Test Equipment Anonymous (TEA) group therapy thread

[AVGresponding]

I've made good use of the time at home the last few days, got a replacement board designed for the shattered one in a 5264A plug-in, the board is a presetable divider, a variant of the decade divider board I had made for the 5245L.

I'm pretty sure I've recently seen a scrap pile with around a dozen of siblings of those.
Though no idea what was the subject line and it's practically impossible to see again an ad you actually want to see.
History search for the link was germanium, not very helpful for wider use.

https://www.ebay.com/itm/134619614975

Anybody with an idea behind decapping chips?
All I can think is a weight loss, but it's still work, and gear.

https://www.ebay.com/itm/115895320465

mjtronix is a well known TE rapist over here. The caps will have been gold plated, and he regularly sells butchered boards for "gold recovery" purposes.

[tautech]

Strangely not one piece of Agilent gear at the hospital, but lots of Philips.

Only saw Drager and more modern stuff in NZ when I had a visit a couple years back.

They thought I was nuts taking pics of this gear until I explained they were only specialised DSO's only capable of very low frequencies compared to modern electronics.
When home I looked up Mindray in China and my are they a massive crowd, based not far from Siglent HQ.

[Vince]

Well well well....

Just bought this thing 10 minutes ago !
Back from work, checked Leboncoin.fr and found this thing just popped up an hour prior, good luck.

It's a Metrix MX 52.

I think Specmaster or Tggzzz has one.

I have been meaning to add one to my collection of old Metrix ASYC meters for a while now, but never came across "the right one" for me.

The MX 50/51/52 series is quite rare/uncommon to begin with, it's mid range. Between the MX20, MX44 below it (2,000 and 4,000 counts, featureless, averaging) , and of course the MX 53/54/55/56 above (TRMS, 50,000 counts, feature packed and very accurate). It's got 5,000 counts, featureful and TRMS.


So they just don't pop up that often at all, and so far I could never find an ad I fancied. Either it was an entry level 50/51 not the top of the range 52. Or when it was a 52, it was either way overpriced and/or missing the jack cover, or defective, or in bad nick....

But the one that popped up today at long last, ticks all the boxes.

- A 52 not 50/51
- There is life on the screen, it's encouraging...
- Jack cover is present
- Excellent condition top and bottom.
- Price is not delirious, at 75 Euros, though still a tad on the high side, but not a show stopper given all the other boxes were ticked.

So I tried to get it a bit cheaper... offered the guy 60, made a counter offer at 65, deal done.
Add only 6 Euros for shipping and fees. For 71 Euros all in, this puppy shall be delivered to me soon.

I am happy 

A nice addition / new model to my Metrix collection, a gap has just been filled.

Now I need to pay for it and make room for it, so I think I will put one of my numerous MX 53 up for sale... I don't need so many of them do I ....

[EggertEnjoyer123]

Well, I'm back after a while of not posting.
I still haven't fixed my Tek 2236 yet (it seems like the MJE15030 can't be used as a replacement due to it's high fT, causing it to oscillate at 1MHz instead of the desired 20kHz). I did fix my PLL project that has been on the backburner for a while by changing the loop bandwidth from 30kHz to 300kHz. Now my PLL seems to do as well as a commercial module I bought at the swap meet a while back.

Here is a picture of my PLL at 18GHz vs a commercial 18,472.5 MHz PLL. As you can see they're pretty similar.

I'll probably get around to posting the design files sometime. I still have many unimplemented features in software, as well as some hardware issues (such as the MCU not resetting properly). There's also shielding problems.

There's only two modifications to the FM board needed to get my board to work. One is bypassing the input voltage divider when the machine is switched to the PL mode. The other is using a diode and resistor to pull down the gate of one of the JFETs to prevent the FM tuning sensitivity from changing when the bands switch.

[TERRA Operative]

New toy day!

This time it's a Siglent SPD3303X-E, which I have promptly hacked to an SPD3303X. 
It's great so far, except that the output jacks are NOT 19.05mm (3/4") apart like is standard on practically EVERY other piece of equipment with two or more binding posts.....   

Looks nice next to my other Siglent gear though, with the Keysight in there to keep them all in line. 


This will be replacing my HP/Agilent E3610A and two E3611A, basically a direct replacement output voltage/current wise (with a bit more overhead from the Siglent) plus the benefit of precise digital control instead of the 10-turn pots of the HP/Agilent units.
The HP/Agilent units are great and I do love them (I'm keeping the E3612A as its ranges are way up at 60V/120V) but dialing them in can sometimes be a bit of a fiddle when you want a super precise voltage or current.



Oh, I also finalised the design and construction of the 3GHz input option for my HP 53132A counter that I was building since late last year (and another one I stuck in the 53181A that I restored for my brother). They work great, not perfectly inline with the HP spec up the top end of the frequency range, but perfectly usable enough for me to call them done. However down the bottom end they are waaaayyyyy more sensitive which is nice. No spurious counting with no input connected too! 

The blue line in the PDF file is the minimum input for a signal lock, anything in the white is better than HP spec, anything in the grey is worse.

The test setup was a function gen feeding a sine wave into an Agilent 11667A splitter, one side to an Agilent N8482A power sensor connected to an Agilent E4418B Power Meter, the other side connected directly to the counter input (with attenuators added to provide lower signal levels than the power sensor could measure where needed).


I'm calling this project done until someone smarter than me can help simulate or otherwise improve the layout of the the PCB to optimise design for better high frequency performance. 

[wkb]

WOT? Replacing The True -HP- [tm] with Siglent?   

[factory]

Needs to be returned, so Siglent can fix their non-standard jack spacing. 

David

[BreakingOhmsLaw]

This will be replacing my HP/Agilent E3610A and two E3611A[...]

You might want to reconsider that. The SPD has it's issues. I have a board with a buck converter that reliably and reproducibly blows up when I power it from my SPD3303. I believe the reason is that the buck switching frequency is causing the regulation to malfunction and make the output voltage go to maximum.
My SPD also blew up and was repaired under warranty. That was the overheating bridge rectifier issue that Dave also noticed in his teardown.
All in all, the SPD3030 design was not Siglent's finest hour.

[tautech]

This will be replacing my HP/Agilent E3610A and two E3611A[...]

You might want to reconsider that. The SPD has it's issues. I have a board with a buck converter that reliably and reproducibly blows up when I power it from my SPD3303. I believe the reason is that the buck switching frequency is causing the regulation to malfunction and make the output voltage go to maximum.
My SPD also blew up and was repaired under warranty. That was the overheating bridge rectifier issue that Dave also noticed in his teardown.
All in all, the SPD3030 design was not Siglent's finest hour.

Latest units like Terra's are the new HW with inline bridges, not the tiny 2A circular ones in earlier HW.
Earliest units gave no issues but bridge suppliers must have changed or skimped on ratings and we started to see problems so the HW was changed and bridge uprated.
There are also changes to how the UI displays Series and Parallel modes that unfortunately can't be applied to earlier HW. 

[Vince]

Boy that was quick, I have already received the meter ! 

Quick test ride.

- Needs a good cleaning...

- LCD window needs sanding/polishing, lots of scratches

- LCD is a tad dim at a normal viewing angle. Thought maybe battery is weak but no it's brand new and kicking ass. My tongue is still recovering.
So maybe some zebra strips need reseating or cleaning. Though I have to confess, after 30 minutes using it, it seemed to improve. So maybe just needs to be used and it will be fine.
Maybe it's been sitting for many years.

- Diode test : works

- Current ranges : work

- "ADP" range : no idea what this mode does, need to go download the manual to learn about it

- Frequency measurement : fine, mains reads 50,0 Hz

Now for the stuff that doesn't quite work : some "ghosting" going on.

- Ohms range : open circuit, it reads 4+ Megs....
If I short the probes, reads 0 as it should. If I measure precision resistors, it reads up to 10% off. The higher the resistance value the higher the discrepancy, well more or less :

350 reads 349.8
916,67 reads 906
1K reads 985 or 988 (have two of them)
10K reads 9.3+ K
30K reads 27.75K
50K 45.5K

So my theory is : it's got a leak in the front end that makes it read 4+ Mg open-circuit. A constant leak would be like putting a 4.5Meg resistor in // with the actual resistor I am trying to measure. So it makes sense that it affects the reading more and more as the resistor under test is high in value.

- Vdc : open circuit, it reads negative 2.5 or 3.7V ! 
if I short the probes I get a solid 0.001 and if I measure the voltage of my lab supply varying from 0 to 30V, it reads just fine. So it's only open-circuit that it displays this gigantic ghost voltage.

- Vac : 5mv open-circuit. If I measure mains I get 230V or so, as does my Fluke 11 (it's winter, mains voltage is very low compared to summer where I get almost 250V)
So the problem only affects the DC path not AC.



So to sum it up, ghost readings in ohms and DC volts.
Probably a dirty PCB/front end... I will crack it open this week-end to give it a good clean inside out, might fix the problem.... if not, will need to investigate.

Will download the manual to learn how to use its many features, because the buttons labeling is kinda cryptic, sometimes it feels like I am reading an assembly language source code or something.... press this button to load register A into the accumulator, press this button to store it into register A0[y].... it's not exactly as intuitive as my MX 53/54/56 for example.
But... in some masochistic way, I find it kinda cool actually ! Feels very geeky I guess ?! 

 

[shakalnokturn]

Hey Vince!

I saw that one going, wasn't interested though. (I am quite jealous of the person who grabbed that MX56 for 30€ though!)
It's a shame about whoever shortened the banana skins on yours.
I've had some before and I think it's the only one of the mid-range worth keeping, still I'm no longer keeping them.
The one thing I do like much is the ON/OFF key.
ADP is for external adapters / sensors.

Often the screen window splits in the corners, the display being weakish is typical of the zebra strips on these, some editions have a trimmer for the LCD contrast.

I can only agree with your theory on the leakage, this is usually caused by battery leakage and made worse by the black foam that stores it AGM style. So when you do scrub it down, make sure you rinse the foam thoroughly. I once had one of the family so badly impregnated that the battery voltage had caused a char in the foam that I didn't spot at first (black on black) it had me searching for the leakage current once reassembled, the thermal cam showed a hot-spot on the foam.

If you come to needing readjustment I have notes on that, actually the photo might already be around EEVBlog.

Just to make you need one here's a picture of a rarer beast: The automotive MX63.
In terms of electronics it's somewhere in between the 52 and 53, trimmer adjustable but uses an ITT ASYC rather than a Maxim ADC.

[TERRA Operative]

I'll see how I go with the Siglent. As Tautech mentioned, it is a late hardware revision so hopefully it won't have the issues like the earlier revisions.

I primarily got it to give me precise digital control over the voltages as well as save some bench space, rather than the 'hold your tongue at the right angle while tweaking the knobs' of the HP units.
They won't be sold off immediately so I'll be able to fall back if I need anyway.

I'd like to open it up and have a look inside (maybe throw some heatsinks on vregs for fun etc), but I don't want to break the anti-tamper sticker and then later need warranty so sealed up it shall stay for now. 

[Vince]

Hey Vince!

I saw that one going, wasn't interested though. (I am quite jealous of the person who grabbed that MX56 for 30€ though!)

Hello Chacal, long time no hear 

An MX 56 for 30 Euros ?! 
Can't remember that one, guess either something was wrong with it, or the seller had no idea what he was selling ! 
Guy who bought it sure got the deal of the decade...

It's a shame about whoever shortened the banana skins on yours.

Nah, no worries, these are the original Metrix test leads, which are crap. Good riddance... straight to the bin.
I have never understood why Metrix put crappy leads even on their top of the range MX 53/54/56 meters.
It's like selling a 200K Ferrari with crappy Chinese tires. Makes no sense and is a disgrace.

The one thing I do like much is the ON/OFF key.

Yes I forgot to mention that, but it's indeed a nice "feature"... Somehow it is so rare on meters 
Makes it easier on that poor range switch, and allows you to power up the meter right away on your last / favorite / most used range/function.

ADP is for external adapters / sensors.

Oh I see....
I just downloaded the "manual" (attached) for it.... well Google couldn't find me an actual manual, all I can find is this document that's more like marketing material, an 8 page brochure/ datasheet. Better than nothing, gives some info at least.

They do mention the ADP mode... as you say it's for external sensors. It's basically a fixed 500mV volt meter range, with no units displayed.
"ADP" stand for "ADaPter". Makes sense...

Datasheet says the MX 52's accuracy is 0.1% ? Wow that's as a good a MX 53.  Quite nice for a mid-range 5,000 count meter.

Often the screen window splits in the corners,

Yes, though for some reason I see it mostly (if not uniquely) on the Yellow cased meters, so the MX57Ex, but can't remember seeing it on the "regular" blue/grey models.
Maybe the additives used to obtain that yellow colour somehow degrade slightly the mechanical characteristics of the plastic, and it fails at the weakest point... those corners. Who knows...

the display being weakish is typical of the zebra strips on these, some editions have a trimmer for the LCD contrast.
I can only agree with your theory on the leakage, this is usually caused by battery leakage and made worse by the black foam that stores it AGM style. So when you do scrub it down, make sure you rinse the foam thoroughly. I once had one of the family so badly impregnated that the battery voltage had caused a char in the foam that I didn't spot at first (black on black) it had me searching for the leakage current once reassembled, the thermal cam showed a hot-spot on the foam.

If you come to needing readjustment I have notes on that, actually the photo might already be around EEVBlog.

Thanks for the help, will look into that this week-end probably... the weather here is absolutely catastrophic, so I need to stay busy with some indoors occupation 

Just to make you need one here's a picture of a rarer beast: The automotive MX63.
In terms of electronics it's somewhere in between the 52 and 53, trimmer adjustable but uses an ITT ASYC rather than a Maxim ADC.

Oh yes I think I remember seeing that one, not that long ago. I opted not to buy it for I can't remember what reason... probably overpriced and me not needed the extra automotive feature... setting ignition points was fun in the 70's and early '80's, but I prefer early '90's cars and we had electronic injection by then 

But yeah, if I come across one that's cheap enough to my taste, might be tempted just for the sake of enriching my ASYC collection 

[shakalnokturn]

I don't hang out on TEA much, my addiction level is low enough. (Unless it's the denial level that's high enough...)
Things seem very quiet here since I last checked-in !

The MX56 seller had no clue what he was selling (no proof it was working correctly though) it was gone within minutes, had the blue protective holster too.
He later sold an MX53 in worse condition at a higher price. And I ended up buying (yet another) cheap MX240 from him because no one seems to know how good they are, you don't get that many options for a DC power / energy capable clamp meter at 40€.

Original test leads aren't the most convenient to use but they do have the ASYC locking notch that is some kind of use if the socket cover is a requirement for you.

I have the paper booklet for the MX51/52 meters I just need to get down to finishing the scan some time... I think Specmaster also asked me for it some time back.

I've seen / had a fair deal of black cases with cracked windows too.

The other common issue I forgot is the contacts dropping off the rotary switch, I recommend that you at least open it to check they aren't coming loose.

The more recent MX63 is still around, I don't pay 210€ for a handheld DMM whatever it is, didn't even bother with a FLuke 189 in new condition with carry pouch, software, IR interface, and other accessories for 150€ maybe I should have... I got my MX63 in similar state to your MX52 for just over 40€.
To me it looks as if the AC/DC current clamp adapter is made by APPA can anyone confirm this?
I doubt I'll ever use the "Autometrix" features, I just appreciate its seldomness.

[44kgk1lkf6u]

You might want to reconsider that. The SPD has its issues.

I learned that they were bad at making firmware when I had to connect it to a computer for reasons.  It does not support a space following a comma in an SCPI command.  But it does allow the output voltage and current to be set to NaN after which there seems to be no way to set it back with the knob.

[Vince]

[..] my addiction level is low enough. (Unless it's the denial level that's high enough...)

I would vote for the latter ! 

And I ended up buying (yet another) cheap MX240 from him because no one seems to know how good they are, you don't get that many options for a DC power / energy capable clamp meter at 40€.

You would get along with Robert, he has an addiction for current clamps, I wonder if he has one of these in his collection...

Original test leads aren't the most convenient to use but they do have the ASYC locking notch that is some kind of use if the socket cover is a requirement for you.

The notch hmmm... never paid attention to that I am must admit. I don't care about the feature of the safety cover to be hjonest, locking or not I do'nt feel like my life is at risk.. if it were Fluke and anybody else would not sell a single meter.  Hell even  Metrix themselves gave up on this cover in the later / last revisions of these meters. The red coloured ones. Somehow they decided to keep the cover on the bottom of the range MX20, not sure why.
So no, not bothered the slightest bit about using notch-less / regular leads on my ASYC meters. The only reason I want the cover is that, and this is a highly scientific, extremely well technically grounded opinion... is that without this cover, I find these meters absolutely... butt ugly !    Like something is missing. It just ruins their look.
Yes, TEA is not only about features and performance.... looks counts as well, given the choice. Like my old hollow state Tektronix scopes : Form AND Function ! Why chose when you can be given both...   

I have the paper booklet for the MX51/52 meters I just need to get down to finishing the scan some time... I think Specmaster also asked me for it some time back.

Oh yeah that would be great, please ! 

I've seen / had a fair deal of black cases with cracked windows too.

Hmm, so I got lucky with all those I bought then. My colour theory is out the window then.... maybe it's just meters that came without a rubber holster, and careless users banging the meter all the time. Just like they ruin the crap out of the sides of the meter with  a screw driver to try to crack it open to replace the battery, instead of reading the manual and using the dedicated prying tool that's attached to the back of the meter....

The other common issue I forgot is the contacts dropping off the rotary switch, I recommend that you at least open it to check they aren't coming loose.

Ah, didn't think of that. Will be sure to have a look...

The more recent MX63 is still around, I don't pay 210€ for a handheld DMM whatever it is, didn't even bother with a FLuke 189 in new condition with carry pouch, software, IR interface, and other accessories for 150€ maybe I should have... I got my MX63 in similar state to your MX52 for just over 40€.

Ah yeah, at 40 Euros I would definitely buy one as well ! 

[Robert763]

I have a MX1200S (badged badged HEME 1000P) and a HEME 20P ...

[Robert763]

Front panel is installed and looking pretty good! 

I have a few minor adjustments to make, almost inconsequential but just to make it 100% perfect.
Also, as it is plastic, there is a bit of flex to the front panel. Once it's mounted it's much more rigid, but I might make a '3D Print' version with some strengthening ribs on the back side.

Next step, figure out the cheapest way to get it made in aluminium....  (It ain't gonna be cheap....)

Did you progress this? I noticed a genuine 8648C front panel for sale locally at £35
Robert.

[factory]

Just seen that too. https://www.ebay.co.uk/itm/335273185003

David

[factory]

Well ebay.com are saving me a fortune  , ever since they changed the Global Shipping Programme to Ebay International Shipping, I've been unable to buy any TE from the USA, it's getting very annoying, as most sellers don't give a damn and only ship via the Ebay provided service. Of course TE manuals are still available via the crap Ebay International Shipping disservice, with no combined discounts & overpriced shipping.

Now I'm looking at alternate ways to buy & export TE from the USA, one method seems to use Shipito, is this company any good, or should I be looking elsewhere?

David

[tggzzz]

Well ebay.com are saving me a fortune  , ever since they changed the Global Shipping Programme to Ebay International Shipping, I've been unable to buy any TE from the USA, it's getting very annoying, as most sellers don't give a damn and only ship via the Ebay provided service. Of course TE manuals are still available via the crap Ebay International Shipping disservice, with no combined discounts & overpriced shipping.

Now I'm looking at alternate ways to buy & export TE from the USA, one method seems to use Shipito, is this company any good, or should I be looking elsewhere?

David

Yeah

Letting fleabay do the customs/export documentation is convenient, and they take the risk of incorrect declarations.

I've had someone in Portugal that wanted me to avoid using GSP. One valid complaint is that fleabay tracking only works well until the package reaches the destination country. It doesn't show movement to the destination address.

No idea about other shipping mechanisms.

[factory]

Forgot to post a typical example of the eBay International Shipping failure on ebay.com and it's not just TE that we Brits are not able to buy from the USA, since GSP got downgraded to the new eBay provided dis-service, I fully understand sellers not wanting the risk of sending things direct, as the seller only has to worry about getting the item to ePay's warehouse in the origin country.

Wonder if the buyer in Portugal didn't like the shipping price quoted by GSP, then again regular shipping is often just as expensive, or more expensive.

P.S. another item of TE I was looking last month, had no shipping to anywhere outside of the USA, this was due to the seller incorrectly listing it under a military related category, of course they didn't believe me and were adamant the item had worldwide shipping via eBay International Shipping. 

David

[tggzzz]

Forgot to post a typical example of the eBay International Shipping failure on ebay.com and it's not just TE that we Brits are not able to buy from the USA, since GSP got downgraded to the new eBay provided dis-service, I fully understand sellers not wanting the risk of sending things direct, as the seller only has to worry about getting the item to ePay's warehouse in the origin country.

Wonder if the buyer in Portugal didn't like the shipping price quoted by GSP, then again regular shipping is often just as expensive, or more expensive.

David

I don't know the reason(s).

The other hiccup can be import duties and VAT, which wouldn't (directly) bother the seller.

[Kosmic]

Forgot to post a typical example of the eBay International Shipping failure on ebay.com and it's not just TE that we Brits are not able to buy from the USA, since GSP got downgraded to the new eBay provided dis-service, I fully understand sellers not wanting the risk of sending things direct, as the seller only has to worry about getting the item to ePay's warehouse in the origin country.

Wonder if the buyer in Portugal didn't like the shipping price quoted by GSP, then again regular shipping is often just as expensive, or more expensive.

David

I don't know the reason(s).

The other hiccup can be import duties and VAT, which wouldn't (directly) bother the seller.

it's the same for Canada. I get everything delivered at my depot just across the border now 

[TERRA Operative]

Front panel is installed and looking pretty good! 

I have a few minor adjustments to make, almost inconsequential but just to make it 100% perfect.
Also, as it is plastic, there is a bit of flex to the front panel. Once it's mounted it's much more rigid, but I might make a '3D Print' version with some strengthening ribs on the back side.

Next step, figure out the cheapest way to get it made in aluminium....  (It ain't gonna be cheap....)

Did you progress this? I noticed a genuine 8648C front panel for sale locally at £35
Robert.

No progress yet, the $400 to get the part machined in aluminium is well above my budget at the moment....

Is the one you found an LCD or VFD model (or does it come with the display too) for a reasonable price?