Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

Hamfest haul. Mostly ARRL books for eBay. Trying to keep purchases reasonable for house move. Bumped into Robert and tggzz.

1x HP 427A (thanks Robert)
1x HP 3456A £15
1x Tek 2465 SMM £5
2x QRP classics £1
1x Solid state design 50p
1x QRP power 50p
1x ARRL handbook 80p
1x Design notebook 80p

Books bounce for £15-35 each. Fuel covered 

Nice haul, but what is that to the left of the HP427A? That is not a HP 3456A, not big enough for a 6.5 digit meter.

[AVGresponding]

Hamfest haul. Mostly ARRL books for eBay. Trying to keep purchases reasonable for house move. Bumped into Robert and tggzz.

1x HP 427A (thanks Robert)
1x HP 3456A £15
1x Tek 2465 SMM £5
2x QRP classics £1
1x Solid state design 50p
1x QRP power 50p
1x ARRL handbook 80p
1x Design notebook 80p

Books bounce for £15-35 each. Fuel covered 

Nice haul, but what is that to the left of the HP427A? That is not a HP 3456A, not big enough for a 6.5 digit meter.

Not to mention that the 3456A is a full rack width unit. It is a 3465A.

[Specmaster]

Hamfest haul. Mostly ARRL books for eBay. Trying to keep purchases reasonable for house move. Bumped into Robert and tggzz.

1x HP 427A (thanks Robert)
1x HP 3456A £15
1x Tek 2465 SMM £5
2x QRP classics £1
1x Solid state design 50p
1x QRP power 50p
1x ARRL handbook 80p
1x Design notebook 80p

Books bounce for £15-35 each. Fuel covered 

Nice haul, but what is that to the left of the HP427A? That is not a HP 3456A, not big enough for a 6.5 digit meter.

Not to mention that the 3456A is a full rack width unit. It is a 3465A.

That is what I thought, it is an early version of my HP 3466A and is a hell of a lot bigger as well.

[bd139]

It is a 3465A. Dyslexic moment 

[Cerebus]

Boring Mundane Everyday Print #312: Meanwell PSU Endcaps   

         AutoDesk Online 3D Viewer

I've had this ugly-ass Meanwell 24V PSU on my desk ever since the original power brick from my 32" Cinema display kakked. I finally got tired enough of looking at it to do something; I decided to whip this out so I could put it away.

Endcaps are a press-fit, and allow for use of a salvaged C14 socket and DC power cord from an old AiO PC. And I finally found a use for Deans' connectors that doesn't make me wanna cringe.     This is actually part 1 of a bigger project; if part 2 is successful, I'll update with more pics.

As always; full details and 3DP nerd stats are over on the 3DP thread:

https://www.eevblog.com/forum/3d-printing/3d-printer-yet/msg4188976/#msg4188976

mnem

I'm in two minds about this.

On the one hand it's neat and does improve the safety of the PSU, covering up bare mains terminals. On the other hand that's a PSU that's designed to be fully enclosed, in particular the mesh that's on it doesn't meet, and was never intended to meet, safety rules for Nicht gefingerpoken, nicht cokensplaschen. So having a more consumer friendly wrapping with an IEC 60320 socket about the naked OEM supply makes it more likely that it might get used or handled in situations and by people who shouldn't use it. The "it's obviously made to be plugged in" look versus the "it's obviously made for experts" look make it a temptation for fiddling with by the uninformed and unwary.

In your own house it's down to how likely other people are to obey a "This here. Don't touch! Only for use of chief monkey!" instruction but I'm still not too sure that I'd be comfortable with it in my house where compliance is a dead certainty. If it were my house and used on a monitor where someone might conceivably go "It's not working, I'll follow the cables with my fingers behind this desk while leaning over it wearing this metal chain around my neck to see if it's got power" I'd be much happier putting it in an earthed metal case or a proper double insulated enclosure.

Perhaps a 3DP case that fully encloses it ought to go into the design queue. If nothing else, the challenge of designing one for 3DP that meets ventilation and Nicht gefingerpoken, nicht cokensplaschen requirements (e.g. IEC 60950) ought to be an interesting challenge.

[ch_scr]

Boring Mundane Everyday Print #312: Meanwell PSU Endcaps   

         AutoDesk Online 3D Viewer

I've had this ugly-ass Meanwell 24V PSU on my desk ever since the original power brick from my 32" Cinema display kakked. I finally got tired enough of looking at it to do something; I decided to whip this out so I could put it away.

Endcaps are a press-fit, and allow for use of a salvaged C14 socket and DC power cord from an old AiO PC. And I finally found a use for Deans' connectors that doesn't make me wanna cringe.     This is actually part 1 of a bigger project; if part 2 is successful, I'll update with more pics.

As always; full details and 3DP nerd stats are over on the 3DP thread:

https://www.eevblog.com/forum/3d-printing/3d-printer-yet/msg4188976/#msg4188976

mnem

I'm in two minds about this.

On the one hand it's neat and does improve the safety of the PSU, covering up bare mains terminals. On the other hand that's a PSU that's designed to be fully enclosed, in particular the mesh that's on it doesn't meet, and was never intended to meet, safety rules for Nicht gefingerpoken, nicht cokensplaschen. So having a more consumer friendly wrapping with an IEC 60320 socket about the naked OEM supply makes it more likely that it might get used or handled in situations and by people who shouldn't use it. The "it's obviously made to be plugged in" look versus the "it's obviously made for experts" look make it a temptation for fiddling with by the uninformed and unwary.

In your own house it's down to how likely other people are to obey a "This here. Don't touch! Only for use of chief monkey!" instruction but I'm still not too sure that I'd be comfortable with it in my house where compliance is a dead certainty. If it were my house and used on a monitor where someone might conceivably go "It's not working, I'll follow the cables with my fingers behind this desk while leaning over it wearing this metal chain around my neck to see if it's got power" I'd be much happier putting it in an earthed metal case or a proper double insulated enclosure.

Perhaps a 3DP case that fully encloses it ought to go into the design queue. If nothing else, the challenge of designing one for 3DP that meets ventilation and Nicht gefingerpoken, nicht cokensplaschen requirements (e.g. IEC 60950) ought to be an interesting challenge.

It's an old-ass mac. Nobody (besides the dwagon himself) gonna use it voluntarily anway 

[TERRA Operative]

As long as there are no 3 year olds, I doubt that an adult can get their fingers through that mesh...

[Brumby]

How old is the Dwagon, then....?   

[TERRA Operative]

At least 4 or 5 I think...    hahahaha

[bd139]

Hold my beer while I get my screwdriver 

Ok quick update:

HP 427A looks mostly tidy. Two of the pots have corrosion which will need dealing with somehow, possibly via replacement. There is also a completely unique NiCd battery pack and charger option in it which is not documented anywhere on the face of the planet. TBD. Otherwise complete and quite tidy under the usual grub. Big thanks to Robert

HP 3465A is tidy but quite sick. Haven't done a functional check properly yet but there's a bias issue somewhere which is causing it to be well off zero.

Now I will proceed to throw them in the cupboard of doom and ignore them for 3 months until other stuff sorted

[Brumby]

At least 4 or 5 I think...    hahahaha

I'm not sure if that sounds generous or not.


I don't think it matters anyway ... I just remembered what he said about fingers...   

[factory]

Hamfest haul. Mostly ARRL books for eBay. Trying to keep purchases reasonable for house move. Bumped into Robert and tggzz.

1x HP 427A (thanks Robert)
1x HP 3456A £15
1x Tek 2465 SMM £5
2x QRP classics £1
1x Solid state design 50p
1x QRP power 50p
1x ARRL handbook 80p
1x Design notebook 80p

Books bounce for £15-35 each. Fuel covered 

Nice haul, but what is that to the left of the HP427A? That is not a HP 3456A, not big enough for a 6.5 digit meter.

Not to mention that the 3456A is a full rack width unit. It is a 3465A.

That is what I thought, it is an early version of my HP 3466A and is a hell of a lot bigger as well.

I wouldn't call it an early version as they are not quite the same, the 3466A has True RMS AC and the 3456A/B is only Average Responding on AC, 3466A also has diode check function and had a higher price than the 3456A/B.

David

[Cerebus]

As long as there are no 3 year olds, I doubt that an adult can get their fingers through that mesh...

I think the actual real risk is a Bumblebutt propelled loose screw or tool knocked off the back of the bench.

I'm not gonna own up to the number of those style of PSUs that I've fried with a dropped tool/part when they're inside some other equipment that I've been conducting open chassis/case measurements with the power on. Let's just say that the number is higher than zero... [Fx: wanders off whistling an innocent tune]

Some people can get a bit anal about electrical safety and strictly they are right, but when it comes to stuff that stays in the lab I'm prepared to be a bit more laissez-faire as long as people aren't being idiots and some sort of actually useful risk assessment has gone through their heads. So I'm most definitely not saying this is out and out dangerous, just "Is it worth considering something a bit more enclosed?".

[TERRA Operative]

So, I have a nixie clock here using IN-16 tubes and one of the six is going dark.. The rest look perfect.
If the inside of the tube is going black (looks like metal sputtering), is there any way to reverse this or is the nixie toast?

[factory]

Hold my beer while I get my screwdriver 

Ok quick update:

HP 427A looks mostly tidy. Two of the pots have corrosion which will need dealing with somehow, possibly via replacement. There is also a completely unique NiCd battery pack and charger option in it which is not documented anywhere on the face of the planet. TBD. Otherwise complete and quite tidy under the usual grub. Big thanks to Robert

HP 3465A is tidy but quite sick. Haven't done a functional check properly yet but there's a bias issue somewhere which is causing it to be well off zero.

Now I will proceed to throw them in the cupboard of doom and ignore them for 3 months until other stuff sorted

Is the 427A similar to mine, AC power & NiCd fitted, with Bulgin mains connectors, German made.
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3561941/#msg3561941

Seems to be option H29 going by the overpriced one on feEbay.

David

[Specmaster]

As long as there are no 3 year olds, I doubt that an adult can get their fingers through that mesh...

I think the actual real risk is a Bumblebutt propelled loose screw or tool knocked off the back of the bench.

I'm not gonna own up to the number of those style of PSUs that I've fried with a dropped tool/part when they're inside some other equipment that I've been conducting open chassis/case measurements with the power on. Let's just say that the number is higher than zero... [Fx: wanders off whistling an innocent tune]

Some people can get a bit anal about electrical safety and strictly they are right, but when it comes to stuff that stays in the lab I'm prepared to be a bit more laissez-faire as long as people aren't being idiots and some sort of actually useful risk assessment has gone through their heads. So I'm most definitely not saying this is out and out dangerous, just "Is it worth considering something a bit more enclosed?".

I have one of those power supplies feeding 5 USB sockets on my bench. Its tucked away at the end of the bench away from everything else and so far no problems whatsoever with it.

[bd139]

Hold my beer while I get my screwdriver 

Ok quick update:

HP 427A looks mostly tidy. Two of the pots have corrosion which will need dealing with somehow, possibly via replacement. There is also a completely unique NiCd battery pack and charger option in it which is not documented anywhere on the face of the planet. TBD. Otherwise complete and quite tidy under the usual grub. Big thanks to Robert

HP 3465A is tidy but quite sick. Haven't done a functional check properly yet but there's a bias issue somewhere which is causing it to be well off zero.

Now I will proceed to throw them in the cupboard of doom and ignore them for 3 months until other stuff sorted

Is the 427A similar to mine, AC power & NiCd fitted, with Bulgin mains connectors, German made.
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3561941/#msg3561941

Seems to be option H29 going by the overpriced one on feEbay.

David

Yea that’s the one. Any idea where I can get a bulgin plug for it?

If the rest of it works ok I’m probably going to build a modern battery module for it. Might end up with a USB-C socket in it 

[factory]

So, I have a nixie clock here using IN-16 tubes and one of the six is going dark.. The rest look perfect.
If the inside of the tube is going black (looks like metal sputtering), is there any way to reverse this or is the nixie toast?

Probably trash, I've got a clock from TE manufacturer and all the tubes are dim due to metal sputtering, from decades of continuous use, at least IN-16 tubes are readily available.

David

[factory]

Hold my beer while I get my screwdriver 

Ok quick update:

HP 427A looks mostly tidy. Two of the pots have corrosion which will need dealing with somehow, possibly via replacement. There is also a completely unique NiCd battery pack and charger option in it which is not documented anywhere on the face of the planet. TBD. Otherwise complete and quite tidy under the usual grub. Big thanks to Robert

HP 3465A is tidy but quite sick. Haven't done a functional check properly yet but there's a bias issue somewhere which is causing it to be well off zero.

Now I will proceed to throw them in the cupboard of doom and ignore them for 3 months until other stuff sorted

Is the 427A similar to mine, AC power & NiCd fitted, with Bulgin mains connectors, German made.
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3561941/#msg3561941

Seems to be option H29 going by the overpriced one on feEbay.

David

Yea that’s the one. Any idea where I can get a bulgin plug for it?

If the rest of it works ok I’m probably going to build a modern battery module for it

They are still made, avoid the low voltage only crap versions, that eBay dealers are ripping people off with, they need quite thin mains cable too.

Geo-blocking by ePay may prevent some UK listings from showing.

The smallest size is still made, Mouser, RS & Farnell have both PX0646 (straight) or PX0430/SE (right angle), these both have cable grips.
Avoid old stock as they are made from quite brittle plastic and avoid the low-voltage version that can be undone without tools.

The larger size is no longer made AFAIK, I have seen a right angle version with cord grip too.
These are used in some old audio gear and fetch high prices as a result.

Thought these would be useful for future reference, from the 1984 RS components catalog, it gives some sizes and the voltage ratings of those Bulgin connectors.
Note: that those with the cover that can be removed without tools, are only rated for 50V unless inaccessible  as shown by the * before the stock number.

Above quote from here https://www.eevblog.com/forum/buysellwanted/wtb-(nz)-3-pin-bulgin-conector/msg3796385/#msg3796385

David

[bd139]

Perfect. Many thanks 

[themadhippy]

Any idea where I can get a bulgin plug for it?

If all other routes fail try your local theatrical supplier as there the almost standard connector used on  pyro equipment.

[Vince]

Was about to put my breadboard back into its drawer now I am done designing the Fridge Timer (tm).

Then this breadboard reminded me how crap it was : the binding posts all came lose, came off the board ! 

The small 3mm screw at the back that keeps the center piece in place while you loosen the post with your fingers well.. even finger force is way more than than is required to dismantle the assembly and for it to come off the board. In short : it's unusable out of the box. Well nothing knew here. I bought it 5 years ago from Farnell, got the cheapest one they had because money, thinking Farnell wold not dare selling stuff that's so crap that it's unusable., for fear of ruining their reputation in front of their high paying professional customers. How naive that was.... straight out of the box, first use, these binding posts sucked and would not hold together, truly horrifying design and build quality.

Body is made of plastic, but very, very crap / soft plastic. The larger retainer nut at the back, that hold the outer part to the board, is very thin, nit much thread to bite with, and the thread is cut into the plastic body of the post. Since it's crap plastic... you can't really tighten the nut as much as you would want to otherwise the risk of ruining the threaded plastic body is guaranteed.

So I had to find new 3mm nuts for 3 of the 4 posts as they had again vanished, unscrewing themselves at the slightest action of your fingers on the posts.

So I decided to try to improve the fixation... looked into my junk box of Misc small H/W bits and bobs, and found x4 3mm star washers. Put them before the nuts, good twist of the wrench and .... wow, what a world of a difference that made ! Posts are now very well secured, I can undo them and the posts stays in place now, doesn't want to come off of the board. Victory. A small one, but one I appreciate...

I need decent quality binding posts. If any one know of a source with a decent quality for a reasonable price. Like not 10 Euros a piece, that would be good.
Decent quality plastic, and metal thread at the back not plastic. Availability in various colours would be cool as well. Having all black bindings posts on the board is not very easy to tell what's what.

Once I find a decent source for them, might stock a bit on them as these things are useful aren't they...


Now trying to decide on how best to organize all my freshly sorted transistors, to make the best use of space, yet make it easy enough to  find something when I need it. It's a trade-off...

[BU508A]

I'm having those. They are good for average use cases.

https://de.aliexpress.com/item/1005003057089177.html



Or get those Hirschmann PKI 10A:

https://www.ebay.de/itm/202101750679



5 black ones and 5 red ones:



As always: NAWTS

[Robert763]

So my DD haul was:

1/ Tektronix P6046 differential probe in the case with amplifier, PSU (115V) attenuator tip condoms £10 
2/ HP3466A £20 needs a couple of switc caps but I have some in stock. Naice that it is 4.5 digit and has "20" ranges
3/ Racal Dana 4009 A.K.A TTI 1905A computing 5.5 digit DMM. £15
4/ A box of "probes" £15. This inculded a Tek P2021 current probe with terminator    a spare P4046 several HP and TEK scope probes, older, but some unused. also some cheap Coline probes. I flipped 4 of those for £10 before I left.
5/ Time 1049 PT100 simulator (part of a deal, say £20)
6/ NI PCI GPIB card NIB £10
7/ NI ISA GPIB card £10 including "free" industrial 19" PC with a couple of mystery I/O cards and a Garmin GPS II
( @Vince , were you looking for one of these ISA GPIB cards)
8/ Weir 0-13V AC 0-17V DC power supply (0.7A variac + mains transformer and rectifier) £2
9/ Two odd AC "amplifiers". Custom made. each with a mains toroid DC supply, ILP 25W power amp module with 10T pot on input. One then has a back to front current transforme on the output with two taps 0-1A and 0-5A output. The other has a custom transformer woth 0-150V, 0-300V and 0-600V taps. Probably used as a calibration source well worth £20 the pair even for bits.
11/ Victoreen (Fluke) 440RF/D part of a trade basically profit.
12/ Box of Fluke temeperature (type K) interfaces and probes and two Fluke 80J10 10A 0.25% shunts. Need to sort through the probes £5
13/ Data Translation DT3000 16 channel 100kHz ADC + DAc PCI card with leads and two nice BNC breakout boxes. £5.
14/ Two L1000 "low delay video encoders". 1u  half rack box with LCD on front, BNCs, 9 D and filtered IEC inlet on back. £0 (free). Picked up for parts but these may have some value. Video ot SDI in MPEG data, ASI and 70MHz baseband out.
Also met some friends and had a chat. Overall a good day.

[bd139]

You were on to a winner there. Annoyingly I walked past all that before you even got there 

Anyway, HP 427A has had a light clean and inspection as I've got SFA to do:

Good specimen:



Battery, which I can't get out at the moment because I packed the pliers away. Sure it'll be fine for another 3 months considering it's nearly as old as me



One side:



Other side with crusty trimmer. Will brush it off carefully and check the damage in future.



Inside:



Problems to solve:

1. Dirt
2. Crusty trimpots
3. No mains cable
4. Test and calibrate