Test Equipment Anonymous (TEA) group therapy thread

[tautech]

P.S. all the offensive comments on the other site from tautech, I will now recommend Rigol over Siglent.

Re. Tautech, An interesting stance to take by someone who relies on their public image to run a business... 
Meh, whatever.

Oh FFS am I prohibited from having a personal opinion on any matter ? 

Have you learnt nothing from the last few days, this shit is OT here and should you wish to explore it elsewhere that is the correct place to do so ! 

Maybe keeping a separate account for personal opinions would be fine, just not sure calling folk on here Wayne Kerr s helped either, call us Rigol instead. 

Back to sorting the random ICs I got in January.

David

Where have you been man ?
Dual accounts are not permitted here !

One only imagines those you engage with have the intelligence to decipher when an official statement is made vs a personal comment.
How have you got this far in life ?

[tggzzz]

From Ebay, Ukraine.. and it arrived.
1, 10, 100, 1000, 10.000, 100.000    0.01%
Trustable seller .. hope he stays safe:  any-devices

Some resistors similar to those have extra temperature compensation resistances. Such devices are meant to be used in 4W mode with a separate wire going to each terminal.

See what happens if you do the measurement with four separate wires, the drive wires connected to the I terminals and the sense wires to the U terminals.

[Neomys Sapiens]

Seems to be a few of those Tek J16 photometers on ePay, along with a newer J17 model, all seem to have the same problem, the vanishing probe, hope you manage to find one.
 
David

This problem is also very common with any sort of instrument for the measurement of magnetic field strength or flux density. There are only two kinds offered: those with a comment 'probe not included' and those where the seller was completely oblivious that they need one.

This reminds me to finally order the missing lateral probe for my Lake Shore Cryotronics Gaussmeter.
Currently, I only have the axial one. I will include the nulling aid (zero flux chamber) and test magnet too.
When complete, I'll show it again - and a strange beast from this category as well.

[Vince]

Couldn't help, these cool exotic LED displays are just too intriguing... I could not go to sleep, I HAD to play with them !

So I wired one up on a bread board.... and I thought hey, 8 segments, that's also  an ideal pretext to use one of those cool white ceramic resistor arrays as well, what a combo that would make !

... but I had to give up on the latter. Would have made for a big mess of wires and I would not even have had enough Dupont wires to wire it all up anyway !    So instead I did the more sensible thing, and used one of the SIL packages instead... plenty to chose from in 9 pin configuration.... picked a 120R one. I measured all 8 of them and I was surprised to see just how close to nominal they measured ! Some were dead on, and all others were within 0.5% ! 

As for the display itself, first I tried to buzz it with the DMM, to double-check the pinout diagram ch_scr gave me and.... I found that all segments were open-circuit ?!    Tried another display... same again. Reversed polarity just in case I got some common cathode variant instead of the common anode depicted in the diagram... still no joy.  Weird.

So I wired the display anyway, and put a DMM in series with the lab supply to monitor current... don't want to blow my previous vintage displays you see !
ch_scr said they are rated at 20mA or so, so I targeted that. 8 segments... that's 160mA total then.

At first I got zero current, still no life in them..so I slowly upped the voltage, whilst anxiously monitoring current at the same time and... the decimal point starting glowing faintly.. then some more.... then the 7 segments starting coming on finally as well.... upped voltage to much more than I thought algebra would allow... until I got to 160mA, and all the segments were nice and bright.

THEN... Eureka moment... since each segment is composed of two half segments... that means TWO diode drops per segment ! That's why my DMM said open circuit when I tried to buzz the display ! Also why I got zero current flowing when the power supply was set at a voltage that SHOULD have been adequate.... for a NORMAL display.....

Geez, trap for young players as Dave would say ! 

Works all fine now, look at that ! 

My camera is incapable of taking a decent picture that would make justice to the display... took me 20 attempts to get the half decent pic below. Bloody camera keeps washing out everything, and it insists on seeing pink colours where me the human sees red... 
Maybe time for a new camera.... no, not anytime soon, these things are expensive...

Anyway, they work fine and look nice, I can definitely use them in some design of mine at some point 

Yes, the decimal point uses only one diode / element, so it's brighter / gets more current... in real life I would need to a use separate, higher value resistor for that decimal point, so that it gets the same current as the 7 segments.

[Neomys Sapiens]

Couldn't help, these cool exotic LED displays are just too intriguing... I could not go to sleep, I HAD to play with them !

So I wired one up on a bread board.... and I thought hey, 8 segments, that's also  an ideal pretext to use one of those cool white ceramic resistor arrays as well, what a combo that would make !

I would have offered to translate the info from 'Richi's Lab' for you, but you found out anything already, I think.

You can postpone the sorting of the resistor arrays - you have some more coming soon.

[Vince]

Oh, Danke very much ! 

[Brumby]

Every time I see Vince here, I wonder what he's sorting this time...  It seems this is what he's doing half the time.

I don't know if I want to encourage him to stop and smell the roses occasionally .... or send him a box of suitably jumbled components.   

[TERRA Operative]

Hey hold on you two !!

What is this TDS 580C you are talking about as if it were a given ?!

I have never heard of a TDS 580C before, you see !

I just checked on TekWiki and EVEN there it's not listed !!   

So.... I googled... and even Google was not too clued either ! It did find me some 32 page Tektronix document called " TDS 580C supplement ".... which says it's basically a monochrome version of the TDS 784C  ?!.... How come I never heard of this one, and how comes it's not even listed on TekWiki ?!  Was it  reserved to some markets like Japan ??

Here it is!

https://w140.com/tekwiki/wiki/TDS580

[TERRA Operative]

It's this one here:



It's been sitting in the shelves right behind, where the RTB now resides, for several years. But however, the RTB sees more usage than the TDS580C ever has seen at my place.

Anyway, this particular one has undergone some mods, so now it thinks it's a TDS784, but still has a B/W monitor built in. The VGA output is colour now, but an internal NuColor monitor wouldn't work with this one because I didn't fit the required RAMDAC. You'll find some posts how this mod was done somewhere here in the forum ...
Edit: https://www.eevblog.com/forum/repair/conversion-tektronix-tds500-to-tds700-color-oscilloscope/msg2920902/#msg2920902

Want a RAMDAC? I got a spare RAMDAC chip and if I dig around, I might even have some spare video RAM here too if you want to make the last step... (Assuming you have a colour display, I got no working spares of those..)

[TERRA Operative]

Seems to be a few of those Tek J16 photometers on ePay, along with a newer J17 model, all seem to have the same problem, the vanishing probe, hope you manage to find one.
 
David

This problem is also very common with any sort of instrument for the measurement of magnetic field strength or flux density. There are only two kinds offered: those with a comment 'probe not included' and those where the seller was completely oblivious that they need one.

This reminds me to finally order the missing lateral probe for my Lake Shore Cryotronics Gaussmeter.
Currently, I only have the axial one. I will include the nulling aid (zero flux chamber) and test magnet too.
When complete, I'll show it again - and a strange beast from this category as well.

That's exactly the case I am in here too.
Aaaggeess ago I got given a free AD-S gauss meter model HGM-8300 LW when I was purchasing a HP 4275A LCR meter (that I got for a song, pickup only on my way to work so I was the only bidder, like 1000yen... )
It has no probes.... 

[EDIT]
Great, now I'm sending off emails for a quote on a probe and zero chamber for this thing. 

[capt bullshot]

It's this one here:



It's been sitting in the shelves right behind, where the RTB now resides, for several years. But however, the RTB sees more usage than the TDS580C ever has seen at my place.

Anyway, this particular one has undergone some mods, so now it thinks it's a TDS784, but still has a B/W monitor built in. The VGA output is colour now, but an internal NuColor monitor wouldn't work with this one because I didn't fit the required RAMDAC. You'll find some posts how this mod was done somewhere here in the forum ...
Edit: https://www.eevblog.com/forum/repair/conversion-tektronix-tds500-to-tds700-color-oscilloscope/msg2920902/#msg2920902

Want a RAMDAC? I got a spare RAMDAC chip and if I dig around, I might even have some spare video RAM here too if you want to make the last step... (Assuming you have a colour display, I got no working spares of those..)

Thanks, but no. Don't have a NuColour display and (at least ATM) I'm not planning to acquire more of these TDS series.

[Robert763]

Re. Tautech, An interesting stance to take by someone who relies on their public image to run a business... 
Meh, whatever.


On the TEA front, I just bought this Tek J16 Digital Photometer.
Once I get a sensor head for it (or figure out how to make one...) I plan to use it to set the correct screen brightness when calibrating and adjusting TDS600 and 700 series scopes.

Sorry, late to this.
The J16 is just a picoammeter. The probe is just a photo diode and lens. IIRC the is also a link and calibration resistor to set the correct range. Any decent photodiode will do the job.

[Vince]

Hey hold on you two !!

What is this TDS 580C you are talking about as if it were a given ?!

I have never heard of a TDS 580C before, you see !

I just checked on TekWiki and EVEN there it's not listed !!   

So.... I googled... and even Google was not too clued either ! It did find me some 32 page Tektronix document called " TDS 580C supplement ".... which says it's basically a monochrome version of the TDS 784C  ?!.... How come I never heard of this one, and how comes it's not even listed on TekWiki ?!  Was it  reserved to some markets like Japan ??

Here it is!

https://w140.com/tekwiki/wiki/TDS580

Thanks ! But..... if there is a page for it..  and it looks decent enough as it is to be published.... why haven't they linked to it on the main page with all the other scopes models ?! People won't know about it unless it appears on the main page ..

Maybe you can fix that !

[Vince]

Every time I see Vince here, I wonder what he's sorting this time...  It seems this is what he's doing half the time.

I don't know if I want to encourage him to stop and smell the roses occasionally .... or send him a box of suitably jumbled components.   

Sorting components is a mandatory step before I can use them to design anything ! 

... but I AM doing other things in parallel... have resumed work on my Nik-c DVM the other day, hey ! 

[Vince]

Re. Tautech, An interesting stance to take by someone who relies on their public image to run a business... 
Meh, whatever.


On the TEA front, I just bought this Tek J16 Digital Photometer.
Once I get a sensor head for it (or figure out how to make one...) I plan to use it to set the correct screen brightness when calibrating and adjusting TDS600 and 700 series scopes.

Sorry, late to this.
The J16 is just a picoammeter. The probe is just a photo diode and lens. IIRC the is also a link and calibration resistor to set the correct range. Any decent photodiode will do the job.

Yes but I don't understand... the instrument is calibrated / designed to use a particular photodiode /glass/housing etc... slapping any random photo-diode sure will display "something" on the instrument, but it will mean nothing.

It's like, I guess, those old HP analog RF power meters that go for super cheap because they are worthless without the RF power sensor that goes with them, no ?

Trying to understand...

[ch_scr]

Re. Tautech, An interesting stance to take by someone who relies on their public image to run a business... 
Meh, whatever.


On the TEA front, I just bought this Tek J16 Digital Photometer.
Once I get a sensor head for it (or figure out how to make one...) I plan to use it to set the correct screen brightness when calibrating and adjusting TDS600 and 700 series scopes.

Sorry, late to this.
The J16 is just a picoammeter. The probe is just a photo diode and lens. IIRC the is also a link and calibration resistor to set the correct range. Any decent photodiode will do the job.

Yes but I don't understand... the instrument is calibrated / designed to use a particular photodiode /glass/housing etc... slapping any random photo-diode sure will display "something" on the instrument, but it will mean nothing.

It's like, I guess, those old HP analog RF power meter that go for super cheap because they are worthless without the RF power sensor that goes with it, no ?

Trying to understand...

The "magic" is not the photodiode per-se but the filter before it, giving it either a broadband flat response, or one similar to the sensitivity of the human eye. Attached below is page three of the manual that explains this and the curves from two of the probes. A "CIE response photodiode" or an "eye response detector" should be obtainable. But all the optics stuff is obviously an rabbithole in itself!
Edit: I've added the page of the Hamamatsu catalogue with possible candidates, maybe TERRA can walk over and ask for a sample or two

[Vince]

Thank you very moosh, interesting read ! 

So looks like as you say the diode itself is not a problem because, from the documents you posted....we don't just use any photo-diode, but rather ones made specifically for use in photmeters.... therefore tehy come with a built-in filter and are all made to have the same sensitivty of 0.3A/W according to that catalogue you showed.
That's very handy then...

I guess now all one would need to make a probe, is to no the size / area of the aperture used in the Tek probe (the diameter of the hole in the probe housing at the front...) so that we can make sure the home made probe gets the same amount of light than the Tek probe, hence will give the same current output for a given brightness.

The wavelength response plot is interesting as well...shows that these things really are NOT accurate at all to begin with !  +/- 7% "ripple" in the pass band ! 
So I guess any measurement is to be taken with a grain of salt....

Still useful to make comparisons though. No matter how bumpy the curve looks like, if you use the same test pattern on the CRT, then whatever the sensitivity is at that particular wavelength, it won't change between measurements, so you can still rely on it. You don't really need to measure how much light you get.... only to make sure that you put the same amount, whatever it really is physically, to all the scopes / CRT.

OK OK.....

[EEVblog]

Important POLL:
https://www.eevblog.com/forum/testgear/tea-moderation-poll/

[ch_scr]

Thank you very moosh, interesting read ! 

So looks like as you say the diode itself is not a problem because, from the documents you posted....we don't just use any photo-diode, but rather ones made specifically for use in photmeters.... therefore tehy come with a built-in filter and are all made to have the same sensitivty of 0.3A/W according to that catalogue you showed.
That's very handy then...

I guess now all one would need to make a probe, is to no the size / area of the aperture used in the Tek probe (the diameter of the hole in the probe housing at the front...) so that we can make sure the home made probe gets the same amount of light than the Tek probe, hence will give the same current output for a given brightness.

The wavelength response plot is interesting as well...shows that these things really are NOT accurate at all to begin with !  +/- 7% "ripple" in the pass band ! 
So I guess any measurement is to be taken with a grain of salt....

Still useful to make comparisons though. No matter how bumpy the curve looks like, if you use the same test pattern on the CRT, then whatever the sensitivity is at that particular wavelength, it won't change between measurements, so you can still rely on it. You don't really need to measure how much light you get.... only to make sure that you put the same amount, whatever it really is physically, to all the scopes / CRT.

OK OK.....

It's all a bit more complicated (as rabbit holes tend to be) - look closely, all the "CIE" curves (and even the flat one) are labeled in "relative sensitivity percent" - nothing about how much current comes out! Luckily the gain resistor is in the handle as well and as long as you're "in the ballpark" it should be adjustable to make it fit. The optical arrangement might be a bit more involved with a lens or two as well, one would have to have a closer look on the specific probe to be recreated and it's specifics.

[TERRA Operative]

Hey hold on you two !!

What is this TDS 580C you are talking about as if it were a given ?!

I have never heard of a TDS 580C before, you see !

I just checked on TekWiki and EVEN there it's not listed !!   

So.... I googled... and even Google was not too clued either ! It did find me some 32 page Tektronix document called " TDS 580C supplement ".... which says it's basically a monochrome version of the TDS 784C  ?!.... How come I never heard of this one, and how comes it's not even listed on TekWiki ?!  Was it  reserved to some markets like Japan ??

Here it is!

https://w140.com/tekwiki/wiki/TDS580

Thanks ! But..... if there is a page for it..  and it looks decent enough as it is to be published.... why haven't they linked to it on the main page with all the other scopes models ?! People won't know about it unless it appears on the main page ..

Maybe you can fix that !

I must have missed it when I was making and editing these pages. There are a couple more to make here and there too. And I haven't even got close to the 300 and 400 series yet (Not something I've looked at purchasing seeing as I have so many 600 and 700 series. )

Re. Tautech, An interesting stance to take by someone who relies on their public image to run a business... 
Meh, whatever.


On the TEA front, I just bought this Tek J16 Digital Photometer.
Once I get a sensor head for it (or figure out how to make one...) I plan to use it to set the correct screen brightness when calibrating and adjusting TDS600 and 700 series scopes.

Sorry, late to this.
The J16 is just a picoammeter. The probe is just a photo diode and lens. IIRC the is also a link and calibration resistor to set the correct range. Any decent photodiode will do the job.

Yes but I don't understand... the instrument is calibrated / designed to use a particular photodiode /glass/housing etc... slapping any random photo-diode sure will display "something" on the instrument, but it will mean nothing.

It's like, I guess, those old HP analog RF power meter that go for super cheap because they are worthless without the RF power sensor that goes with it, no ?

Trying to understand...

The "magic" is not the photodiode per-se but the filter before it, giving it either a broadband flat response, or one similar to the sensitivity of the human eye. Attached below is page three of the manual that explains this and the curves from two of the probes. A "CIE response photodiode" or an "eye response detector" should be obtainable. But all the optics stuff is obviously an rabbithole in itself!
Edit: I've added the page of the Hamamatsu catalogue with possible candidates, maybe TERRA can walk over and ask for a sample or two

I found one of my favourite stores in Akihabara usually has the S7686 in stock, but they are out of stock until February, damn corona and chip shortages....

https://akizukidenshi.com/catalog/g/gI-11780/

[ch_scr]

I found one of my favourite stores in Akihabara usually has the S7686 in stock, but they are out of stock until February, damn corona and chip shortages....

https://akizukidenshi.com/catalog/g/gI-11780/

Better tell them to reserve you one or two lest they will be sold out again    Have you figured out which sensor head you want to mimic? More because of the rest of the optical system - I'd expect them to give a distance to place the sensor in front of the screen, kind of like a focus distance on a fixed projection lens? (here working in reverse) But I'm just guessing and with lenses im in wayyyyy above my head.

[TERRA Operative]

I think the J6503 sensor head would get me out of trouble.

I reckon one of those S7686 sensors when I can get my hands on one stuck at the end of some aluminium pipe painted black, mounted inside maybe a 3D printed or formed sheet aluminium enclosure with a lens or two here and there might just be able to replicate the original sensor pretty well hopefully.

[m k]

I have an admission to make:
At the home of my late dad was a Kaise SK-550 analog meter for reasons unknown to me, he was a electrician but of the modern kind.
But recently I could not let that meter just sit there, I had to take it to my home, it looked quite nice on the facia:

(it's not exactly sunny day here but dang)

My Kaise seems to be drop proof.
It's last active duty was being a short indicator of mains variac.
Leak tube effect is blue and one finger has been stuck at least once.
Flash is also giving much better picture of PCB contacts.

BTW,
can't find cases for my other test equipment.

[m k]

How is that other copy protection, still unknown?

No. Using IBM34 format:

• Cylinders 0...76 both heads are formatted normally
• Cylinder 77 both heads and 78 head 0 is not formatted
• Cylinder 78 head 1 is formatted with sector marks track=150, sector id=17...32 (WD is instructed to NOT verify track id)
• Cylinder 79 both heads is formatted with sector marks track=79, sector id=96...111

So the 2nd, "Application denied" and possible LIF directory thing, was not really there and everything was in those last tracks?
I saw from your video that formatting wrote something more around 1/3 location and thought it can be a root directory.

Since I have few old drives and even couple A500s, if I get an original program disk can I make a working and possibly installing image, even for different device using these protection methods?

[factory]

Not done much today, listed a few more from the bag of random ICs into LibreOffice Calc, triggered the google "we think you are a robot" crap many times today looking them up  , got 164 done so far.

Also unboxed the parcels that have arrived recently.



First is a Hioki 8220 Multi Hi-Play with the original box & leads, this is a dual channel volt/amp meter with recording function, well at least it would be if it wasn't completely dead  , it does nothing fitted with leak-tubes, or connected to the mains PSU, another for the lengthy repair queue.





Second is a Racal 9523 VLF counter/timer, advertised as we haven't got a power lead & can't test it, it's in nice condition and seems to have two defective numerical bulbs, this shouldn't be a problem as I still have a couple of spare Racal readout boards (acquired years ago).





Next is a 200MHz HP 5258A sensitive prescaler plug-in for the 524x series counters, not one I've seen for sale before and finally a 700°C Hitachi K type temperature probe.





David