Test Equipment Anonymous (TEA) group therapy thread

[tggzzz]

I don't  understand the comparison between the two ? I mean they are just different things. 4000 series has a voltage range of 3 to 15V. 74HC / HCT if I believe the datasheet I just pulled, is 2 to 6V.
I understand your points, taken...but if I need to supply the logic for whatever reason above 6V, I am screwed with 74-anything.
Or if the circuit doesn't have stable supply voltage and the logic cheap needs to be able to operate with a changing supply voltage ?! 

The difference between HC and HCT is solely the input threshold voltage. HC is symmetrical, HCT is 5V TTL compatible.

For familiarity durimg design, the same functions/pinouts are available in both TTL and CMOS devices, which lead to there being, say, 7400 and 74AC00 devices. That continues to this day with many different logic families.

[bd139]

Personally the old CMOS 4000 series are DEAD other than the CD4007 which is still quite useful as it's basically uncommitted MOSFET inverter which can be snuck into various analogue circuits.

The 4000 series have one nice characteristic: operation at IIRC 3V to 15V

Back in the late 70s I used some to build a fllter with a Q of 4000 using 10% capacitors, capable of measuring 1pW using  bog-standard LF351 op amps, and a dynamic range of 180dB (90dB optical).

Yes and no. A lot of the characteristics were wide across the voltage range which was a big problem. A fine example I saw was a car alarm built around a couple of CD4001's. It only worked properly if the battery was above about 11.5 volts. So if you didn't use your car for a few weeks then it'd go off all by itself 

the LF351 / LF411 / TL081 series are a favourite of mine as well. Very very nice opamps. I built a basic thermally compensated log converter with an LF411 and MAT02 array that had good performance. Not that good though.

[mansaxel]

I don't  understand the comparison between the two ? I mean they are just different things. 4000 series has a voltage range of 3 to 15V. 74HC / HCT if I believe the datasheet I just pulled, is 2 to 6V.
I understand your points, taken...but if I need to supply the logic for whatever reason above 6V, I am screwed with 74-anything.
Or if the circuit doesn't have stable supply voltage and the logic cheap needs to be able to operate with a changing supply voltage ?! 

It's probably cheaper now to just chuck a 78L05 in the circuit and be done. That will handle both problems for pocket change.

Don't be so .. practical . That's not fun. 

[Vince]

I don't  understand the comparison between the two ? I mean they are just different things. 4000 series has a voltage range of 3 to 15V. 74HC / HCT if I believe the datasheet I just pulled, is 2 to 6V.
I understand your points, taken...but if I need to supply the logic for whatever reason above 6V, I am screwed with 74-anything.
Or if the circuit doesn't have stable supply voltage and the logic cheap needs to be able to operate with a changing supply voltage ?! 

It's probably cheaper now to just chuck a 78L05 in the circuit and be done. That will handle both problems for pocket change.

Yes again not saying 4000  is better, just saying it's different and it thus allows potentially to do stuff you can't do with a 74 (alone).
It's up to the designer and bean counters to decide if it makes more sense for a particular project to go one route or the other. But at least 4000 series gives you options, and options are always good... 

[tggzzz]

We're all fucked at some point. It's just about controlling how soon as best as possible.

Just found out how much Russia fucked my pension today. 3 years of contributions down the shitter. I've just shit canned all contributions to it in the short term and will spend it on beer, floozies, scopes and power supplies 

Not just Russia, it is the omnicrisis.

At this RPI, my pension will halve in value in about 7 years. And I can't do anything to improve that.

I should become a millionaire next week. Unfortunately since I have a daughter, that will only last a month or so.

Omnicrisis is a good way of putting it.

Similar situation. Alas it's mostly in liquid cash at the moment as it's being consolidated and moved around so when it's in the bank account it's just burning. It worked out better to pay a year's rent in the new place up front than pay monthly. I'll buy something else next year and move into that and ride it for as long as possible.

This week about half my cash is earning 7%. Next week I'll have more cash, but it won't be earning anything like that.

Next year house prices won't go up, and are likely to fall. Doesn't bother me, but sproglet is being forced to buy one within 3 months (no fault eviction, self-employed, with a dog).

Depends where and what. The market I'm entering, in London, has competition from people downsizing from oversized houses into reasonable ones unfortunately. The prices won't be going down here.

Locations and timing are everything, of course. But the concept of downsizing from an oversized house in London eludes me. Getting out of a flat seems bleeding obvious, especially if it is high rise.

But won't you be able to move in with your next redhead?

[Specmaster]

<snip>
Yup.

Just as the new influenza variant just over a century ago was much nastier than its predecessors. That might happen with covid, or might not. This month's variants appear to hit the depths of the lungs more easily and harder, hence the rise in hospitalisations. Next month's?

The point is that it is unwise to act on the presumption that future variants won't be a major problem.

Plus we are all a couple of years older, and that translates to a 25% higher risk (I.e. doubles every 6 years)

Until the WHO says that we can all back to normal living again, I'm 73 now and well aware that I'm in the at risk category and that the risk is going to grow all the time as we age, I intend to keep my guard up and think that we all should do so. Just because our stupid Government no longer talk about it for their own greedy self-serving agenda, it sickens me to see that most of the public think its all over and done with and have stopped all of their precautions. Hence, why we are seeing this rise in cases since the Jubilee celebrations with mass get togethers acting as spreader events and more events coming up like Glastonbury etc which will be putting more of the elderly population at risk, particular those in care homes etc. We never seem to learn from past mistakes   

Indeed, but I'm not sure of the motivation. At some stage we will have to pay the interest on all the money spent during lockdown. It could be that They are refusing to loan the UK money on ter!s that are as favourable as in the past.

I was going to add a snarky joke/observation about this week's news, but that would be too close to being political.

You seem convinced that we actually burrow money from some other country / person. Is it not more likely that as the economy is more a man created thing, that Governments simply instruct the mints to actually print more money and when Governments make repayments, that money goes into Gold reserves and sits in the banks vaults ready for other emergencies?

[tggzzz]

Personally the old CMOS 4000 series are DEAD other than the CD4007 which is still quite useful as it's basically uncommitted MOSFET inverter which can be snuck into various analogue circuits.

The 4000 series have one nice characteristic: operation at IIRC 3V to 15V

Back in the late 70s I used some to build a fllter with a Q of 4000 using 10% capacitors, capable of measuring 1pW using  bog-standard LF351 op amps, and a dynamic range of 180dB (90dB optical).

Yes and no. A lot of the characteristics were wide across the voltage range which was a big problem. A fine example I saw was a car alarm built around a couple of CD4001's. It only worked properly if the battery was above about 11.5 volts. So if you didn't use your car for a few weeks then it'd go off all by itself 

You can do crap brittle design in any technology, hardware or software!

[tggzzz]

<snip>
Yup.

Just as the new influenza variant just over a century ago was much nastier than its predecessors. That might happen with covid, or might not. This month's variants appear to hit the depths of the lungs more easily and harder, hence the rise in hospitalisations. Next month's?

The point is that it is unwise to act on the presumption that future variants won't be a major problem.

Plus we are all a couple of years older, and that translates to a 25% higher risk (I.e. doubles every 6 years)

Until the WHO says that we can all back to normal living again, I'm 73 now and well aware that I'm in the at risk category and that the risk is going to grow all the time as we age, I intend to keep my guard up and think that we all should do so. Just because our stupid Government no longer talk about it for their own greedy self-serving agenda, it sickens me to see that most of the public think its all over and done with and have stopped all of their precautions. Hence, why we are seeing this rise in cases since the Jubilee celebrations with mass get togethers acting as spreader events and more events coming up like Glastonbury etc which will be putting more of the elderly population at risk, particular those in care homes etc. We never seem to learn from past mistakes   

Indeed, but I'm not sure of the motivation. At some stage we will have to pay the interest on all the money spent during lockdown. It could be that They are refusing to loan the UK money on ter!s that are as favourable as in the past.

I was going to add a snarky joke/observation about this week's news, but that would be too close to being political.

You seem convinced that we actually burrow money from some other country / person. Is it not more likely that as the economy is more a man created thing, that Governments simply instruct the mints to actually print more money and when Governments make repayments, that money goes into Gold reserves and sits in the banks vaults ready for other emergencies?

Who did the government pay £7bn interest payments to last month?

Entities that had bought government bonds.

Bond yields depend on confidence.

[mnementh]

Futch...

mnem
 

mnem
*toddles off to ded*

So, for lack of better things that I want to do... I'm going to chronicle this little adventure in TEA...



First on the agenda is cleaning up this filthy beast. You've seen this before pic; well, inside isn't much better. 

   

Careful application of a natural-bristle paintbrush is the first line of assault; this breaks loose almost all of the cruds such that followup with compressed air is actually effective. I'll use it on the vanes and body of the fan, surfaces with a layer of crud, and on PCBs and between components. In some cases, like this unit, captive crud under PCBs required removal of mainboard and PSU. Fortunately with this unit that was pretty easy; the naughty bits are almost all on the mainboard, and just a couple ribbon cables to PSU and monitor. This before & after reflects a fair bit more time than is apparent.

   

One of the big differences between this scope and my 54645A (on the left) is the frontend. The BNC jacks are actually a integral part of those two chromed pot-metal castings. They are held in place by hooks at the back into the PCB; once you remove the nut on the CAL output and screws in the accessory module port & PCB (and the two in those chromed castings),  you then lift the back of the mainboard and slide everything back until the BNCs clear the front of the metal chassis.

Then you can lift the BNC castings up and they unhook from the PCB in the back. Contact from the core of the BNC to the mainboard is made against a V-shaped bit of gold-plated spring brass. I had taken pics of these details, but evidently the eevBlog wandering singularity followed me home; I have several damaged files on my camera card now and presume those are among them.




Here you can see me cleaning the inside of the BNC jacks with a flattened Q-tip dipped in alcohol to get between the center and shell of the BNC.


   

Next came repairing the control panel & encoder PCB; like my 54645A after the Bumblebutt incident, this corner of the PCB was cracked resulting in damaged traces and non-working buttons. Carefully scraping the solder mask away, I then tin the surface of the traces before soldering down copper wire as reinforcement.

Due to the close proximity to active contacts on the keypad, I used individual strands from old cat5 cable  approx 0.2mm dia. This is all that's needed to effect a reliable long-lasting repair. Wider traces may get more than one strand in parallel if feasible.

After all the soldering is done, I then clean the PCB with toothbrush and IPA, then apply hot air to ensure it is completely dry. Then I reinforce the crack in the PCB with a thin line of CA, followed immediately with a dab of CA accelerant. If done correctly, the accelerant makes the CA run thinner than water before it cures... you will see the CA weep through on the other side of the crack. 

I then let it all sit for about 10 minutes to dry and cure; then I clean both sides of the PCB again with Q-tips & IPA, before applying a layer of clear nail-polish as sealer.




Next came fixing the loose outer film on the bezel; once I'd scrubbed everything with IPA to make it presentable, I masked off everything around the CRT bezel and outer edges. Then, I carefully lifted the clear outer film and sprayed 3M Clear Hobby Adhesive on both the back of the film and the front of the panel.

After that, I laid a gallon Ziploc bag down over all of it and used my fingers to press the film down into place starting from the part that was still attached and working outward towards the end of the panel. This tactic ensured that the traces of print on the back of the film aligned perfectly with the print still on the front panel. Then I left it to cure overnight; next day I removed masking and clean up with IPA on a rag.

   

During all this work I was printing up replacement knobs for the missing ones. The smaller knob was found on ThingiVerse, and fortunately the creator included his .F3D file, so it was a relatively simple matter to rescale in the X & Z axes (X & Y on your printer) to make a 17mm dia version of the smaller knob. I'll post both to the 3DP knobs thread later.



And the money shot; which of course all y'alls have already seen. Not perfect, but definitely a lot better than the "as-delivered" pic.

mnem
 

[bd139]

We're all fucked at some point. It's just about controlling how soon as best as possible.

Just found out how much Russia fucked my pension today. 3 years of contributions down the shitter. I've just shit canned all contributions to it in the short term and will spend it on beer, floozies, scopes and power supplies 

Not just Russia, it is the omnicrisis.

At this RPI, my pension will halve in value in about 7 years. And I can't do anything to improve that.

I should become a millionaire next week. Unfortunately since I have a daughter, that will only last a month or so.

Omnicrisis is a good way of putting it.

Similar situation. Alas it's mostly in liquid cash at the moment as it's being consolidated and moved around so when it's in the bank account it's just burning. It worked out better to pay a year's rent in the new place up front than pay monthly. I'll buy something else next year and move into that and ride it for as long as possible.

This week about half my cash is earning 7%. Next week I'll have more cash, but it won't be earning anything like that.

Next year house prices won't go up, and are likely to fall. Doesn't bother me, but sproglet is being forced to buy one within 3 months (no fault eviction, self-employed, with a dog).

Depends where and what. The market I'm entering, in London, has competition from people downsizing from oversized houses into reasonable ones unfortunately. The prices won't be going down here.

Locations and timing are everything, of course. But the concept of downsizing from an oversized house in London eludes me. Getting out of a flat seems bleeding obvious, especially if it is high rise.

But won't you be able to move in with your next redhead?

The reason people are downsizing is from what I am seeing is that either their kids have left home, they got stuck at home during Covid with someone they hated and have got divorced and need to split it 50/50, they got laid off from work thanks to covid and have to take a lesser salary or want to free up some cash because their other investment returns are tanking.

There are a lot of very very nice flats here. I'm considering buying one. Nice view ...

[Cubdriver]

Poor counters can’t get no love…. 


-Pat

Just curious : the two instruments at the bottom... they have  a mix of period knobs, and next generation plastic knobs found on later HP TE... did HP create these hybrid monsters, they came from the factory like that  ?:!  or did you just put these knobs yourself to replace missing ones ? Not judging... just curious to learn... if HP did that themselves, I wanna know...

Funny that in all the years I've had them I never noticed that.  Yes, they did come like that, with the larger, better 60s style knobs for the function and range switches, and the blech (IMO) 70s style knobs for the input level setting.  So yes, HP did indeed create these hybrid monsters.

-Pat

[Vince]

I don't  understand the comparison between the two ? I mean they are just different things. 4000 series has a voltage range of 3 to 15V. 74HC / HCT if I believe the datasheet I just pulled, is 2 to 6V.
I understand your points, taken...but if I need to supply the logic for whatever reason above 6V, I am screwed with 74-anything.
Or if the circuit doesn't have stable supply voltage and the logic cheap needs to be able to operate with a changing supply voltage ?! 

It's probably cheaper now to just chuck a 78L05 in the circuit and be done. That will handle both problems for pocket change.

Don't be so .. practical . That's not fun. 

Come to think of it, I have one practical / real world example where 4000 chips were favored instead of 74. Had to fix the electronics in a consumer Expresso machine, and let me tell you the cost cutting on the board was such that using a 74XX + a 7805 chip (and caps to go with it) just was NOT an option ! 

Here, found a pic of the board I took back then.  It's from a " MAGIMIX  M150 " coffee machine.

The board takes mains in.

Power supply : single diode / half wave rectification, then one tiny Zener with a beefy series resistor, and one small smoothing cap. Done !

Logic : two 4000 chips.

One is a counter, its clock input is driven by the mains !!!  There is only one high value resistor to limit the current, and I guess they make use of the internal input protection diode to rectify the mains 

Then the second chip drives a Thyristor that powers the water pump of the coffee machine.  The Thyristor keeps blowing, replaced it once, pump ran for a few seconds then it blew again... thinking the pump might be leaking internally, water getting into the motor and shorting it, overloading the Thryristor ?! My best guess  anyway 

[dl6lr]

Just wanted to say hello again.

Back from holiday. I had a ride on my bicycle from Magdeburg to Hörstel along the Mittellandkanal here in Germany. All together about 460km. On my way back I stopped in Osnabrück and found a "Yes, it's bicycle repair man" with a bicycle washing machine. So I had my wifes and my bike washed by a smart young man, see attached photo. Very convenient! The guy asked me because of all the dust: Have you been in the Sahara? 

No TEA but I avoided some WEA (washing equipment acquisition), as the washing machine flicked the RCD before holiday and refused to turn the motor afterwards. So I disassembled and cleaned the motor and found the brushes to be still in good condition (but a lot of dust around) and it turned fine on the variac. So I concluded to search for the issue in the electronics. I found one TRIAC to be suspicious and ordered a replacement. Changed yesterday after returning home and now the machine is working fine again.

[tautech]

I don't  understand the comparison between the two ? I mean they are just different things. 4000 series has a voltage range of 3 to 15V. 74HC / HCT if I believe the datasheet I just pulled, is 2 to 6V.
I understand your points, taken...but if I need to supply the logic for whatever reason above 6V, I am screwed with 74-anything.
Or if the circuit doesn't have stable supply voltage and the logic cheap needs to be able to operate with a changing supply voltage ?! 

It's probably cheaper now to just chuck a 78L05 in the circuit and be done. That will handle both problems for pocket change.

Yes again not saying 4000  is better, just saying it's different and it thus allows potentially to do stuff you can't do with a 74 (alone).
It's up to the designer and bean counters to decide if it makes more sense for a particular project to go one route or the other. But at least 4000 series gives you options, and options are always good... 

These days we have more options like lower threshold MOSFET gates so we don't need to use level convertors so much and in this realm is where 4000 were so beneficial.
Lots of fun playing with glue logic that most can't be bothered with these days and instead just use a micro which is fine if you can program. 

[Vince]

Just wanted to say hello again.

Back from holiday. I had a ride on my bicycle from Magdeburg to Hörstel along the Mittellandkanal here in Germany. All together about 460km. On my way back I stopped in Osnabrück and found a "Yes, it's bicycle repair man" with a bicycle washing machine. So I had my wifes and my bike washed by a smart young man, see attached photo. Very convenient! The guy asked me because of all the dust: Have you been in the Sahara? 

No TEA but I avoided some WEA (washing equipment acquisition), as the washing machine flicked the RCD before holiday and refused to turn the motor afterwards. So I disassembled and cleaned the motor and found the brushes to be still in good condition (but a lot of dust around) and it turned fine on the variac. So I concluded to search for the issue in the electronics. I found one TRIAC to be suspicious and ordered a replacement. Changed yesterday after returning home and now the machine is working fine again.

A washing machine for bicycles ?! 

Didn't even know such a thing even existed, thanks... you learn a little something every day they say...

[Vince]

The reason people are downsizing is from what I am seeing is that either their kids have left home, they got stuck at home during Covid with someone they hated and have got divorced and need to split it 50/50, they got laid off from work thanks to covid and have to take a lesser salary or want to free up some cash because their other investment returns are tanking.

There are a lot of very very nice flats here. I'm considering buying one. Nice view ...

Looks nice for a lab, but what does it have for a living room and bedrooms ?! 

[bd139]

The reason people are downsizing is from what I am seeing is that either their kids have left home, they got stuck at home during Covid with someone they hated and have got divorced and need to split it 50/50, they got laid off from work thanks to covid and have to take a lesser salary or want to free up some cash because their other investment returns are tanking.

There are a lot of very very nice flats here. I'm considering buying one. Nice view ...

Looks nice for a lab, but what does it have for a living room and bedrooms ?! 

You're doing it wrong:

Living room = lab with sofa in it.
Bedroom = storage area with bed in it.

[tggzzz]

The reason people are downsizing is from what I am seeing is that either their kids have left home, they got stuck at home during Covid with someone they hated and have got divorced and need to split it 50/50, they got laid off from work thanks to covid and have to take a lesser salary or want to free up some cash because their other investment returns are tanking.

There are a lot of very very nice flats here. I'm considering buying one. Nice view ...

So the usual reasons, but people are forced to sell their current house low and buy a new house high. Oops.

These are my views..

[Vince]

Personally the old CMOS 4000 series are DEAD other than the CD4007 which is still quite useful as it's basically uncommitted MOSFET inverter which can be snuck into various analogue circuits.

The 4000 series have one nice characteristic: operation at IIRC 3V to 15V

Back in the late 70s I used some to build a fllter with a Q of 4000 using 10% capacitors, capable of measuring 1pW using  bog-standard LF351 op amps, and a dynamic range of 180dB (90dB optical).

Yes and no. A lot of the characteristics were wide across the voltage range which was a big problem. A fine example I saw was a car alarm built around a couple of CD4001's. It only worked properly if the battery was above about 11.5 volts. So if you didn't use your car for a few weeks then it'd go off all by itself 

You are a bad mouth, you simply failed to appreciate the rich feature set of this alarm. It has an option to alarm you when your battery is running low, which is useful in itself !
Especially on modern cars I hear, where a low battery can upset lots of ECU all around the car and they fill the main ECU with thousands of nonsensical errors that don't even exist 

[Vince]

The reason people are downsizing is from what I am seeing is that either their kids have left home, they got stuck at home during Covid with someone they hated and have got divorced and need to split it 50/50, they got laid off from work thanks to covid and have to take a lesser salary or want to free up some cash because their other investment returns are tanking.

There are a lot of very very nice flats here. I'm considering buying one. Nice view ...

Looks nice for a lab, but what does it have for a living room and bedrooms ?! 

You're doing it wrong:

Living room = lab with sofa in it.
Bedroom = storage area with bed in it.

Uh ?! Have you been spying through my windows or what, how do you know how my house is inside ?! 


 

[Vince]

The reason people are downsizing is from what I am seeing is that either their kids have left home, they got stuck at home during Covid with someone they hated and have got divorced and need to split it 50/50, they got laid off from work thanks to covid and have to take a lesser salary or want to free up some cash because their other investment returns are tanking.

There are a lot of very very nice flats here. I'm considering buying one. Nice view ...

So the usual reasons, but people are forced to sell their current house low and buy a new house high. Oops.

These are my views..

Gee you are getting real good at Photoshop, the lighting and blue skies look so real !   

[tggzzz]

The reason people are downsizing is from what I am seeing is that either their kids have left home, they got stuck at home during Covid with someone they hated and have got divorced and need to split it 50/50, they got laid off from work thanks to covid and have to take a lesser salary or want to free up some cash because their other investment returns are tanking.

There are a lot of very very nice flats here. I'm considering buying one. Nice view ...

So the usual reasons, but people are forced to sell their current house low and buy a new house high. Oops.

These are my views..

Gee you are getting real good at Photoshop, the lighting and blue skies look so real !   

I'm not that clever. The estate agents selling my parent's house were that clever!

EDIT: added this picture taken when there was uniform gray stratus cloud...

[Vince]

So, for lack of better things that I want to do... I'm going to chronicle this little adventure in TEA...


mnem
 

Wow with all that work done to it, I guess you now know what to do with that scope ! You won't sell it, would not make enough money to be worth your work.
You won't even use it for parts... you will just keep it in working state as a little brother to keep your Megazoom company.

But these purple knobs still bugs me ! 

I understand it's just the camera and they are grey in the flesh but... camera have better eyes than we do, sometimes... if it says it's purple, it might well be !
Your brain just can't perceive it that's all... I would paint them grey if just so they actually look grey next time you take pictures of the scope ! 
With all the work you have done to it, I don't think a bit of painting would be enough to scare you....

[mansaxel]

5440 5B40 update:

U165 is toast.  The trigger signal arrives, in-spec, to it, and does not depart. There's no blown tant on its supply; it has just below 5V on the supply pin, and it's not noisy. It does also draw some power.

Parts list sez:

Code: [Select]

U165     155-0109-00    B010100  B021739    MICROCIRCUIT,LI:MONOLITHIC,TRIG       80009   155-0109-00
So, a quick Ebay glance gives that it is not Unobtanium; there are a couple sellers on the bay who want around 25 money for one, plus transatlantic shipping. Stiff prices, them.  Does anyone here sit on a few?

[mnementh]

   So, for lack of better things that I want to do... I'm going to chronicle this little adventure in TEA...

Wow with all that work done to it, I guess you now know what to do with that scope ! You won't sell it, would not make enough money to be worth your work.   You won't even use it for parts... you will just keep it in working state as a little brother to keep your Megazoom company.

But these purple knobs still bugs me !  I understand it's just the camera and they are grey in the flesh but... camera have better eyes than we do, sometimes... if it says it's purple, it might well be ! Your brain just can't perceive it that's all... I would paint them grey if just so they actually look grey next time you take pictures of the scope !  With all the work you have done to it, I don't think a bit of painting would be enough to scare you....

Can't see 'em with it parked under my workbench; doesn't bother me a bit.    Especially as I'm now upstairs in the living room with a plate of hot apple pie brought home by my wife. Fuck those knobs. 

mnem
and fuck those carbs, too. Yumm.