Test Equipment Anonymous (TEA) group therapy thread

[bd139]

Indeed  . Less smoke and no fines today though.

Have decided to dig out the curve tracer again as my "downtime" project. Have on and off designed a new high voltage amplifier for it. Hopefully this one won't be quite as explodey.

[BU508A]

Well fuck today as well. Another pile of immense pile of excrement to deal with.

Karma-wise I reckon I am owed a 34401A now at a £50 price point

Oh dear, another calamitous day then? I rather like the sound of a 34401A for around £50 though, tell where?

How about to introduce bd139 to this lady?

https://en.wikipedia.org/wiki/Calamity_Jane

 

[25 CPS]

Here are some recent scores.  First up is a Sperry-Remington nixie calculator.  It only performs four arithmetic functions. It has no way of directly entering a negative number.  It’s amazing how expensive such a basic machine like this would’ve been when it was new.  But the display is gorgeous.



Next up is a pretty much new in box Triplett multimeter that’s still in its box after I put it back in when I looked at it.



Moving along is an HP 3455A.



And I was able to jump outside in time to catch the Lancaster doing a Remembrance Day flyby just after 11:00 this morning.



Full zoom on the iPhone is still pretty wide so it looks a lot further away in the picture than it was in person.  Up close, flying by slowly at low altitude, that airplane is an impressive sight and sound.  My grandfather used to fly those in the RAF.

[Specmaster]

While I was browsing my local Lidl the other day I spotted a vice and discounted it because I thought it was one of those suction mount ones that don't quite work on a wooden surface  I already have one of those useless bastards. Anyway, son picked it and said it wasn't one of them but a clamp-on one, so I had a closer look and purchased it for a cool £7.95.

It has a 3" wide jaw and open to a tad under 3", has a ball joint so the head can be moved to suit the job in hand and comes with an attachment which fits in place of the vice on the clamp and will allow a normal power drill to clamped just behind the chuck thus allowing the grindstone etc to be used like a bench grinder etc, very useful tool. Just now looking on Amazon, I notice that there are many sellers of what purports to be the same thing at a quick glance, priced from around £18 to £36 but without the power tool attachment and with max opening of the jaw to 2", the rest is identical, then I spot the power tool attachment, supplied with the bench clamp, identical to the Lidl clamp and the price was £18 for that on its own. I think I got a good result there then, well worth £7.95 I paid for it

[bd139]

Edit to add: That actually looks pretty good for £7.95. Might grab one myself. I need something to hold small PCB assemblies while probing / testing etc. And quite frankly the Panavise is too expensive.

Something random - TDS400 hacking article which was an interesting read:

https://tomverbeure.github.io/2020/07/11/Option-Hacking-the-Tektronix-TDS-420A.html

[mnementh]

Indeed  . Less smoke and no fines today though.

Have decided to dig out the curve tracer again as my "downtime" project. Have on and off designed a new high voltage amplifier for it. Hopefully this one won't be quite as explodey.

Is there a good reason not to use (perhaps even plagiarize) one of the many inexpensive boost converter modules out there and just get on with your life?

https://www.ebay.com/sch/i.html?_from=R40&_sacat=0&LH_TitleDesc=0&_nkw=200v+boost+converter

Seems to me your time is much better spent on the core design rather than reinventing the wheel... 

mnem
 

[Specmaster]

Edit to add: That actually looks pretty good for £7.95. Might grab one myself. I need something to hold small PCB assemblies while probing / testing etc. And quite frankly the Panavise is too expensive.

Something random - TDS400 hacking article which was an interesting read:

https://tomverbeure.github.io/2020/07/11/Option-Hacking-the-Tektronix-TDS-420A.html

You have a TDS400 don't you? Are you going to hack it then?

[Robert763]

Just wondering... I always shrugged off Farnell powersupplies as rebrands/housebrand. Is there more to it? They seem ubiquitous in the UK... Actually have one on the bench right now...

As others hav said Farnell were big on PSUs not just bench ones.
Not Just PSUs either, They made a whole range of bench TE from multimeters throught to 'scopes and RF TE.
 lot of it looks a bit "made from standard parts", but it works OK.

[Cerebus]

I used to live where I've put the orange star, a little bit over \$\frac{1}{2}\$ a mile from the end of the runway at RAF Northolt. Iused to get to see the underside of all sorts of interesting things on days when there were ceremonial flights. The most impressive was a Lancaster taking off from Northolt being joined by a escort of two Spitfires - loud does not do justice to what was passing by at less than 150 feet.

[Specmaster]

When I was at Lidl, I also picked up one of these 450mm long magnetic toolbars for £2.99, just haven't got round to fixing it to the wall yet 

[med6753]

Before. 




After.  Circuit is an LM317T so I can vary the voltage and the speed for best cooling vs noise. The new fan is by no means silent but a hell of a lot quieter then original. I think if I find some sort of foam filter it will be even quieter. And even at a slow speed this fan pulls air much stronger than the original.

Going to install it and power up the Type 310A and check the results.

[bd139]

Indeed  . Less smoke and no fines today though.

Have decided to dig out the curve tracer again as my "downtime" project. Have on and off designed a new high voltage amplifier for it. Hopefully this one won't be quite as explodey.

Is there a good reason not to use (perhaps even plagiarize) one of the many inexpensive boost converter modules out there and just get on with your life?

https://www.ebay.com/sch/i.html?_from=R40&_sacat=0&LH_TitleDesc=0&_nkw=200v+boost+converter

Seems to me your time is much better spent on the core design rather than reinventing the wheel... 

mnem
 

It's far more complicated problem than it sounds. I need a variable 0-1000V linear sweep triangle generator that'll run between 30 and 100Hz which will not burst into oscillation when various capacitive, inductive and resistive loads are attached. I have reduced the initial build requirements to 200 volts which should be enough to test avalanche breakdown and signal diode breakdown etc.

Edit to add: That actually looks pretty good for £7.95. Might grab one myself. I need something to hold small PCB assemblies while probing / testing etc. And quite frankly the Panavise is too expensive.

Something random - TDS400 hacking article which was an interesting read:

https://tomverbeure.github.io/2020/07/11/Option-Hacking-the-Tektronix-TDS-420A.html

You have a TDS400 don't you? Are you going to hack it then?

No I don't own one and am not going to hack one. It was an interesting reverse engineering session. What you learn from those can be applied to other things

[mnementh]

Two things - one, the British police see the public through a windscreen nowadays, the days of the "bobby on the beat" are long gone.

There still are a lot more cops over there walking the beat than over here. Enough that you see them in people's actual photos. It's been decades since that was true on this side of the pond.

Those are really few and far between. The only place you'll see patrols on foot are pedestrianised areas of town centres and when they've been tasked to special events, from fairs (where it's as much a 'show some faces' exercise as it is actual policing) to events that might have some public order element, but are low key enough not to turn out the heavy mob. You won't see them literally 'walking the beat' the way you did years ago. I haven't see a patrol walk down my street in 30 or 40 years or more, only turning up in a response car. One clue is in the day's assigned duty, the default if you weren't doing anything specific like 'enquiries', 'custody' or other assigned duty was to be assigned to 'patrol' for the day, now the default is to be on 'response'.

Many years ago I used to know the local beat bobby to nod to in the street like I still do the postman, nowadays the local 'Safer Neighbourhood Team' is just a twitter handle.

Or worse, it's some dingle nosy-neighbor with a cellphone on citizen patrol. This is precisely what's wrong.

mnem
 

[bd139]

Before. 




After.  Circuit is an LM317T so I can vary the voltage and the speed for best cooling vs noise. The new fan is by no means silent but a hell of a lot quieter then original. I think if I find some sort of foam filter it will be even quieter. And even at a slow speed this fan pulls air much stronger than the original.

Going to install it and power up the Type 310A and check the results.

Nice job. Really like that 

[tggzzz]

While I was browsing my local Lidl the other day I spotted a vice and discounted it because I thought it was one of those suction mount ones that don't quite work on a wooden surface  I already have one of those useless bastards. Anyway, son picked it and said it wasn't one of them but a clamp-on one, so I had a closer look and purchased it for a cool £7.95.

It has a 3" wide jaw and open to a tad under 3", has a ball joint so the head can be moved to suit the job in hand and comes with an attachment which fits in place of the vice on the clamp and will allow a normal power drill to clamped just behind the chuck thus allowing the grindstone etc to be used like a bench grinder etc, very useful tool. Just now looking on Amazon, I notice that there are many sellers of what purports to be the same thing at a quick glance, priced from around £18 to £36 but without the power tool attachment and with max opening of the jaw to 2", the rest is identical, then I spot the power tool attachment, supplied with the bench clamp, identical to the Lidl clamp and the price was £18 for that on its own. I think I got a good result there then, well worth £7.95 I paid for it

I've got something like that, albeit without the drill clamp. I find it useful on occasions, but not every week. Worth £8+

[mnementh]

Indeed  . Less smoke and no fines today though.

Have decided to dig out the curve tracer again as my "downtime" project. Have on and off designed a new high voltage amplifier for it. Hopefully this one won't be quite as explodey.

Is there a good reason not to use (perhaps even plagiarize) one of the many inexpensive boost converter modules out there and just get on with your life?

https://www.ebay.com/sch/i.html?_from=R40&_sacat=0&LH_TitleDesc=0&_nkw=200v+boost+converter

Seems to me your time is much better spent on the core design rather than reinventing the wheel... 

mnem
 

It's far more complicated problem than it sounds. I need a variable 0-1000V linear sweep triangle generator that'll run between 30 and 100Hz which will not burst into oscillation when various capacitive, inductive and resistive loads are attached. I have reduced the initial build requirements to 200 volts which should be enough to test avalanche breakdown and signal diode breakdown etc.

Edit to add: That actually looks pretty good for £7.95. Might grab one myself. I need something to hold small PCB assemblies while probing / testing etc. And quite frankly the Panavise is too expensive.

Something random - TDS400 hacking article which was an interesting read:

https://tomverbeure.github.io/2020/07/11/Option-Hacking-the-Tektronix-TDS-420A.html

You have a TDS400 don't you? Are you going to hack it then?

No I don't own one and am not going to hack one. It was an interesting reverse engineering session. What you learn from those can be applied to other things

Ahhh... I thought your problems were caused by poor HV voltage/current regulation, not the function gen itself. Or is it both...?

Agreed on the reverse-engineering stuph. That kind of shit is why I still tune into Hackaday from time to time, even tho the SNR has gone to shit with the invasion of the  twitts.

mnem
 

[Specmaster]

I used to live where I've put the orange star, a little bit over \$\frac{1}{2}\$ a mile from the end of the runway at RAF Northolt. Iused to get to see the underside of all sorts of interesting things on days when there were ceremonial flights. The most impressive was a Lancaster taking off from Northolt being joined by a escort of two Spitfires - loud does not do justice to what was passing by at less than 150 feet.

Nice, but if you want loud, you want to be hear a F15 taking off from RAF Lakenheath, from 760 yards away, thats the distance from the viewing bay to the piano keys on the runway, they make the car vibrate along with your stomach and set off car alarms and leave your ears ringing

This video does not do it justice 

[tggzzz]

I used to live where I've put the orange star, a little bit over \$\frac{1}{2}\$ a mile from the end of the runway at RAF Northolt. Iused to get to see the underside of all sorts of interesting things on days when there were ceremonial flights.

I live at 90 degrees to the local big runway, which wasn't an accident. There's no way I would want to live in one of the villages 1km-1mile from the runway end.

Hence the most exciting things I see are balloons and smiley faces (qv), and this:

The most impressive was a Lancaster taking off from Northolt being joined by a escort of two Spitfires - loud does not do justice to what was passing by at less than 150 feet.

Try a Vulcan in a climb

[mnementh]

Before.     

After.  Circuit is an LM317T so I can vary the voltage and the speed for best cooling vs noise. The new fan is by no means silent but a hell of a lot quieter then original. I think if I find some sort of foam filter it will be even quieter. And even at a slow speed this fan pulls air much stronger than the original.

Going to install it and power up the Type 310A and check the results.    

Nice & simple. I like it. Be careful trying to control speed on these with voltage; go too low and they can smoke themselves. There's a reason we have the 4-wire ones with PWM speed control in our computers now. Keep that 12v one above 6-7 volts and you should be okay tho. 

mnem
 

[med6753]

Before. 




After.  Circuit is an LM317T so I can vary the voltage and the speed for best cooling vs noise. The new fan is by no means silent but a hell of a lot quieter then original. I think if I find some sort of foam filter it will be even quieter. And even at a slow speed this fan pulls air much stronger than the original.

Going to install it and power up the Type 310A and check the results.

Nice job. Really like that 

And I found the perfect filter element. The black foam used in window A/C units. Can be cut to size. Ordered a sheet from Amazon. 

[mnementh]

Don't forget a grill over the front of the fan, or scrounge up some hardware cloth or plastic mesh to support the foam.

If you don't, the fan will suck up the foam & shred it or jam up & smoke itself in short order. Ask me how I know. 

mnem
The downside of Empirical Engineering...

[McBryce]

What can Brown do for you?

Germans may have a different answer to this question

Have been to the Gould Advance site in Bishops Stortford a few times in a previous role and it is sad to see some great names being swallowed into a bigger group etc. It is hard these days to know, who owns who.

This is the former site in Bishops Stortford where so many power supplies came from.

I lived in Bishops Stortford in the late 90's, wasn't aware that I was living close to Gould at the time though

McBryce.

[bd139]

I lived in Bishops Stortford in the late 90's, wasn't aware that I was living close to Gould at the time though

You poor fucker. Thorley represent!

[Specmaster]

I used to live where I've put the orange star, a little bit over \$\frac{1}{2}\$ a mile from the end of the runway at RAF Northolt. Iused to get to see the underside of all sorts of interesting things on days when there were ceremonial flights.

I live at 90 degrees to the local big runway, which wasn't an accident. There's no way I would want to live in one of the villages 1km-1mile from the runway end.

Hence the most exciting things I see are balloons and smiley faces (qv), and this:

The most impressive was a Lancaster taking off from Northolt being joined by a escort of two Spitfires - loud does not do justice to what was passing by at less than 150 feet.

Try a Vulcan in a climb

Nah, honestly, not a patch on a F15 with full after burners on, but the Vulcan was loud I grant you, in fact it was perhaps my all-time favourite aircraft with many memories of how the RAF used to chuck it about the sky in a fashion the Vulcan trust just never did and were in fact forbidden from doing by the CAA.

[McBryce]

I lived in Bishops Stortford in the late 90's, wasn't aware that I was living close to Gould at the time though

You poor fucker. Thorley represent!

I was working for Ford in Dunton at the time. Moved to Hornchurch after a few months when I realised that BS wasn't where I wanted to be.

McBryce.