the earlier message:
=======
tempBuf=malloc(0x800)
nvMem_read(0,tempBuf,0x800)
fdescriptor=open("dbfs:c:/vxBoot/eepromdump.bin",0x0202,0777)
bytesWritten=write(fdescriptor,tempBuf,0x800)
close(fdescriptor)
=======

I have tested the code on TDS7104. I didn't compare with an EEPROM programmer but extensively looked at the contents and I convinced myself it is correct.

The code you copied is from user Wevie for TDS8000 and it differs from TDS7104.
Ozan

Bonjour, we recieved a fine TEK 492 SA, circa 1980s..1990s, fine condition CAL in 2007. SN B055xxxx
Will post photo album.

Q: Do these have the notorius SMD lytics on some PCB that leak and corrode ?
Which PCBs are suseptible?

WTB: For nonprofit museum , restoration to original condition:
Original TEK front cover
small knob (intnesity, etc)
complete service manual (2 vol, binders) original printed version
MANY THANKS !!

Have an absolutely fantastic day!

Jon

Thank Benjamin for answering....
There is a 1000mfd/75wdc cap in the circuit, so there is a filtering (regulation) on this power supply, as I look with a scope at the waveform of the 32 v unreg, it is really 56 volts... in that case, the value of the cap should be much higher than 75volts... Well, I guess that I will have to dig on that !!
Best reguard's, By the way I usually speak french, so forgive my writing ...

When you look at the diagram, you observe that there is a regulation by the addition of a 1000 mfd/75wdc cap..and if it is really 56 volts, the value of the cap should be much higher..

Hi John:
Thank you for your kind offer.
I have a great 555 scope, which I intend to keep working.
I also have types CA, D, W, 1A7, and 1A5 plugins.
Would your parts stash include those from scavenged plugins?
In particular, my W plugin likely needs some part(s) for repair of the
large reference voltage selector rotary switch. Possibly a switch wafer,
although it has been a few years since I tried a repair.

Thanks for reading!

Randy
Tek 555, 7934, 7633, 7623, and HP, Fluke, and others.

On Mon, Jan 13, 2025 at 12:37?AM Nick Bergan via groups.io <nbergan13=
[email protected]> wrote:

Hi John,
Thanks for offering to share.
Do you have many 7000-series knobs and potentiometers?
I'm also looking for a correct graticule, light filter and CRT bezel for
my model 511 and model 422, which aren't exactly in the 500-series. If
nothing else, I might have to make my own or use parts from similar models.
I think I own or have seen just about all of the Tektronix analog scopes
in a 60-mile radius, lol.
I sure have made a lot of eBay purchases for how recent I got into the
restoration hobby. I'd hate to know how much I've paid in just shipping for
parts and tubes.

hers the scriptblock part i talk about:

tempBuf=malloc(0x20000)
acqLibReadNVRAM(0,tempBuf,0x20000)
fdescriptor=open("c:/eepromdump.bin",0x0202,0777)
bytesWritten=write(fdescriptor,tempBuf,0x20000)
close(fdescriptor)
‐----------------------------------------------------

This script block is a sequence of VxWorks commands designed to read data from non-volatile memory (NVRAM) and save it to a file. Here's a breakdown of each command:

tempBuf=malloc(0x20000)

Allocates a block of memory of size 0x20000 (131,072 bytes) and assigns the pointer to the tempBuf variable.
This memory is used to temporarily store the data read from NVRAM.
acqLibReadNVRAM(0, tempBuf, 0x20000)

Reads data from the NVRAM (Non-Volatile Random Access Memory).
The first parameter (0) likely represents the starting address or identifier for the NVRAM.
The second parameter (tempBuf) is the destination where the data will be stored.
The third parameter (0x20000) specifies the number of bytes to read.
fdescriptor=open("c:/eepromdump.bin", 0x0202, 0777)

Opens or creates a file named eepromdump.bin in the c:/ directory.
The second parameter (0x0202) is a bitmask specifying the file open mode. 0x0202 typically means "open for writing and reading, create if it doesn't exist".
The third parameter (0777) sets the file permissions to read, write, and execute for everyone.
bytesWritten=write(fdescriptor, tempBuf, 0x20000)

Writes 0x20000 bytes (131,072 bytes) from tempBuf into the file described by fdescriptor.
The result of the write operation is stored in the bytesWritten variable, indicating how many bytes were successfully written to the file.
close(fdescriptor)

Closes the file, ensuring that any pending data is written and resources are freed.
In summary, this script allocates memory, reads a block of data from NVRAM into that memory, and then writes the data to a file on disk named eepromdump.bin.

is this tested on the 7000 series also non- B ?
and compared to the eeprom content exported with a programmer. i can believe it is but i ask this because we worked on it for a longer time. and did not succeed completely

Hi i am Charlyd on the evvblog i thought i jump in here i guess i missed this perticular part, because i am a member in groups.io here..and very interrested in exporting the eeprom content on the 7000/7000B first of all keep up the good work in exploring your equiptment.

@ozan you say and that is correct as far as i know. the cal. const. are in the eeprom.

but the script extract it from the nvram how is that.... (sorry i send my reply in parts , because this is the third time i had to start retyping all here)

Hi John,
Thanks for offering to share.
Do you have many 7000-series knobs and potentiometers?
I'm also looking for a correct graticule, light filter and CRT bezel for my model 511 and model 422, which aren't exactly in the 500-series. If nothing else, I might have to make my own or use parts from similar models.
I think I own or have seen just about all of the Tektronix analog scopes in a 60-mile radius, lol.
I sure have made a lot of eBay purchases for how recent I got into the restoration hobby. I'd hate to know how much I've paid in just shipping for parts and tubes.

On Sun, Jan 12, 2025 at 04:18 PM, richard ramacieri wrote:

Hi.. I have a 465m with HV section blowing the fuse... Found that the 32v
unreg source voltage to be 56 volts !! ..A look at the diagram show the
transfo, then a bridge and a 1000 mfd cap rated at 75 vdc...Is it normal to
have 56 vdc instead of 32v unreg...I find this very unusual !! Please let me
know..

Schematic shows 52V typical with 116V supply voltage, 56V is not excessive especially if your mains voltage is a bit above 120V.
Ozan

Unregulated voltage is higher than what us really "says". For example, the +5V unreg on my scope is around +11V, which then gets regulated to +5V. According to my service manual this is normal

For your scope, the service manual doesn't give a voltage for that, so I would recommend you check the line input settings. If those are good the 56V is probably normal.

I would also recommend checking the regulation circuit for the +32V regulated as a short there can pop the fuse. Speaking of shorts, a shirt can by anywhere on the +32V rail, so you'll have to do some power tracing.

Another question, is it blowing F558 or F736?

If it's blowing F558, it's likely a problem with the HV transformer or the transistors/diodes that drive it.

Benjamin

Hi.. I have a 465m with HV section blowing the fuse... Found that the 32v unreg source voltage to be 56 volts !! ..A look at the diagram show the transfo, then a bridge and a 1000 mfd cap rated at 75 vdc...Is it normal to have 56 vdc instead of 32v unreg...I find this very unusual !! Please let me know..

Hi... My name is Richard, I recently acquired a 465m scope in mint condition..The problem is that the fuse in the high voltage PS burn instantly when the power is applied..Check all diodes, transistors, capacitor to be ok.. Didn't check the U555 so far... Voltage are ok, 5v and -5v and 32 volts, but as I went to check the 32 volts unreg use to supply the HV, I was surprise to see a reading of 56 volts.. As I look at the disgramm, this voltage come directly out of a bridge, filtered by a 1000mfd/75volts (wich voltage value is odd compare to 56 volts)..My question, is 56 volts normal at thispoint ?

Love to have it but is it in NZ? How much do you want for it?
PM: ccdman1 at outlook dot com
thanks

Hi all:
To add a bit to the surplus equipment discussion.
My employer (large aerospace company) had a surplus store for decades,
which had most everything from soup to nuts (almost literally). I was
fortunate enough to acquire much of my Tek, HP, Fluke, and other test
equipment from there for relatively reasonable, and sometimes fantastic
prices. Like my 7834 got it for $65, and it works(!). Most of the test gear
was either surplus to company needs, or had been replaced by something
newer. Back around 2000, as I was apprenticing to be an Analog ASIC
designer, the company purged a large number of electronics labs (“moving up
the proverbial “value chain” just another bean counter cost cutting move),
and huge amounts of test equipment would arrive for fairly good prices.

One of my visits found me looking at an HP 213 pulse generator (the tube
one with HV output), which an older couple had 2 of in their cart. Sadly, I
was not able to convince them to let go of one of them. To me, it seemed
they really did not know what they had, but oh well.

Sadly, that surplus store went away not too long after, likely on someone’s
hit list for cost reductions.
It is now an online entity, but not suited to mere mortals as myself, as
you need to buy in quantity ( a tub skid of wire cutters, let’s say), as
opposed to singly as in the old physical store.

Regards to everyone saving useful gear from wasteful landfills!!

Randy

Tek 555, 7834, 7633, 7623, HP, Fluke, Systron Donner, Analogic (Data
Precision 6200 Analyzer), ESI, Power Designs, Dynatech Nevada, and
miscellaneous.



On Mon, Nov 25, 2024 at 10:57?AM Clark Foley via groups.io <clarkfoley=
[email protected]> wrote:

It’s always interesting to see where the thread of a topic goes. This one
has been a lot of fun. In keeping with a “good home” theme, I remember a
designer at Tek who had a unique career objective. Amid one of our annual
layoffs, he told me that he was not distressed because his goal was to work
on projects in every department that produces instruments that he wants at
home. He was not a product-line zealot or afraid to switch jobs and he
didn’t want to ascend into a targeted position such as a manager. He knew
that each project produced “non-serviceable” prototypes that most likely
would go to a good home; his! When we last spoke, he said that he had
scopes and TM500/5000 stuff. Now he needed a spectrum analyzer; so, off he
went to Tek’s FDI (frequency domain instrument division).

Question to Jean Paul re: x-y distortion measurements method you mentioned.

I have an HP334 Distortion Analyzer, and in the HP manual, it tantalizingly
mentions a way to view distortion products. BUT there are no connection
details shown. I suspect it was left out in error.

I’d really appreciate any info anyone has related to the x-y measurement
technique with the HP 334 (or similar).
This has baffled me for years.

Thanks in advance,

Randy

Tek 555, 7834, 7633, 7623, 7D20, and a bunch of HP, Fluke, and other
instrumentation.


On Wed, Jan 1, 2025 at 6:28?PM Jean-Paul via groups.io <jonpaul=
[email protected]> wrote:

Probing the AE-35 unit in 2001 A space odyssey

Perhaps Tektronix P6006, Kubrick was a stickler for accuracy....



Jon

CLARK! YOU WONDERFUL HUMAN! YES, IT's the same power supply module.
Thanks a million!
And a million over!

Alex

Hi,

After long hours of measurements, cleaning etc. I had a final look at the acquisition board again and identified a suspiciuos via close to one of the infamous SMD caps ( see pic ).
I traced it and it turned out it was eaten up by the electrolyte.
After replacing the track with a wire the scope booted w/o errors and passed SPC.
What do we learn ?
Check all vias close to caps and pray they are not hidden underneath a part.
The broken connection carries the TRIGCC"B" signal between U1551 pin 26 and U624 pin 14.
One possible hint : SPC showed the following errors :

0x51efee4 (V main): TRIG"beta" trigGain[ CH1 ] 0.0 set to coldStart value
0x51efee4 (V main): TRIG"beta" dcOffset[ CH1 ] -1.6991698 set to coldStart value

Best regards
Hans

Hi Simon,

Thanks for the response.
After long hours of measurements, cleaning etc. I had a final look at the acquisition board again and identified a suspiciuos via close to one of the infamous SMD caps ( see pic ).
I traced it and it turned out it was eaten up by the electrolyte.
After replacing the track with a wire the scope booted w/o errors and passed SPC.
What do we learn ?
Check all vias close to caps and pray they are not hidden underneath a part.
The broken connection carries the TRIGCC"B" signal between U1551 pin 26 and U624 pin 14.
One possible hint : SPC showed the following errors :

0x51efee4 (V main): TRIG"beta" trigGain[ CH1 ] 0.0 set to coldStart value
0x51efee4 (V main): TRIG"beta" dcOffset[ CH1 ] -1.6991698 set to coldStart value

Maybe you should give it another try ?

Best regards
Hans

Hello,

some time ago I have acquired TDS744A in unknown condition. Whet it arrived it didn't turn on. I have checked main fuse and it was blown. I have dismantled the scope and found that power supply had catastrophic failure, specifically in section of standby power supply. Both NTCs exploded and created complete mess. I was checking what else was bad, BU508A power transistor had B-C short, CR10, CR11 diodes and VR1 zener shorted. I have cleaned all dirt and swapped blown components, including VR4 and VR5 TVS diodes and famous C17 capacitor. However power supply was still not working. Then I have been checking T3 transformer and found that it is unfortunately broken. It has inter-winding short on primary winding (using my Bob Parker ring tester).

I borrowed similar scope from my friend who was kind to allow me to temporarily desolder T3 transformer from his scope and use it in mine. After the swap my power supply started to work without any problem. This confirmed that really T3 is a culprit. I have also measured inductance, good transformer had 18mH on primary winding, bad one had just 1mH.

I would like to ask your help if anyone has power supply for parts and would be willing to desolder and send T3 transformer (I will cover all costs). It has label 22900937 REV M? (it is small 3x3x3cm cube). I have been checking pictures on internet and the same transformer was used in several different Tektronix TDS scope power supply models, not just in TDS744A.


Thank you very much.


Vladimir