Test Equipment Anonymous (TEA) group therapy thread

[ch_scr]

[...]

This beautiful drawing just reminded me to remind you of this:
https://github.com/scanlime/davecad

[McBryce]

Picked up a quirky little counter on a maiden bid this last week, largely to keep it away from the nixie clock wankers.



It needs a little fettling; the power switch is jammed on for one thing, and I think all the controls could benefit from some contact cleaner, the BNCs as well.


Ironically enough, while I was playing with it I got the idea that it would be an interesting challenge to make it work as a clock display, without modifying it in any way...   

Nixie Clock builders rarely take Nixies from meters. There's tons of sellers in eastern Europe that sell NOS Nixie tubes.

McBryce.

[Cerebus]

LOL... My dad keeps telling me he's like a carbon-copy duplicate of me when I was a kid. He certainly has the attitude, and the tendency to be utterly oblivious to the world around him. Every once in a while, tho... mother and I are able to impinge upon his existence on "Planet Marcus"; this seemingly normal snapshot is one of them.

mnem
"Eh.... he's a teenager. He won't be human again til his 30s... if he lives that long." ~mom to mom-mom

Serendipity moment: I've just seen a bloke on the telly in a  Vox-pop in Oban, Scotland who looks just like I expect Marcus will in 10-15 years. Incidentally he was standing not 200 yards from where I was sleeping on the night of 11th Sept. 2001.

[mnementh]

Ironically enough, while I was playing with it I got the idea that it would be an interesting challenge to make it work as a clock display, without modifying it in any way...   

I've suggested that as a project in here several times. 

mnem
"Sick minds think alike. And you're more likely than most..." ~grand-dad

Extra kudos points if you can do it by tickling the VCO input of a 555

   https://shop.evilmadscientist.com/productsmenu/tinykitlist/652#

mnem 
 

      https://shop.evilmadscientist.com/directory

Oh hey... looks like he's added SMD soldering kit versions of his "dis-integrated" 555 and 741 IC gadgets... some nice soldering meditation right there. 

Smaller package, tho... not as impressive on the bench. 

mnem
 

[factory]

   https://shop.evilmadscientist.com/productsmenu/tinykitlist/652#

mnem
 

Interesting, but if you're going to emulate a 555 with discrete devices, then for a nixie clock project you need to use toobs...

Been done before; http://www.jogis-roehrenbude.de/Leserbriefe/Bruegmann-Digital-Roehren-Clock/Digital-Roehrenuhr.htm

David

[AVGresponding]

Ironically enough, while I was playing with it I got the idea that it would be an interesting challenge to make it work as a clock display, without modifying it in any way...   

Then your next step is to decide how hard a challenge you want:

• Easy - Frequency controlled - digital - based around a DDS or similar
• Easyish - Frequency controlled - digital - based around generating the right pulse train.
• Middling - Timing controlled - digital - based around just generating the right pulse width with an MCU
• Hard - timing controlled - analogue controlled pulse generator with a digital source of "time"
• Fiendishly hard - timing controlled - analogue controlled pulse generator with an analogue source of "time"

Using a microcontroller of any sort seems like cheating; you may as well just directly drive those OLED fake nixies with one.

Fiendishly hard is not wrong. It would need frequencies from zero to, say, 2.359MHz in 1439 discrete 1kHz steps, and of course jumping from **59 to **00 at the turn of each hour, so missing the **60 to **99 steps.
You could simplify it a bit by doing a 12 hour clock but I'm too used to 24 hour clocks.

Building it out of discrete TTL/CMOS ICs would be about as difficult as I'd like to get...

[AVGresponding]

   https://shop.evilmadscientist.com/productsmenu/tinykitlist/652#

mnem
 

Interesting, but if you're going to emulate a 555 with discrete devices, then for a nixie clock project you need to use toobs...

Been done before; http://www.jogis-roehrenbude.de/Leserbriefe/Bruegmann-Digital-Roehren-Clock/Digital-Roehrenuhr.htm

David

That's great! You're definitely not going to be running that on a single AA like most wall clocks though!   

[factory]

Picked up a quirky little counter on a maiden bid this last week, largely to keep it away from the bulb clock wankers.



It needs a little fettling; the power switch is jammed on for one thing, and I think all the controls could benefit from some contact cleaner, the BNCs as well.


Ironically enough, while I was playing with it I got the idea that it would be an interesting challenge to make it work as a clock display, without modifying it in any way...   

Bulb Clock builders rarely take bulb from meters. There's tons of sellers in eastern Europe that sell NOS bulb tubes.

McBryce.

Greedy ePay sellers certainly do, seen some nice 8 digit 1960's counters from Marconi & Grundig that were parted out after not selling at inflated prices.

David

[mindcrime]

Last time I ordered these was from evilbay. Aliexpress's search SUCKS more than SMF's native one does here 

add 10pcs into your search so like this listing eBay auction: #153431509958

There are numerous sellers offering these (or ones that look like these) and the pricing per unit can vary - but the shipping costs can also vary.  I went through a couple of dozen stores checking out the price + postage for the 50 I had in mind.  For this many, the variations of item price and shipping were usually complementary, with the total cost being fairly similar.  There were some where the automatically calculated shipping cost was stupidly high, but I found one that was a little better than most - and that's who I went with:

https://www.aliexpress.com/item/1005002376851939.html

Awesome, thanks!

[Cubdriver]

Greedy ePay sellers certainly do, seen some nice 8 digit 1960's counters from Marconi & Grundig that were parted out after not selling at inflated prices.

David

Yep.   

-Pat

[ch_scr]

[...]
timing controlled - analogue controlled pulse generator with an analogue source of "time"

Lets get it straight: timing controlled means "pulsewidth equals time in digital"?
like 1158ms, 1159ms then jump to 1200ms?
Also, what would be considered an "analogue source of time"? 10Mhz or 50Hz sinewave from outside? RC or LC oscillator?
Edit: On second thought, a delay line would be analogue for sure?

[tggzzz]

Ironically enough, while I was playing with it I got the idea that it would be an interesting challenge to make it work as a clock display, without modifying it in any way...   

Then your next step is to decide how hard a challenge you want:

• Easy - Frequency controlled - digital - based around a DDS or similar
• Easyish - Frequency controlled - digital - based around generating the right pulse train.
• Middling - Timing controlled - digital - based around just generating the right pulse width with an MCU
• Hard - timing controlled - analogue controlled pulse generator with a digital source of "time"
• Fiendishly hard - timing controlled - analogue controlled pulse generator with an analogue source of "time"

Using a microcontroller of any sort seems like cheating; you may as well just directly drive those OLED fake nixies with one.

Fiendishly hard is not wrong. It would need frequencies from zero to, say, 2.359MHz in 1439 discrete 1kHz steps, and of course jumping from **59 to **00 at the turn of each hour, so missing the **60 to **99 steps.
You could simplify it a bit by doing a 12 hour clock but I'm too used to 24 hour clocks.

Building it out of discrete TTL/CMOS ICs would be about as difficult as I'd like to get...

You will occasionally need the **60 step.

[mansaxel]

Extra kudos points if you can do it by tickling the VCO input of a 555

That is outright sick.

[Cerebus]

[...]
timing controlled - analogue controlled pulse generator with an analogue source of "time"

Lets get it straight: timing controlled means "pulsewidth equals time in digital"?
like 1158ms, 1159ms then jump to 1200ms?

That sort of thing, yes.

Also, what would be considered an "analogue source of time"? 10Mhz or 50Hz sinewave from outside? RC or LC oscillator?
Edit: On second thought, a delay line would be analogue for sure?

I was think more along the lines of a precision \$11.574\dot{0}7\dot{4} \mu Hz\$ sawtooth wave was the initial input. 

[ch_scr]

[...]
timing controlled - analogue controlled pulse generator with an analogue source of "time"

Lets get it straight: timing controlled means "pulsewidth equals time in digital"?
like 1158ms, 1159ms then jump to 1200ms?

That sort of thing, yes.

Also, what would be considered an "analogue source of time"? 10Mhz or 50Hz sinewave from outside? RC or LC oscillator?
Edit: On second thought, a delay line would be analogue for sure?

I was think more along the lines of a precision \$11.574\dot{0}7\dot{4} \mu Hz\$ sawtooth wave was the initial input. 

Precisely delivered via the push of a button to keep it going I suppose?
Edit: but on a more serious note, i thought maybe a delay line and an 1-sec RC adding periodically to the pulse length and a second 60 sec RC adding a bit more to get it to jump up 39+1 tick... something something?

[Cerebus]

Precisely delivered via the push of a button to keep it going I suppose?

Easily done by getting a small boy to press the button while watching the globe drop at the Greenwich Observatory^* through a telescope, when he wasn't otherwise employed cleaning chimneys and the like.

^*I don't know whether they still do this - it's the sort of thing that carries on well after its purpose is gone. It was done so that ships anchored in the Pool of London could set their chronometers by training a spyglass on the observatory.

I just checked, they do still operate it.

The bright red Time Ball on top of Flamsteed House is one of the world's earliest public time signals, distributing time to ships on the Thames and many Londoners.
The Time Ball was first used in 1833 and still operates today. Normally each day, at 12.55pm, the time ball rises half way up its mast. At 12.58pm it rises all the way to the top. At 1pm exactly, the ball falls, and so provides a signal to anyone who happens to be looking.

[Specmaster]

I hope that it was one of you that beat me for this collection https://www.ebay.co.uk/itm/Job-Lot-of-Test-Equipment-/274810557905?, I was just out bid for this group. Whoever it was, good job and well done to you.

[BU508A]

Some today arrivals.

Top left: nice Vishay 1MOhm 0.005% resistors (not for me, will forward them to a TEA fellow  )

top middle-right: DC-DC step-down buck converter with voltage display
bought here: https://www.ebay.com/itm/313493568554

The rest: a very nice compilation from ch_scr! Thank you! 
Some PCBs for the AD587UQ and parts. 

Glad it arrived well, here's the help for putting the components on:
Note  : where the 2 parallel 100R's reside is the trim for the "farther than the other" AD587.
The one thats off the other way got 2 in series. On the three other ones just one 100R and a bridge for the trimpot was "good enough"
Note 2: The place that looks like it wants to have the 100R SMD trim, needs a bridge. The cut away trace gets the 100R.
(As seen in the picture below) Go figure 
Note 2.5: The solder pads for the ferrite beads are a bit short, but you'll find a way to get them on I'm sure 
Note 3: "Every solder job looks shoddy, given you magnify enough" ~ proverb of the magnifier salesman
Have fun!

I've drawn a little schematic. To your eyes, does it look correct?

The two parallel 100 Ohms resistors are in my schematic R1, right?

First glance says: except L3's a diode it's correct
Edit says: good job on the davecad 

 
Of course it is a diode, not a choke!    You've mentioned some protection in discord. D'oh!
Btw, this is the backside of the schematices:

On mid of May I've received four of those nice Vishay 1MOhm resistors. The same day another envelope from the seller (zhoefler, ebay) arrived and I was wondering about that, because I didn't expect another delivery from him. Opened the envelope and found some high voltage capacitors. The invoice mentioned clearly another customer of him in Leverkusen. I called Mr Hoefler and told him, that I got the capacitors of this customer of him and told him, that I will forward them to the guy in Leverkusen. He was very pleased about that and offered me a "little" reward for my efforts. I said: "Yes, thank you, that's very kind from you." thinking, that he will send me some various electronic parts.

Some days later a parcel from Mr. Hoefler arrived. I opened it and found this:
- a Pt100 simulator from burster präzisionsmeßtechnik in Gernsbach (it was already torn apart when I've received it)
- a modular resistor decade from burster (the 100Ohms module is missing and the 100kOhms module was torn apart)

Wow!  THAT was really a surprise, didn't expect that! 

Let's start with the Pt100 simulator. Essentially, it consists of 30 high precision 0.02% resistors and a 30 step high quality switch.

The front, backside of the front, the PCB and a detailed view of the resistors being used:


I haven't tested it yet but I assume, that the switch will be happy about some cleaning.

Next is the burster resistor decade which I do really like for its modular design.
Top view, the disassembled 100k resistors and the backplane:


I've checked the 10k 0.05% resistor module and found a lot of jumping around while wiggling on the knob.
I've opened it and it was clear, where this behaviour is coming from. Really, burster? Attaching directly the switch to the case, where the knob is also being used to lift out the module from the case? I think, the silver contacts are also a problem and need some cleaning.

Module disassembled, side view:


Some detailed views of the switch, a "EBE EMX 1/1 x 11k T=12 Ag"



Have not decided yet what to do with this decade since two modules are missing (the 100Ohm and the 100kOhm one).
I'm a bit reluctant to extract the resistors and use them as some reference resistors, but on the other side I'm not sure, if one can trust those poor switches anymore. Even if cleaning will work, I'm not so sure about the mechanical abuse.

What do you think?

Thank you for watching, hope you've enjoyed this "little" surprise of mine. 

[med6753]

The Type 454 PSU re-cap.

It doesn't look like much but it took many hours to get the two original cans out and the new installed. One whole row of rectifiers had to come out just to get to the mounting screws for the cans. But those 2 are finally done. The 2 remaining cans in the back will be much easier as their mounting screws are accessible. That's for tomorrow.

 

[mansaxel]

<snip>
Some days later a parcel from Mr. Hoefler arrived. I opened it and found this:

<snip>

Congratulations! 

<snip>
What do you think?

It's obvious what needs to be done:



 

[mnementh]

mnem
*knocks self unconscious with a gagh mallet*

[beanflying]

No need for a thermometer its June and T-Shirt conditions in the shack 

Assorted non TEA Cad stuff for no good reason heading to the Laser.

Small box jig for glue ups as its way to fiddly to clamp little bits. Recent small bench bit boxes were the cause  Mainly for Wooden/PVA boxes but also will get some acrylic use.

Tweaked from an online plan a Slimline leather card wallet as my old full sized one is about worn out and I don't need the room in a modern era. Space for 3-4 cards and a few notes. Laser cut and hand stitched

[beanflying]

Definition of 'Scorching' so hot your Beer will get warmer faster in the UK. 

A scorching 25.7C (78.3F) was recorded at Heathrow Airport at 2pm on Tuesday, surpassing the 25.1C (77.2F) - the previous hottest day of the year temperature - set in Kinlochewe, Scotland, on Bank Holiday Monday

https://news.sky.com/story/uk-weather-country-records-hottest-day-of-the-year-and-it-could-get-sunnier-despite-thunderstorm-threat-12322510

[med6753]

Definition of 'Scorching' so hot your Beer will get warmer faster in the UK. 

A scorching 25.7C (78.3F) was recorded at Heathrow Airport at 2pm on Tuesday, surpassing the 25.1C (77.2F) - the previous hottest day of the year temperature - set in Kinlochewe, Scotland, on Bank Holiday Monday

https://news.sky.com/story/uk-weather-country-records-hottest-day-of-the-year-and-it-could-get-sunnier-despite-thunderstorm-threat-12322510

That's no news here. Now that it's June temperatures at that level, and much higher, will be the norm.

They fuss about a little bit of heat yet Brits won't buy residential A/C units to cool down. "Too little warm days to justify purchasing one" seems to be their mantra. OK, then let the sweat drip off your stiff upper lip.   

[Robert763]

I hope that it was one of you that beat me for this collection https://www.ebay.co.uk/itm/Job-Lot-of-Test-Equipment-/274810557905?, I was just out bid for this group. Whoever it was, good job and well done to you.

Not me I got beaten too.