Test Equipment Anonymous (TEA) group therapy thread

[factory]

Happy new year and nice to see Duracell providing the fireworks in New Zealand. 

[]https://www.youtube.com/watch?v=41D2267fjtA[]



David

[tautech]

I was nowhere close by ! 

[factory]

This afternoon I built up a vero board with the 74HCT390 counter stage & attached it to the latch/multiplexer board and fitted HCT version of the 74LS74 & 74LS14, I now have a more healthy +5.1V on the supply rail  , but seem to have created another problem, need to check if it's a wiring error on my part, or maybe a dead IC, or a dead digit readout bulb (might not be as the decimal point still lights). 

Well it wasn't a wiring error or dead numerical indicator bulb, turned out to be related to swapping out the LS TTL ICs for lower power CMOS HCT versions. The 74HCT74 didn't have enough oomph to drive both the two multiplex ICs and the P, Q outputs. One of the P, Q lines was stuck at zero volts, now back working with the 74LS74.
I did actually read about this a few days ago in a Philips databook on the Nexperia webpage, HCT can only drive a few gates, regular TTL can drive more.



Just got one more problem to figure out now, the BCD counters switch the carry output at 1000 counts, but I need to figure out how to get it to display 0000 at this point, as at present I have sensible readings on volts & ohms if you minus 1000 from the displayed result, I kind of thought this would happen.





Might have a play with a 74HC4040, eight input NAND gate and an analog switch in the count line tomorrow.

David

[m k]

I refresh my definitive opinion.
A bit bigger than needed proto board is better than a bit smaller than needed proto board.

The board is also less double sided than one may think, better leave one hole row/column for side change.

Low left of front are data lines to Arduino, not needed for copying and pulled away from disturbing.
D6-D7 can be used for checking readyness of write sequence, but long enough wait will eliminate that need.

Original Arduino connection wires were colored multicore ribbons with sort of male pin headers, but after a day of use and troubleshoot some were already almost cut.
The board had also a nasty feature where one chip was differently copied than the other and both were ok when tried with MiniPRO.

Address is coded as 2x6 with D8-D13 and 2xLS374, 13th is Arduino A5.
All Arduino analog pins are digital out and others than A5 are for selecting things.

Since address is multiplexed its troubleshooting is pretty easy, all lines have double meaning.
Also since LS374 has rising edge as data input those selection lines can be reused for later things, here for EEPROM _W and _E.

The whole analog pin thing goes so that
01234
00111 start
10111 low address and A12 in, LS374/1 pin 11 rising edge
11111 high address in, LS374/2 pin 11 rising edge
11110 address out, both LS374 pin 1
11100 27C64 read, _CE and _OE
01000 28C64 write address, _W and _E
11000 28C64 write data, rising edge of _W
11010 disable 27C64
10010 28C64 data read, I skipped this and used 4ms wait instead
10111 disable address and 28C64
00111 next round

Arduino A5 is ready for A13 if needed and other LS374 has a ready spot for it.

A14 and A15 are also possible, their content can be put to Arduino A3 and LS374 pair has still last data slot free.
It's also a good practice to pull Arduino A3 up before latching address out.

Since D0-7 are still completely unused they can be used for reading data to Arduino if needed.
For writing EEPROM also of course.

One idea for the PCB was where one ROM is on the other side of the board, then half of wiring is much easier.
But for simple counter solution using 2x4bit 74393 is not saving chips since carry is missing.
3x74174 seem to be the smallest foot print for addresses.
But then actual counter part is still missing, easiest is probably dual 555 for read and write waits.

[factory]

Last update on the Advance DMM2 for this week, back to boring & noisy work tomorrow.

Took me a while to get to the component drawers containing the 74HC4040 & analog switches, I got a surprize as there was two 74HCT4040 in the HC draw  , had to make do with a DG412DJ for the analog switch, had some others with higher supply voltage requirements (DG419 would have been preferred), found a 74LS30 for the NAND.



Now got it working with the separate counter stage for the carry output, the 8 input NAND is set to toggle the analog switch, to the display counter at 999 counts, this might need some minor adjustment as it has a 2 in the LSD with input shorted, the zero adjustment will not lower it. Voltage display is now much better, but I can't get the full count of 1999, will try the 200mV range next weekend with a mV source.



As I don't have a paper manual to work from (hate using PDFs on the phone), it was at this point I noticed it stated the PSU should be adjusted first, before the zero. The PSU is regulated on the primary side at +9.5V, I'm not really sure how close the secondary voltages should be to the stated +17V, -12V & +5V. With the primary set at +9.5V, the +5V rail is at +5.6V, maybe could use more LS TTL to lower it, depending on what is still made in surface mount package.

The voltages when I first started were;
TP5 (+190V) = +180V
TP6 (+5V) = +5.2V
TP7 (-12V) = -11.8V
TP8 (+17V) = +16.4V
With +9V on C39 (primary)

To be continued....

David

[Vince]

Micropross ROM 3000U vintage EPROM programmer


NEW EPISODE just been released  !  ---- > > >

https://www.eevblog.com/forum/repair/vintage-chip-programmer-micropross-rom-3000u/msg4617247/#msg4617247

Today we played with the non-standard boot disk that came with the programmer, made an image of it using ImageDisk and then looked at its contents using HxC , revealing cool stuff inside...

[TERRA Operative]

I pulled the old Fluke 332D DC Voltage Standard back out onto the bench, time to get it working.

https://www.eevblog.com/forum/repair/fluke-332d-restoration/msg4615084/#msg4615084

[m k]

The PSU is regulated on the primary side at +9.5V, I'm not really sure how close the secondary voltages should be to the stated +17V, -12V & +5V.

These electric document times a big screen is pretty much a must.

+17V is clearly quite important.
Both zeroings are straight between +17V and -12V.
I guess until ICs shutdown or burn it's adjustable.

[xrunner]

Trying a new DSO for a change. It's an SDS2202X-E.

Well ... at least that's what the label on the box sez. 

[tautech]

Trying a new DSO for a change. It's an SDS2202X-E.

Well ... at least that's what the label on the box sez. 

Cool, it arrived. 
Just check it has this latest firmware installed:
https://int.siglent.com/upload_file/zip/firmware/Oscilloscope/SDS2000X-E_V1.1.20R3_EN.zip

[xrunner]

Trying a new DSO for a change. It's an SDS2202X-E.

Well ... at least that's what the label on the box sez. 

Cool, it arrived. 
Just check it has this latest firmware installed:
https://int.siglent.com/upload_file/zip/firmware/Oscilloscope/SDS2000X-E_V1.1.20R3_EN.zip

Yea will do. I'll unbox it after my cat-nap. If it's damaged I don't want to know about it 'till after that. 

[tautech]

Trying a new DSO for a change. It's an SDS2202X-E.

Well ... at least that's what the label on the box sez. 

Cool, it arrived. 
Just check it has this latest firmware installed:
https://int.siglent.com/upload_file/zip/firmware/Oscilloscope/SDS2000X-E_V1.1.20R3_EN.zip

Yea will do. I'll unbox it after my cat-nap. If it's damaged I don't want to know about it 'till after that. 

Really, do your delivery people like to play football with parcels ? 
Of the 100's we dispatch each year none are ever damaged.

BTW, give those 2 probes a darn good working over and claim warranty on any duds, even if 'not quite right'.
They should be rock solid and be immune to any little wiggles of the coax but it seems some are getting through QC from Siglent's supplier and as it's not the first it's happened I've been screaming at them to use another supplier and give the current monkeys the push. 
Official reply; we're working with our supplier to identify issues...... FFS without decent probes throw the scope away.

[xrunner]

Geez - just when I get a new toy we get a 2 hour power outage in the 'hood.

OK so I got it powered on and it looks good. Easy to operate the basics and I like the user interface. Let me get into it more tomorrow.

[tautech]

 
Now put the little coloured rings on the probes will ya ! 

[duckduck]

Had a package from Digi-Key waiting for me when I got back from Xmas vacation. I replaced the noisy old fan in my HP 8656A Signal Generator with a noisy new fan. The ground line to the fan uses a M4x8 screw (not included) instead of an #8-32, but otherwise is a straight drop-in replacement. I couldn't find the datasheet for the 40-year-old OEM fan so I just picked the closest thing that was 120 VAC, cast-metal frame, and ball bearing. I used the Orion Fans OA92AP-11-2TB:

https://www.digikey.com/en/products/detail/orion-fans/OA92AP-11-2TB/2621009

https://orionfans.com/oa92ap-series/

I'm finally able to test my Wilson frequency counter up to the full 500 MHz. It actually works up to 710 MHz. The HP and the Wilson even agree within 500 Hz (you can see additional digits on the Wilson if you push in the "KHz" button). Are they both within their respective specifications? I don't know, but it is a good omen.

EDIT:

Time to play TE Tetris again to get all of my latest TE onto the lab shelving.

[xrunner]

Now put the little coloured rings on the probes will ya ! 

Oops ... looks like that issue with the probe coax is happening with one of them. Do I send an email to info@siglentna.com ?

[tautech]

Now put the little coloured rings on the probes will ya ! 

Oops ... looks like that issue with the probe coax is happening with one of them. Do I send an email to info@siglentna.com ?

Yep and get a screenshot of it fucking up the trace if you can. Blue Print button to a USB stick. 
Sorry mate as you might need 3 hands to properly capture it.

Give them 1x/10x switches a good workout too but get V/Div low so to keep the waveform on the display at either setting. Just do one probe at a time or it gets too busy for those you send it to.

[xrunner]

Yep and get a screenshot of it fucking up the trace if you can. Blue Print button to a USB stick. 
Give them 1x/10x switches a good workout too but get V/Div low so to keep the waveform on the display at either setting. Just do one probe at a time or it gets too busy for those you send it to.

OK, no biggie at the moment. It's pretty easy to use without looking at the documentation. So far I haven't had to. I really like the selectable input impedance right there, built-in. The firmware was already the most current version. Did self-tests and self-cal. Looking at pulses from my vintage Tek PG501 pulse gen. I'll do a bandwidth check and more tomorrow. Looks like a winner for my personal needs. 

[tautech]

Even with the dicky coax termination into the probe they are still quite usable providing you don't even breathe on them and this is where they just get accepted as normal for a Chinese probe.
NO, they can do better than that and what's to say this dicky coax termination doesn't get worse with time and suddenly you're up for a $40 replacement !

I get pretty anal about this stuff and one I reported recently got a reply from the VP of engineering at HQ.
They really need to sort this shit ! 

[xrunner]

Email sent to Siglent N.A. with pic regarding bad probe.

Using Tek PG501 pulse gen, to compare the new SDS2202X-E with the Old Girl DS1054Z. She's been opened up to 100 MHz but I measured the BW to be ~130 MHz. 50 ohm termination attached to input of DS1054Z.

Both results combined into one pic with measurements displayed.

[med6753]

While I don't participate in this thread anymore on a regular basis I still want to share TE information and encourage an exchange of knowledge and discussion. I still follow this thread on an intermittent basis but I exclusively post on another forum. But to bring everyone up to date here is what I've been working on. Summary format but I posted links if you want more detail.

First up. A Tek 2235 found on my local CL. Needed some minor work and PSU recap.



Detail:

https://groups.io/g/tea/message/309?p=%2C%2C%2C20%2C0%2C0%2C0%3A%3Arecentpostdate%2Fsticky%2C%2C2235%2C20%2C2%2C40%2C93256403

Next a Sony/Tek 314 from Ebay. Also needed some minor work. A PSU recap is pending.



Detail part 1:

https://groups.io/g/tea/message/2264?p=%2C%2C%2C20%2C0%2C0%2C0%3A%3Arecentpostdate%2Fsticky%2C%2C314%2C20%2C2%2C0%2C94393482

Detail part 2:

https://teanonymous.com/f1/viewtopic.php?t=13


Tek 500 Series Type CA Vertical Plug-in with terrible DC Balance.



Detail:

https://teanonymous.com/f1/viewtopic.php?t=16

Tek 500 Series Type 53/54K Vertical Plug-in from Ebay. Was in good condition but some Gorilla totally messed up the calibration.



Detail:

https://teanonymous.com/f1/viewtopic.php?t=41


Heathkit IG-18 Audio Generator from local CL. Needed work to get it running properly.



Detail:

https://teanonymous.com/f1/viewtopic.php?t=50

Verification of my "Bench Standards"



Detail:

https://teanonymous.com/f1/viewtopic.php?t=66


Update to a Tek Type 310A Fan Mount.



Detail:

https://teanonymous.com/f1/viewtopic.php?t=87

And finally. Tek Type 547 HV Transformer issues. This is an ongoing project with regular updates.



Detail:

https://teanonymous.com/f1/viewtopic.php?t=34

Feel free to post up questions and I'll gladly answer them.

[DH7DN]

While I don't participate in this thread anymore on a regular basis I still want to share TE information and encourage an exchange of knowledge and discussion. I still follow this thread on an intermittent basis but I exclusively post on another forum. But to bring everyone up to date here is what I've been working on. Summary format but I posted links if you want more detail.

First up. A Tek 2235 found on my local CL. Needed some minor work and PSU recap.



Detail:

https://groups.io/g/tea/message/309?p=%2C%2C%2C20%2C0%2C0%2C0%3A%3Arecentpostdate%2Fsticky%2C%2C2235%2C20%2C2%2C40%2C93256403

Next a Sony/Tek 314 from Ebay. Also needed some minor work. A PSU recap is pending.



[...]

Detail:

https://teanonymous.com/f1/viewtopic.php?t=34

Feel free to post up questions and I'll gladly answer them.

Thanks for posting here, I really appreciate it! :-)

[tautech]

Email sent to Siglent N.A. with pic regarding bad probe.

Using Tek PG501 pulse gen, to compare the new SDS2202X-E with the Old Girl DS1054Z. She's been opened up to 100 MHz but I measured the BW to be ~130 MHz. 50 ohm termination attached to input of DS1054Z.

Both results combined into one pic with measurements displayed.

Ya missed what I offered before, for Siglent screenshots just use the blue Print button with which you can keep the appropriate settings menu in shot whereas you lose them using the Save/Recall menu.

Here's one with a dicky coax connection and as I said you need 3 hands to properly capture these and you give them a wiggle and ensure it's not the grabber hat connection that's causing the waveform corruption.

[Vince]

First up. A Tek 2235 found on my local CL. Needed some minor work and PSU recap.

Wow, Papa smurf is back, happy new year !   

Lucky fdind this local 2235.... Neomys could do with one ! Trying hard to find one locally in decent nick at a decent price in working order... it's not easy.

Tek 500 Series Type 53/54K Vertical Plug-in from Ebay. Was in good condition but some Gorilla totally messed up the calibration.



Detail:

https://teanonymous.com/f1/viewtopic.php?t=41

He looks very cute 


About that 547 HV tranny, it broke my heart when I read how much money you spent / wasted with that guy in Germany and his mysterious miracle "treatment"....   

I have two of these 547 which I will eventually get round to working on one day... I am crossing fingers not to have a dodgy tranny.... will be reading your adventures to improve my chances of success, or at least save myself from wasting money and/or time doing this or that.

[xrunner]

Ya missed what I offered before, for Siglent screenshots just use the blue Print button with which you can keep the appropriate settings menu in shot whereas you lose them using the Save/Recall menu.

Oh that blue print button ... 

All I noticed was the blue button "Auto Setup" which I thought must have a second function for you to suggest it, but I was going to look into it later. Now I see the light blue button at the bottom, which doesn't have a black label, so I blinded myself to it. 

Here's one with a dicky coax connection and as I said you need 3 hands to properly capture these and you give them a wiggle and ensure it's not the grabber hat connection that's causing the waveform corruption.

Jason of Siglent NA received my email and is sending me a new probe. So, I'm impressed with customer service.