Test Equipment Anonymous (TEA) group therapy thread

[med6753]

The voice is a little in need of Beer and food after a day of making sawdust 

Cheap and Cheerful Poscast Mic arrived as a quick test one on the dongle and one on the B450/AMD motherboard jack. Works fine on Discord with buckets of gain and a quick and dirty clean test with no processing or noise cancelling via windoze recorder. Dongle was a no fuss plugin too.

Maybe the Adapter by a bit too 

Well worth the few pesos eBay auction: #324030959176 and I will have a little play with it's guts if I get a chance.

Sounds great!  Absolutely no doubt where you hang out, that Aussie accent comes thru loud and clear. 

[VK5RC]

For me it was the Dick Smith ESR meter.  It was my first electronic kit that actually yielded a usable tool; while I'd built many "Lab kits" and repaired a number of Heath products I never built one.

For the curious, the AADE LCIIB manual is here as a pdf.

mnem
*toddles off to ded*

I have one - really useful, the kit is still available, not cheap though https://www.altronics.com.au/p/k2574-esr-meter-kit/
Rob

[Specmaster]

For me it was the Dick Smith ESR meter.  It was my first electronic kit that actually yielded a usable tool; while I'd built many "Lab kits" and repaired a number of Heath products I never built one.

For the curious, the AADE LCIIB manual is here as a pdf.

mnem
*toddles off to ded*

I have one - really useful, the kit is still available, not cheap though https://www.altronics.com.au/p/k2574-esr-meter-kit/
Rob

Its still a very basic device so is expensive for what it does. you can get more comprehensive devices on the market, cost less ans just as accurate that will do more as well.

[tggzzz]

I know and like Guildline kit, but this is a Solartron 7075 7.5 digit DVM by any other name.

https://www.ebay.co.uk/itm/Guidline-Guildline-Model-9577-Precision-Digital-Voltmeter/274205230804

Now I know the Panaplex display is delicious, but adding a zero onto the asking price (USD1000) is away with the færies!

[mnementh]

For me it was the Dick Smith ESR meter.  It was my first electronic kit that actually yielded a usable tool; while I'd built many "Lab kits" and repaired a number of Heath products I never built one.

For the curious, the AADE LCIIB manual is here as a pdf.

mnem
*toddles off to ded*

I have one - really useful, the kit is still available, not cheap though https://www.altronics.com.au/p/k2574-esr-meter-kit/
Rob

Its still a very basic device so is expensive for what it does. you can get more comprehensive devices on the market, cost less ans just as accurate that will do more as well.

Yeah... this is true of both tools, I hate to say but it's true. The PEAK/ATLAS ESR70 beats the Smith & Blue meters all hollow, and the DE5000 does everything the AADE LCIIB does and more, with 100x the range.

Still doesn't mean I wouldn't buy again & build both if they came to me at a reasonable price, though. 

mnem
  am I doing STILL up..?!?

[VK5RC]

Time for dwagons to go to bed.  '.... they will sleep all night.....'      Dr Seuss.

[grizewald]

We used to be on the same (commercial) bulletin board, CIX, back in the pre-Internet days - it grew out of a shareware distribution scheme with associated FIDO BBS which eventually morphed into CIX. We both joined it at its inception (about '85 or '86) when it was pretty small and everybody knew everybody else. Used to see him face to face about once a year at the annual barbecue which CIX threw for their customers.

CIX! That takes me back...

I used to be the mod for the 'jokes' conference on CIX (and the hidden 'insensitive' conference). I had to give it up when I moved to Sweden.

[bd139]

For me it was the Dick Smith ESR meter.  It was my first electronic kit that actually yielded a usable tool; while I'd built many "Lab kits" and repaired a number of Heath products I never built one.

For the curious, the AADE LCIIB manual is here as a pdf.

mnem
*toddles off to ded*

I have one - really useful, the kit is still available, not cheap though https://www.altronics.com.au/p/k2574-esr-meter-kit/
Rob

Its still a very basic device so is expensive for what it does. you can get more comprehensive devices on the market, cost less ans just as accurate that will do more as well.

Not quite true in this case.

The test method of the AADE one is much much better for lower value parts (pF / nH). The DER5000 and the Peak units use an impedance bridge whereas the AADE uses an LC oscillator and counter and some clever mathematics which reduce the problem to an accurate reference capacitor and differential measurement of frequency which cancels all the fixture and cable parasitics automatically. Thus the AADE one potentially has a higher resolution and better parasitic immunity and auto nulling than all the other units on low value parts which are present in radios in large quantities.

You can build your own naive one with the instructions here, a frequency counter and a calculator or desktop PC program to crunch the numbers: https://www.robkalmeijer.nl/techniek/electronica/radiotechniek/hambladen/73/1990/09/page48/index.html

[Dek]

It's ALIVE...it's ALIVE

All the caps were OK even the bleeding Tants:palm:
Took out the 7805 reg and put 10v up it and it works Ok, nice steady 5v 
Ah-harrrr, increase that to 10.2 and the 5v output falls over. The raw DC from the rectifier/smoothing cap is also about 10.2.
Bung in a new reg and all is well in the world.
Needs a bit of work on 1 or 2 of the range switches, but looks like it's a goodun saved from the bin.
Now to check the calibration with all my un-calibrated kit

Dek

[Cerebus]

... reduce the problem to an accurate reference capacitor ...

And there's the chicken and egg problem. How do you get an accurate reference capacitor without a decent LCR meter to measure it with? 

[BU508A]

... reduce the problem to an accurate reference capacitor ...

And there's the chicken and egg problem. How do you get an accurate reference capacitor without a decent LCR meter to measure it with? 

How about machining a capacitor in a vacuum with a very precise and well-known geometry? What accuracy can be achieved, when you calculate then the capacity and measure it?

Edit:
Something similiar like this:

[bd139]

Nah. One buys a decent quality silver mica capacitor such as a Cornell CD19FD102FO3F

http://www.farnell.com/datasheets/1731345.pdf

Edit: or slightly cheaper polystyrene film such as LCR FSCEX 1000PF 1% 250V

http://www.farnell.com/datasheets/1786669.pdf

[BU508A]

5900pf / 0.3%  That is nice!

https://www.ebay.com/itm/192893630096

Example:

[bd139]

Now we're talking. Not expensive either! Bigger capacitors relative to the stray board capacitance due to capacitor placement are a winner.

[BU508A]

Out of curiousity I've bought 3 pieces with 0.3%.
Values: 4300pF, 5900pF and 8000pF (0.5% this one)

My DER DE5000 should coming by end of month so I can do some measurements.

[madao]

TDS540 with minor capacitor plague has  a heavy fail: broken  CTL , a IC with  cooler tower is semi-broken. Differntial-ECL output, one of both is open, dead.  But  TDS540 is with this bad U1001(CTL)  useable (but  SPC always failed, because jitter-generator didn't work.)

Good news: i have  spare part of TDS520 (it is build up with  TDS540A acqusisition board,) 

U1001 (CTL) Swapped -> this error  "ctlconfidenceDiag  blabla  = 7" disappears.  Next error is  bad memory in CH2.

Etched thourgh pcb trace: only  3, but i  guess: Bad memorys cause is also etched pcb trace.

[WastelandTek]

Of a more TEAish flavor,  I was lucky enough to acquire one of these recently:

(Attachment Link)

A still-in-the-bag AADE LC meter kit, legendary among ham radio operators of a certain bent, at least in the United States. Another recent arrival is a first generation Norcal 40 kit, also still in its original bag.   

I think I am going to set aside working on test gear for a bit and build me some electronics.  After, of course, I put the dryer back together and figure out exactly where the HVAC guy hid the damper actuator for the second floor heating so I can replace it.

That was a good find. I’ve been after one of those for about 5 years. And typically as is always with stuff on my build list, the dude went SK  . RIP.

Did he? oh noo

I interacted with him just a couple years ago, he was getting a bit grumpy but did help me identify a suitable LCD replacement for my unit.

sorry to hear that

[Cerebus]

There are some who would characterise 0.3% as an approximation rather than a measurement. 

Went and did the back-of-fag-packet calculations for a constructed reference plate capacitor. With a 1mm vacuum/dry air gap you'd need a plate 106.273 659 3 mm square to get a 100 pF capacitor. If you can machine the plates to within 100 um (4 thou for the metrically challenged) and (for simplicity's sake) assume that you could get the gap bang on then you'd be looking at ±0.2% precision for each plate, 0.4% overall (slightly less if you use an RMS calculation which you probably should). If you assume the same absolute tolerance for the gap all bets are off, you're immediately into 10% tolerance territory.

This is really an academic exercise because with such a physically large 100 pF capacitor the stray capacitance and inductance of just connecting it to your circuit would rapidly swamp the innate errors. The innate difficulty of precise capacitance and inductance measurement is why you get volt-nuts and time-nuts but not farad-nuts and henry-nuts, there's not much mileage in boasting about your 3000 ppm accuracy when the others are chasing < 1 ppm. 

[bd139]

That was a good find. I’ve been after one of those for about 5 years. And typically as is always with stuff on my build list, the dude went SK  . RIP.

Did he? oh noo

I interacted with him just a couple years ago, he was getting a bit grumpy but did help me identify a suitable LCD replacement for my unit.

sorry to hear that

Unfortunately so. I think it was 2015. You may have spoken to the due at Morse Express who is indeed one grumpy fucker. I phoned them last year before I bought the K2 to look at grabbing an OHR100A transceiver but got put off pretty quick. Elecraft felt a lot more approachable even if it did cost a kidney.

This is really an academic exercise because with such a physically large 100 pF capacitor the stray capacitance and inductance of just connecting it to your circuit would rapidly swamp the innate errors. The innate difficulty of precise capacitance and inductance measurement is why you get volt-nuts and time-nuts but not farad-nuts and henry-nuts, there's not much mileage in boasting about your 3000 ppm accuracy when the others are chasing < 1 ppm. 

Exactly. 2-5% is mostly fine if you design your RF-ey circuits for worst case parameters or make them tunable. And a 1% capacitor will get you there.

[supperman]

Congrats to you for your new 34460A!
Nice setup!
I like the aluminium profiles, I have rebuilt parts of my bench setup with variants of that, too. Very versatile and handy to plan and built.
Is the electrically adjustable desk capable of moving the rack with all your equipment up without damage?

But there are so many other useful/adorable Test Instruments out there, you've just begun.  Relax and let them get to you. 

Working on cleaning up my bench and surrounding space.
Bought some ESD-SMD-Boxes with spring loaded lid made by Wolfgang Warmbier for that to stop several smd parts laying around and getting lost over time...

*currently listening to my "new" audio CD 'Stairways To Heaven'. Great fun.* 

Seems to work no problem (I think rated for 400lbs). I'm super happy with it.

[WastelandTek]

Pretty sure it was him, probably right around the time he was really sick...

I feel bad for bugging him now, I think I will go measure an inductor...

[BravoV]

Out of curiousity I've bought 3 pieces with 0.3%.
Values: 4300pF, 5900pF and 8000pF (0.5% this one)

My DER DE5000 should coming by end of month so I can do some measurements.

Those Russian mica caps are real deal, bought few of them while ago from Russia seller at eBay, and measured with my Fluke PM6306 LCR meter and Mastech MS5308 (equivalent to your DE5000), all are spot on.

There was a forum member (amspire) measured them with an ESI 701 against Genrad 1409-G Standard Mica, the Russian's mica is better, details -> HERE




Size comparison with a TO220 chip and common Cornell thru hole mica cap.

200nF 0.3% 350V


10nF & 200nF

[BU508A]

Exactly. 2-5% is mostly fine if you design your RF-ey circuits for worst case parameters or make them tunable. And a 1% capacitor will get you there.

And for what use are then the 0.3% capacitors? Cannot imagine, that the Russians made them just for fun.

[tggzzz]

... reduce the problem to an accurate reference capacitor ...

And there's the chicken and egg problem. How do you get an accurate reference capacitor without a decent LCR meter to measure it with? 

Have patience, spend money on fleabay for a reference mica capacitor for a cal lab - preferably with its measured value marked on the side.

My largest is 500nF

[bd139]

That's a pretty big and expensive capacitance for mica that!

Exactly. 2-5% is mostly fine if you design your RF-ey circuits for worst case parameters or make them tunable. And a 1% capacitor will get you there.

And for what use are then the 0.3% capacitors? Cannot imagine, that the Russians made them just for fun.

It's a good question. Near near zero temperature coefficient on the other hand tends to be more important than absolute values.