Test Equipment Anonymous (TEA) group therapy thread

[0culus]

Got the urge to build another pulser. This time I laid it out so that I would be able to connect a charge line easily. This effort incorporates all the tricks I have learned in my journey of building Jim Williams' circuit.

(1) dual sided copper clad FR4, pure Chinesium. It was cheap, what can I say?
(2) Snip collector lead off 2N2369 and use the case to connect to the collector (it is internally tied to the collector like many metal case transistors)
(3) Use island cutter to make spots for soldering
(4) Transmission lines on the board (both for output and for the future charge line) are hand cut grounded coplanar waveguide. I measured carefully with calipers and I approximately match the dimensions several online calculators give me
(5) High quality Vishay thin film resistor is used for the termination on the output
(6) And last, but most certainly not least, this design conspicuously eliminates the 1 pF cap the original circuit uses. Instead, I put my microwave engineer hat on and am relying on the parasitic capacitance of the board. It works rather well!

Measurement set up today is my Type 547 'scope with the Type 1S1 sampling plug-in set to 200 mV/cm and 0.5 ns/cm. The output is going through a GR-874 20 dB (10X) pad.

[bitseeker]

On Aliexpress variate your search words and sort by price, eg. look for "lcr leads".

If you put them in the basket, ali shows what others bought, sometimes there is the same article much cheaper.

If something is linked here the price tends to go up.

Aw, man. Now TEA affects vendor prices, too?

[bitseeker]

The Fluke 8300A arrived yesterday, packaged pretty well to my pleasant surprise.  It powered up without a hitch and has been sitting connected to a resistance standard overnight.  It's within 2 ohms of the standard it's currently connected to, so I'd say the resistance functions, at least, seem to be operational.  I'll connect it to the DC calibrator later to see how it fares there, and perhaps try to get the AC one operational, too.  More photos to follow once I take a good series with the DSLR rather than the iPhone.

Glad it arrived safely! I messaged the seller about your buying it, just to see what'd happen. They said, "Wow, what a small world! Maybe your friend will give you visitation rights."

Is the front panel plate loose on the right side? It looked a bit like it in the listing.

Good eyes - the faceplate is a bit loose on the right side.




Won't know how it's attached until I open it up, but the rightmost two inches or so are separated from whatever is behind them, like delaminated plywood.

Ah, curious how it's attached. I shall look for your next post about it. I'll probably bump into it any page now.

[Andrew_Debbie]

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sehr sauber   (very clean)

[bitseeker]

Someone (Pat maybe?) once mentioned that HP made some 3311A in metal enclosure instead of plastic. Is that readily discernible in photos? The aluminum and plastic versions of the 3478A are easy to differentiate, but I've only ever seen the plastic version of the 3311A (that I know of).

I have a 3310A, 3310B, 3312A and 33120A. A non-plasticky 3311A might be nice.

I'm not familiar at all with the 3311A (had to look it up), so t'was not I.

I too have a 3310A & B, then my stable jumps to the 3314A (Still surprises me every time I pick it up how looooooong that thing is - you see this cute little half-rack-wide 3U faceplate on the shelf, then go to move it and realize the damned thing is 17" (~43 cm) long.  It sits next to the 8904A, which has a similar panel size, but it's 3" LONGER than the 3314A.  Deceptive little buggers!)

Ah, OK. I don't remember who said it previously.

Yeah, HP did make some long ones. The 5315/5316 are some others.

Well I couldn't find anything with the forum search, I do have to say I always thought the hp 3311A, 5300A series counters, 34740A series voltmeters had plastic cases, until  I found a 3311A at a local HAM sale, I then released they were actually in die-cast metal cases.
If you've seen a plastic cased 3311A, could it have been a very late production one???

Do you have a pic of the die-cast 3311A case?

Edit: Just caught up to your post with the teardown. Thank you! (Also adding to the POI.)

The case was die cast and was eventually redesigned to be a two part injection moulded. I think that didn’t happen until they worked out how not to make the insides quite as toasty as my 5381A which would have turned it into a pile of slag in about ten minutes flat  . Mine is die cast.

Ah, maybe you were the one who mentioned it before.

So, I should be looking for an enclosure that isn't a two-parter? (Saw David's pics.)

[bitseeker]

I had a fight with gimp regarding this Sisyphos Tekscope (I have used the 547).
Here are the results:

Difference is the lettering, EEVBLOG vs. EEVBlog


I created then a version with a transparent background and uploaded it to spreadshirt.
This is how it looks on their preview on their website (I do like the grey background):



If somebody is interested, I can upload the xcf files from gimp.

What do you think about this result? Any suggestions, comments, improvements?
@bd139: I did not convert it to a vector graphic image, because I don't know how to do this. 

That looks good! I couldn't find the shirt on Spreadshirt.

The PNG with alpha channel that you uploaded in a later post seems to have been altered. The alpha channel was gone.

Regarding converting a bitmap to vector, I don't think GIMP will do that. Inkscape might since it's a vector-based editor.

[bitseeker]

Well.... look what's on my bench today ? 

I always wanted one so badly, a Tek 575 hollow state transistor/curve tracer !   ... but too rare over here, and always 500 Euros "as is take it or leave it, don't ask pics or questions, untested", so not for me.
But perseverance finally paid off !  3 days ago one popped up ! and advertised at only 100 Euros on top of that, ie a MASSIVE BARGAIN !!!!     Ad did sport a "Make me an offer "button. So I clicked on that and offered well, the 100 Euros he was asking for. 30 seconds later I gave it a second thought and cancelled my offer, to make another one... 150 ! I saw the ad very late, 3 hours after it was published. That's an eternity. It was obvious by that time the seller had already been bombarded with 20 people wanting it, each offering more than the asking price hoping to get it. So I figured if I want even a slight chance of getting a response from the seller, even if negative.... would be to offer him more than the 100 Euros he asked, and offer sufficiently more that it might attract his attention and possibly, though unlikely, make me the highest "bidder".  I also gave him my phone number.
5 minutes later he calls me saying OK deal done. Got bombarded with 20 people, they offered me more than the 100 I asked, but your offer is the best, so deal done ! 
...

Well done, Vince! Congrats!

[bitseeker]

Here is the link to the HP 3311A.
https://www.ebay.com/itm/373611561435
By the looks of the wear & tear on the top and bottom, my guess is that it is actually a metal case.
It looks to my eye that the dings all show a bright metallic colouring.
However, at first glance, the shape of the case made me think plastic, hence the uncertainty.

Ah, OK. I do see some bare aluminum where the paint got scraped. So, that's a 1972 design. I'll do some more eye training. Thanks cyclin_al.

Hmmm, on closer look, someone photo-shopped out something from the photo of the top, on the top centre at the edge where it meets the front panel...

Maybe an inventory control tag.

[bitseeker]

OK, between you and Specmaster shilling Gixen, I tried it for an EQ guitar effect pedal that I've been wanting and ended up being the only bidder. I won it for a good price. I started browsing through the list of auctions ending soon and putting in lowball offers (using Gixen) on a bunch of Agilent bench DMM listings (which required buying an account). I don't think I'm going to win any of these, but I can see how eventually you would, if you kept on playing. Neat.

EDIT:

I have found this to be a real GAS-enabling technology.

I like it: Step on the GAS with Gixen!

[bitseeker]

Get yourself a wall of obsolete (?!?) transistors:

 

https://www.ebay-kleinanzeigen.de/s-anzeige/transistoren-itt-03648-fast-komplette-ve/1821843392-168-6987

And build yourself a Pong machine with discrete components: https://www.eevblog.com/forum/projects/oscilloscope-pong-for-1-or-2-players/

[bitseeker]

Take a look at the back of it, you can see the ends of the two black strips that latch the two case halves together, this is used on all of them I have (3311A, 5300 series & 34740 series) and mine all have die-cast metal case halves.

If you haven't seen Tony's 5300 video, then have a look at how they fit together.


David

OK then, they are die-cast and not sheet steel, thats why I thought they were plastic, looking at my own sheet steel enclosure, the returns on the front bezel are were angled at approx 33-45 degrees whereas mine are folded back on themselves with 3 screws a side.

Yeah, kind of tough when you haven't seen one in real life. Thanks for all the references!

[bitseeker]

Not sure if it's nit-picking to point out that this is LED, not VFD:
Nope. No it's not nit-picking, it's just accuracy.[/color][/size][/b]

You are too critical... over here sellers would not even be able to figure out it is a DMM... this ad is above average to me !

True that! Should be glad it didn't also have "Nixie" in the title. Gotta get all the juicy keywords in there.

[bitseeker]

Many people on this forum admit to having massive long repair queues, why get more gear than you can realistically repair? All that does is to fill your place with clutter and use up your funds, funds which could be used getting the parts you need to repair your latest addition. I dare say that many will find that by the time they get to fixing some items, that they then discover the parts you require are unobtainable and so becomes lost funds that could have been better used?

This is the TEA thread, right?

Those are good points, though. But, you know, TEA.

[mansaxel]

But the critical question is: Can you reflow in it? 

NFW! This is for steak and eggs, period.

[mansaxel]

But the critical question is: Can you reflow in it? 

Wouldn't try: too much chance of exploring the long term effects of PTFE getting too hot. Just use the cheapest saucepan with a glass lid

No PTFE is involved in the making of a Duossal pan; it's an aluminium outer shell (for heat conduction) with a stainless inner (because stainless is much better for your food, and won't break when you stir it), nothing more.

[bd139]

Got the urge to build another pulser. This time I laid it out so that I would be able to connect a charge line easily. This effort incorporates all the tricks I have learned in my journey of building Jim Williams' circuit.

(1) dual sided copper clad FR4, pure Chinesium. It was cheap, what can I say?
(2) Snip collector lead off 2N2369 and use the case to connect to the collector (it is internally tied to the collector like many metal case transistors)
(3) Use island cutter to make spots for soldering
(4) Transmission lines on the board (both for output and for the future charge line) are hand cut grounded coplanar waveguide. I measured carefully with calipers and I approximately match the dimensions several online calculators give me
(5) High quality Vishay thin film resistor is used for the termination on the output
(6) And last, but most certainly not least, this design conspicuously eliminates the 1 pF cap the original circuit uses. Instead, I put my microwave engineer hat on and am relying on the parasitic capacitance of the board. It works rather well!

Measurement set up today is my Type 547 'scope with the Type 1S1 sampling plug-in set to 200 mV/cm and 0.5 ns/cm. The output is going through a GR-874 20 dB (10X) pad.

That was a pretty tidy pulse that. I’m impressed.

I am possibly going down this rabbit hole as I found my large bag of 2369’s when I was tidying yesterday and have a 475 that needs testing 

[bd139]

Many people on this forum admit to having massive long repair queues, why get more gear than you can realistically repair? All that does is to fill your place with clutter and use up your funds, funds which could be used getting the parts you need to repair your latest addition. I dare say that many will find that by the time they get to fixing some items, that they then discover the parts you require are unobtainable and so becomes lost funds that could have been better used?

This is the TEA thread, right?

Those are good points, though. But, you know, TEA.

I’ve got the opposite problem. All my stuff works. There is no repair queue. Even the broken stuff was annoyingly easy to fix.

I’ve got a particularly good repair candidate on the watch list at the moment. It will almost certainly have more than one issue. If it doesn’t I’m going to be pissed  .

Based on Specmaster’s success I’m going to Gixen that one.

[BU508A]

I had a fight with gimp regarding this Sisyphos Tekscope (I have used the 547).
Here are the results:

Difference is the lettering, EEVBLOG vs. EEVBlog


I created then a version with a transparent background and uploaded it to spreadshirt.
This is how it looks on their preview on their website (I do like the grey background):



If somebody is interested, I can upload the xcf files from gimp.

What do you think about this result? Any suggestions, comments, improvements?
@bd139: I did not convert it to a vector graphic image, because I don't know how to do this. 

That looks good! I couldn't find the shirt on Spreadshirt.

The PNG with alpha channel that you uploaded in a later post seems to have been altered. The alpha channel was gone.

Regarding converting a bitmap to vector, I don't think GIMP will do that. Inkscape might since it's a vector-based editor.

The shirt isn't directly available at Spreadshirt, you need to design your own version of it by using an alpha-channel PNG.
I'll check this evening why is that and will replace it. Thanks for the heads-up. 
Btw, as a plan B, one can use one of the pictures from above and convert the white into transparent (which I did previously).

I tried Inkscape and found it worse than gimp using it. 

[BU508A]

Yeah, I know, I'm a bit late to the party but here are some pictures of my DIY Kelvin cable set, made with RG316.
The RG316 is a bit stiff but it's doing its job.

[...]

And here is my Kelvin cable set:



The bananas are 4mm Stäubli/MultiContact hollow plugs. I've soldered some wires to the shielding right under the heatshrinking tube next to the cable ties. The Kelvin clips itself I've bought in Belgium from this seller: https://www.ebay.com/itm/164360896467

Those are quite fetching. What's the reason for using coax and what is the shield connected to, and at which ends?

I ended up buying the AST-branded ones from an online retailer that shares its name with a large river in South America. They seem to be quite decent. They use 18AWG silly-cone wires and, as Marco Reps would say, "proper" banana plugs. I don't understand why they went for safety plugs since there will never be more than about 1V between them (I measured 0.910 volts while measuring a 20kR).  Maybe because a foolish person might measure the resistance of a charged 600V capacitor?

The shielding is neither connected to the red/black banana plugs nor the Kelvin clips. It stops right before it.
Only the cables with the green/yellow plugs are connected to the shield.
The reason is: for some sensitive measurements I've observed some spikes and wondered, if this would help to reduce them.
I also had the idea to use the shielding as a guarding but haven't tried that. Will report back, when I've made some measruements with the results.

[BU508A]

They also changed the management software (UNMS) that you run locally to require a cloud account. I'm guessing you just manage individual boxes via the web interface, or haven't updated UNMS in a while, or perhaps if you got in before they foisted cloud accounts on everyone then they let you carry on without one. The last time I tried to run up UNMS it wanted me to register a cloud account before it would play.

Congratulations to your 7777th posting here in the EEVBlog forum. 

[tggzzz]

Got the urge to build another pulser. This time I laid it out so that I would be able to connect a charge line easily. This effort incorporates all the tricks I have learned in my journey of building Jim Williams' circuit.

(1) dual sided copper clad FR4, pure Chinesium. It was cheap, what can I say?
(2) Snip collector lead off 2N2369 and use the case to connect to the collector (it is internally tied to the collector like many metal case transistors)
(3) Use island cutter to make spots for soldering
(4) Transmission lines on the board (both for output and for the future charge line) are hand cut grounded coplanar waveguide. I measured carefully with calipers and I approximately match the dimensions several online calculators give me
(5) High quality Vishay thin film resistor is used for the termination on the output
(6) And last, but most certainly not least, this design conspicuously eliminates the 1 pF cap the original circuit uses. Instead, I put my microwave engineer hat on and am relying on the parasitic capacitance of the board. It works rather well!

Measurement set up today is my Type 547 'scope with the Type 1S1 sampling plug-in set to 200 mV/cm and 0.5 ns/cm. The output is going through a GR-874 20 dB (10X) pad.

Pretty

Be good to see the output with the charge line too.

[tggzzz]

Hmmm, on closer look, someone photo-shopped out something from the photo of the top, on the top centre at the edge where it meets the front panel...

It is suspicious that they would go to that trouble for something that old. Maybe a "faulty do not use" sticker, or an indication that a gorilla has been in the vicinity?

[AVGresponding]

Quick update on the 2 Avo 8 Mk V meters I picked up this morning. The leads are in a pretty bad way, hopefully a good clean will improve them, but the probes have had it. One meter was in a near perfect leather case, the meter had a rattle when I got it home, opened it up and a little screw and washer fell out. Tested the DC volts and the meter reads a little low, further investigation reveals some damage to plastic movement protection shell, and it seems some plastic bits may be caught up in the meter movement as the meter is not linear. Need to investigate that more.

The other meter had a sticker on the side stating it had been serviced by Megger, who own Avo and that one checks out perfectly OK and still had the factory applied seal intact following its service. That does not mean to say it's free from faults, when they reassembled the meter, failed to correctly align the meter assembly with its plinth  and as a result has obscured the top of dial markings as you can see in the photo, 4,5 and 6, so this needs a little fettling. Otherwise, both meters are in good condition cosmetically and all the switches and cut-outs function correctly, and battery compartments are in original condition.

More info and photos as I get to grips with them.

Looking forward to seeing how they look with the lamps fitted!

 

[bd139]

That’s too old school. They’ve upped their game now

[bd139]

Ok replacement tinySA received already and confirmed genuine by Erik. Seller is good IMHO - they replaced it. I can't complain really.



This is probably best product support I've seen for a few years overall 

Now I've got 1.5 tinySA's I need to work out what to do with the 0.5 half. It sort of works with some constraints which I need to evaluate. It probably will make a reasonable signal source still or something