Test Equipment Anonymous (TEA) group therapy thread

[Vince]

The schematic for the time base and Horizontal amplifier are simple enough, and probably use off the shelf components given the specs of the scope (2MHz...).. so this scope will probably be working again by this evening !!!

If only that were true, it is 10MHz and it is a real pig to work on, so I think it will take a bit of time to get it up and running again.

Oops sorry. Looked again at the manual, my bad.... 2MHz is the B/W of the Horizontal amplifier 

Vertical B/W is 10 MHz indeed...

Good luck with the repair, take piccies for us please.. will also help you putting all the bits back together again and resolder alll the pesky wires where they need to go ! 

[Ice-Tea]

Ordering from the UK continues to be a shitshow. Ordered some 30dBm attenuators, never arrived. Seller refunded but it's still a mess...

[Martin Miranda]

i hope this still works. cleaned all the crusty foam.
i have a 500Mhz hp infinium and i'll need to build a power supply for this. 

[Vince]

Vref : end of experiment, need to reclaim the bench space, life goes on...

Been running for 34 Hours now. The DMM still won't budge a iota. Still stuck on 2.5015 V. Not one single digit of change in 34 Hours... ie. less than 100uV.

The chances that both the DMM an Vref drifted in the same direction, by exactly the same amount, at exactly the same time / rate, over the course of 34 hours ... is of course technically possible... just not very likely...

So until I can afford a better meter to recheck this Ref, I will declare both my DMM and Vref quite good indeed.

Plenty good enough to check a 9V battery or power rails when fixing stuff !   

[med6753]

Vref : end of experiment, need to reclaim the bench space, life goes on...

Been running for 34 Hours now. The DMM still won't budge a iota. Still stuck on 2.5015 V. Not one single digit of change in 34 Hours... ie. les than 100uV.

The chances that both the DMM an Vref drifted in the same direction, by exactly the same amount, at exactlty the same time / rate ... is of course technically possible... just not very likely...

So until I can afford a better meter to recheck this Ref, I will declare both my DMM and Vref quite good indeed.

Plenty good enough to check a 9V battery or power rails when fixing stuff !   

As Specmaster has stated several times and I'm inclined to agree for 99% of troubleshooting anything greater than 3.5 digits is overkill.

So sez one who has a 6.5 digit hp 3456A and Fluke 8505A at his disposal. 

[BU508A]

Vref : end of experiment, need to reclaim the bench space, life goes on...

Been running for 34 Hours now. The DMM still won't budge a iota. Still stuck on 2.5015 V. Not one single digit of change in 34 Hours... ie. les than 100uV.

The chances that both the DMM an Vref drifted in the same direction, by exactly the same amount, at exactlty the same time / rate ... is of course technically possible... just not very likely...

So until I can afford a better meter to recheck this Ref, I will declare both my DMM and Vref quite good indeed.

Plenty good enough to check a 9V battery or power rails when fixing stuff !   

As Specmaster has stated several times and I'm inclined to agree for 99% of troubleshooting anything greater than 3.5 digits is overkill.

So sez one who has a 6.5 digit hp 3456A and Fluke 8505A at his disposal. 

It is all about to impress Lady Cop, because 6.5 digits are much longer than 3.5. 

[tggzzz]

There is not a lot of info on the web about this beast and the PCB's are a pig to extract and I don't think will impossible to power it up out of its case because of the way it is constructed internally with daughter boards plugged in all over the place with random flying leads everywhere that need to be unsoldered 

Powering up is easy; just use croc clips on the battery wires.

Separating the PCBs does look like a real pig, since they are soldered together at right angles

[tggzzz]

Ordering from the UK continues to be a shitshow. Ordered some 30dBm attenuators, never arrived. Seller refunded but it's still a mess...

How were they sent; that may make a significant difference.

[med6753]

Vref : end of experiment, need to reclaim the bench space, life goes on...

Been running for 34 Hours now. The DMM still won't budge a iota. Still stuck on 2.5015 V. Not one single digit of change in 34 Hours... ie. les than 100uV.

The chances that both the DMM an Vref drifted in the same direction, by exactly the same amount, at exactlty the same time / rate ... is of course technically possible... just not very likely...

So until I can afford a better meter to recheck this Ref, I will declare both my DMM and Vref quite good indeed.

Plenty good enough to check a 9V battery or power rails when fixing stuff !   

As Specmaster has stated several times and I'm inclined to agree for 99% of troubleshooting anything greater than 3.5 digits is overkill.

So sez one who has a 6.5 digit hp 3456A and Fluke 8505A at his disposal. 

It is all about to impress Lady Cop, because 6.5 digits are much longer than 3.5. 

Well sometimes for that 1% only the big guns will do. 

[Vince]

Vref : end of experiment, need to reclaim the bench space, life goes on...

Been running for 34 Hours now. The DMM still won't budge a iota. Still stuck on 2.5015 V. Not one single digit of change in 34 Hours... ie. les than 100uV.

The chances that both the DMM an Vref drifted in the same direction, by exactly the same amount, at exactlty the same time / rate ... is of course technically possible... just not very likely...

So until I can afford a better meter to recheck this Ref, I will declare both my DMM and Vref quite good indeed.

Plenty good enough to check a 9V battery or power rails when fixing stuff !   

As Specmaster has stated several times and I'm inclined to agree for 99% of troubleshooting anything greater than 3.5 digits is overkill.

So sez one who has a 6.5 digit hp 3456A and Fluke 8505A at his disposal. 

Indeed.  That's why my first DMM, which I bought brand new 25 years ago, a Fluke 11, is still my daily driver and the only one that sits permanently on the bench and goes in the toolbox when I go out or work on the car.... because despite it's 4000 count display and atrocious accuracy, 0.9% accuracy (though I measured it to be much better than this), is plenty good enough for general work, maintenance, repair, debugging during development of a project. It's slim, compact, rugged, easy to operate one handed, fat contrasting digits that are easy to read, good continuity test (fast, sensitive and latched), a stable tilting bale... and it has battle scars and patina... so I am not too worried about it, like I would be with a NIB rare and expensive MX56/C for example, which is also very bulky, unstable tilting bale, scratchy continuity test, needs to hands to rotate the main switch because of that. So I take it out of its drawer only when I need the extra performance or features, or if I just want to enjoy its pretty face and platy with it, of course 

[tggzzz]

Vref : end of experiment, need to reclaim the bench space, life goes on...

Been running for 34 Hours now. The DMM still won't budge a iota. Still stuck on 2.5015 V. Not one single digit of change in 34 Hours... ie. les than 100uV.

The chances that both the DMM an Vref drifted in the same direction, by exactly the same amount, at exactlty the same time / rate ... is of course technically possible... just not very likely...

So until I can afford a better meter to recheck this Ref, I will declare both my DMM and Vref quite good indeed.

Plenty good enough to check a 9V battery or power rails when fixing stuff !   

As Specmaster has stated several times and I'm inclined to agree for 99% of troubleshooting anything greater than 3.5 digits is overkill.

So sez one who has a 6.5 digit hp 3456A and Fluke 8505A at his disposal. 

Agreed, but more digits can be useful when making fine adjustments or measuring small changes such as drift.

Don't forget the allure of different display technologies, e.g. dekatrons, nixie, panaplex, HP's "dotted digits", etc. Numitrons have their charm too.

[ch_scr]

Today I set out on some dragon-level pc hacking... literally. My notebook needs an "B&M Key 2242 Nvme SSD".
For that subset of SSDs, they are either unavailable/obsolete, of dubious quality or overpriced. Plainly speaking, short SSDs with two slots, but not SATA-type.
Short SSDs with the "wrong slot" (but of the right type) are cheaply available - you can see already where this is going... To check if this is even feasible,
pinouts of the two variants were compared. Looks good so far, we loose 2 of 4 PCIe lanes, but that should work out.
These are negotiated on boot and only "proved healthy" ones are used. So a fall-back to less lanes is anticipated.
Pinout is mostly the same, marked in red are the only incompatible contacts. Often a used contact on one is left open on the other, easing the requirements.
Hmm, only one way to find out for sure  I guess An SSD was luckily sourced locally, a slot cut very carefully with a tiny Dremel cut off disk, a bit of fine work with knife and file...
Incompatible contacts masked off with Kapton tape, and (with sweat beads on the forehead) inserted into the notebook, taking care not to push the tape away...
Works like a charm on first try, does not even complain about missing lanes, boots from device no problem 
Now to aquire one in the size I actually want and do it all over again 

[tggzzz]

It's slim, compact, rugged, easy to operate one handed...

Where that's important, I like the Metrix MX67, because the display is right by the UUT. I don't like "pen" meters with displays at right angles to that.

[Andrew_Debbie]

Racal Dana 9916 on eBay  listed as spares or repair.  Not shown powered on.    Current bid is £9.99

https://www.ebay.co.uk/itm/234466187300

520MHz, 8 digits.

Has (had?) Options  4B, 9 and 7

4B is the  5x10^-10/day oven oscillator. 
9 is LF multiplier
7 is the battery pack 


Option 9  adds   10Hz  to 25KHz.   with up to .001 Hz resolution.



On my watch list but I doubt I will be bidding.

[Vince]

It's slim, compact, rugged, easy to operate one handed...

Where that's important, I like the Metrix MX67, because the display is right by the UUT. I don't like "pen" meters with displays at right angles to that.

Did know about this MX67, never seen one for sale. Just looked it up... looks quite thick/chunky and its format factor and lack of tilting bale (which would useless/unstable even, if there was one) actually REQUIRES you to hold it with one hand, no choice. You can put it on the bench laying flat but then the display is pointing up so you can't see well.

The fluke 11 is a more versatile proposition I find. It's slimmer and does not require anything, you can use it in whatever fashion is most convenient to you at any time, one meter does it all.
Typically I would have the meter on my right hand side on its tilting bale, the TE under repair in front of me, and with my left hand (being left handed) I would probe around and still have my right hand free to operate the meter to switch for example from AC to DC when checking a power rail, or whatever.

I guess every one has its favorite workflow that suits him and his tools best...

[Robert763]

Post-purchase in-transit anxiety:  Schenker has got the 5316B package, likely in a storefront (they usually have supermarkets et c as agents, you can hand in shipments, and go pick them up, which is the cheaper way compared to delivery to your door. Also no issues with unguarded packages, they require photo ID to hand out packages and so on.) and I guess, based on the address of the sender that it is literally on the other beach from here.  (I live on an island in lake Mälaren, 3rd largest lake in Sweden) They still "have no delivery prognosis".

  

5316B OXCO question: Will the waveform of a home-brew Option 004 (OXCO) matter? All the cheap ones are square, but IIRC the original Option 004 board has a sine oscillator.

Would a 3-stage RC-filter with say 33KΩ and 4p7F in each stage work to smooth things out? (the part no on the drawing is not correct, assume an used CTI  10MHz OXCO.) I'm sort of pondering the output impedance resistor; do we need one just in front of the RC net too?

The OEM TCXO and OCXO output  a 1.2 V Pk-Pk sinewave.  I'd stick the squarewave through a filter/BALUN transformer from an old 10Mb/s Ethernet card. Alternatively bring it out on a BNC and link it to the external input which uses a diode clamp so will take a squarewave.

[med6753]

Indeed.  That's why my first DMM, which I bought brand new 25 years ago, a Fluke 11, is still my daily driver and the only one that sits permanently on the bench and goes in the toolbox when I go out or work on the car.... because despite it's 4000 count display and atrocious accuracy, 0.9% accuracy (though I measured it to be much better than this), is plenty good enough for general work, maintenance, repair, debugging during development of a project. It's slim, compact, rugged, easy to operate one handed, fat contrasting digits that are easy to read, good continuity test (fast, sensitive and latched), a stable tilting bale... and it has battle scars and patina... so I am not too worried about it, like I would be with a NIB rare and expensive MX56/C for example, which is also very bulky, unstable tilting bale, scratchy continuity test, needs to hands to rotate the main switch because of that. So I take it out of its drawer only when I need the extra performance or features, or if I just want to enjoy its pretty face and platy with it, of course 

Why do you think that nearly every time I show a picture of a voltage measurement it's the same DMM? 

[Vince]

Vref : that's destiny : I just said I was going to terminate the experiment... so I go to the bench to unplug every thing and put test leads back on to the test leads rack and...eh.. the red LED i snot lit any more ?!
Battery just went kaput, exhausted ! Looks like even the Vref itself decided it  was indeed time to put an end to this ! 

so I went to recharge it before putting it in storage somewhere yet to be determined and.... eh ? What the... oh no.... when I put the acrylic case back together after fixing the thing, I didn't pay attention to the USB port, the hole for the USB connector is not lined up with the hole in the case anymore, can't recharge it !    Had to take this case apart again... this thing is a pain, you can't just remove one piece... the 4 sides are meshed into one another, a rather unstable puzzle game I curse at when trying to put it back together and putting screws back in.
But, well... it's cheap I guess.. .you can't have it all...

[med6753]

Don't forget the allure of different display technologies, e.g. dekatrons, nixie, panaplex, HP's "dotted digits", etc. Numitrons have their charm too.

Due to my affinity to bat shit crazy redheads these ruby red LED's will always be my favorite. 

[Vince]

Indeed.  That's why my first DMM, which I bought brand new 25 years ago, a Fluke 11, is still my daily driver and the only one that sits permanently on the bench and goes in the toolbox when I go out or work on the car.... because despite it's 4000 count display and atrocious accuracy, 0.9% accuracy (though I measured it to be much better than this), is plenty good enough for general work, maintenance, repair, debugging during development of a project. It's slim, compact, rugged, easy to operate one handed, fat contrasting digits that are easy to read, good continuity test (fast, sensitive and latched), a stable tilting bale... and it has battle scars and patina... so I am not too worried about it, like I would be with a NIB rare and expensive MX56/C for example, which is also very bulky, unstable tilting bale, scratchy continuity test, needs to hands to rotate the main switch because of that. So I take it out of its drawer only when I need the extra performance or features, or if I just want to enjoy its pretty face and platy with it, of course 

Why do you think that nearly every time I show a picture of a voltage measurement it's the same DMM? 

DISQUALIFIED ! 

The Fluke 87 is hardly a cheap bare bone meter like the 10/11/12 are ! 
the 87 s a very nice meter, good accuracy, high count/resolution, good features, and expensive.

I would love to add one to my collection (have 4 old Fluke DMMs in all), but here at least, the Fluke brand markup is too much. They aren't good enough value for money. That's why I prefer buying Metrix MX 53/54/56, way better value for money overall.

I can't justify spending 90 euros on an old Fluke 73 say, or 75 ot 77 even, when the same money can get me a MX54/C for example. It just does not compute at all... 
So the few Flukes I do have, are only with me because I was lucky enough to find them at price point that makes sense.
If I can find a nice 87V for a price I like, I would buy it. Well, not now of course, no money for TE atm....

[BU508A]

Don't forget the allure of different display technologies, e.g. dekatrons, nixie, panaplex, HP's "dotted digits", etc. Numitrons have their charm too.

Due to my affinity to bat shit crazy redheads these ruby red LED's will always be my favorite. 

Keithley 616 dotted LED display:

[tggzzz]

It's slim, compact, rugged, easy to operate one handed...

Where that's important, I like the Metrix MX67, because the display is right by the UUT. I don't like "pen" meters with displays at right angles to that.

Did know about this MX67, never seen one for sale. Just looked it up... looks quite thick/chunky and its format factor and lack of tilting bale (which would useless/unstable even, if there was one) actually REQUIRES you to hold it with one hand, no choice. You can put it on the bench laying flat but then the display is pointing up so you can't see well.

The fluke 11 is a more versatile proposition I find. It's slimmer and does not require anything, you can use it in whatever fashion is most convenient to you at any time, one meter does it all.
Typically I would have the meter on my right hand side on its tilting bale, the TE under repair in front of me, and with my left hand (being left handed) I would probe around and still have my right hand free to operate the meter to switch for example from AC to DC when checking a power rail, or whatever.

I guess every one has its favorite workflow that suits him and his tools best...

That's pretty much correct.

I like the MX67 because it is small and held in the hand. It is great for just wandering around in an instrument from any angle and direction. That's very useful when probing deep inside a big/heavy instrument/rack. The military bought lots of them, so it is as rugged as the Fluke 25. No current measurement of course, but it does AC/DC voltage and resistance very well. The military bought lots of them, so it is as rugged as the Fluke 25.

In that respect, the Fluke 11 looks like any other multimeter to me. I normally use a Fluke 25 for that.

[med6753]

DISQUALIFIED ! 

The Fluke 87 is hardly a cheap bare bone meter like the 10/11/12 are ! 
the 87 s a very nice meter, good accuracy, high count/resolution, good features, and expensive.

I would love to add one to my collection (have 4 old Fluke DMMs in all), but here at least, the Fluke brand markup is too much. They aren't good enough value for money. That's why I prefer buying Metrix MX 53/54/56, way better value for money overall.

I can't justify spending 90 euros on an old Fluke 73 say, or 75 ot 77 even, when the same money can get me a MX54/C for example. It just does not compute at all... 
So the few Flukes I do have, are only with me because I was lucky enough to find them at price point that makes sense.
If I can find a nice 87V for a price I like, I would buy it. Well, not now of course, no money for TE atm....

Of the 10 Fluke DMM's in my stash the 87 is the only one I bought new in 1997. Yes, it wasn't cheap. 

[tggzzz]

Don't forget the allure of different display technologies, e.g. dekatrons, nixie, panaplex, HP's "dotted digits", etc. Numitrons have their charm too.

Due to my affinity to bat shit crazy redheads these ruby red LED's will always be my favorite. 

Keithley 616 dotted LED display:

Haven't seen those slotted displays before.

7 segment LEDs are boring, and so much less ergonomic and pleasing than

[tggzzz]

Anyway, enough display porn and meters... Back to tweaking a recent unnecessary addition to the herd.