Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

...So it's got a Tek 465 tube in it, it isn't made directly by Tek but a Tek subsidiary. Did I violate the no more Tek 4xx series scopes rule? Nope! 

Yeah, but you did swear off Telequip as well... I understand your mother was the cause of that, but still recidivism.

mnem
*currently trying to design a part for my new case on my laptop*

[Saskia]

You guys are crazy

@Brumby




 *gnihihihihi*

[tautech]

2. Intensity is really badly set up. Need some recal on that. At lowest intensity it's pretty bright and you can see the flyback even though z blanking is mostly working

Likely the intensity bias is all up the wack from the high MOhm carbon resistors drifted all over the place.
Replaced them all in my D83, adjusted the EHT and then the bias preset as per normal so you can just lose the trace at min intensity levels and that part for one never gave problems again. 

[mansaxel]

The swedish system is:

Digit	Pulses
0	1
1	2
2	3

...et cetera up to 9.

But this would mean, that on the old phone with the dialing scale it goes like 0, 1, 2, ... 9 and not as in Germany from 1, 2, 3, ... 9, 0

Example: the famous W48

Exactly! And this is the BC560 -- you can plainly see that its man-machine interface is set up for the most logical translation of human understanding of mathematics into electrical information.

[med6753]

got this morning a message from Mouser that my order has been processed and will be delivered. ETA: Monday.

Yea, I got a msg that mine is projected to ship today. But the bummer is I paid for UPS 2nd day air but UPS does not deliver on weekends. So it should show up Monday.

Very bad timing. Happens often these days. 

I want to give them the benefit of the doubt. I suspect that perhaps they were still badly backlogged on some big corporate accounts that they need to clear first. They have spoiled me over the years. Whenever I ordered on a weekend that Monday it ships. And if I order early on a weekday it ships the same day. So waiting a week for an order to ship is definitely not the norm. I'll see what happens at the end of this month when I order parts for the Type 422. I would figure any backlog should be cleared by then.   

Just got a msg that it has shipped.

[bd139]

Ok full evaluation of the D755 has taken place. Took over an hour to edge through it all. Project commencing! To do:

1. Need to find a replacement for the mains socket that fits in a 1 3/8" x 1/2" hole (suggestions welcome!)
2. Transformer needs screwing down hard
3. The astig pot on the back is missing the shaft so needs replacement. It can be driven with a screwdriver but it's inconvenient. Fortunately only 100V across 100K for that.
4. The main A timebase knob is a replacement one and is completely wrong. Will find a better one or an original one.
5. Main power supply filter caps have leaked a bit. They fortunately dripped down into the chassis so there's a couple of rust spots on the outer case and no board damage (phew!)
6. Various horrible looking electrolytics dotted around the unit. So 24 electrolytics to replace in total.
7. Couple of trimmers where the plasticiser has crept out need cleaning and exercising.

Going to do a "modular refurb" so will pick up all parts in one go then recap and retest each module, then cal it, burn it in, check cal and job done.

Fun ahead 

[bd139]

2. Intensity is really badly set up. Need some recal on that. At lowest intensity it's pretty bright and you can see the flyback even though z blanking is mostly working

Likely the intensity bias is all up the wack from the high MOhm carbon resistors drifted all over the place.
Replaced them all in my D83, adjusted the EHT and then the bias preset as per normal so you can just lose the trace at min intensity levels and that part for one never gave problems again. 

This one appears to be a fairly late one. All the resistors are VR series ones so not drifted. I think the previous owner has been "at it" as there's some sign that the cal has been futzed with on the trimmers. I get the feeling he didn't follow the cal instructions.

[tautech]

2. Intensity is really badly set up. Need some recal on that. At lowest intensity it's pretty bright and you can see the flyback even though z blanking is mostly working

Likely the intensity bias is all up the wack from the high MOhm carbon resistors drifted all over the place.
Replaced them all in my D83, adjusted the EHT and then the bias preset as per normal so you can just lose the trace at min intensity levels and that part for one never gave problems again. 

This one appears to be a fairly late one. All the resistors are VR series ones so not drifted. I think the previous owner has been "at it" as there's some sign that the cal has been futzed with on the trimmers. I get the feeling he didn't follow the cal instructions.

OK then to prove the point set up the Intensity correctly as it takes just a few minutes .......before you order the other stuff.

[bd139]

Yeah I did that - sorry forgot to mention that 

[Robert763]

Ok full evaluation of the D755 has taken place. Took over an hour to edge through it all. Project commencing! To do:

1. Need to find a replacement for the mains socket that fits in a 1 3/8" x 1/2" hole (suggestions welcome!)
2. Transformer needs screwing down hard
3. The astig pot on the back is missing the shaft so needs replacement. It can be driven with a screwdriver but it's inconvenient. Fortunately only 100V across 100K for that.
4. The main A timebase knob is a replacement one and is completely wrong. Will find a better one or an original one.
5. Main power supply filter caps have leaked a bit. They fortunately dripped down into the chassis so there's a couple of rust spots on the outer case and no board damage (phew!)
6. Various horrible looking electrolytics dotted around the unit. So 24 electrolytics to replace in total.
7. Couple of trimmers where the plasticiser has crept out need cleaning and exercising.

Going to do a "modular refurb" so will pick up all parts in one go then recap and retest each module, then cal it, burn it in, check cal and job done.

Fun ahead 

For the socket try a C6 lke this
http://www.farnell.com/datasheets/2612243.pdf

[med6753]

So I'm watching TV and had scanner on mute. I hear an explosion. I look outside and see this. Car fully involved in flames. They were driving down our road. Car started smoking. He pulled into our parking area and car burst into flames. Driver got out and is OK. My CR-V was parked in front of that garage. Quickly moved it. FD arrived and put it out they are currently cleaning up.

Figures....a call to MY residence and I don't hear it. 

[mansaxel]

Ok full evaluation of the D755 has taken place. Took over an hour to edge through it all. Project commencing! To do:

1. Need to find a replacement for the mains socket that fits in a 1 3/8" x 1/2" hole (suggestions welcome!)

There are a bunch of people replacing that horrible oval mains inlet on old -hp- gear, for which the matching cables are made of the purest Unobtanium, with "Mickey Mouse" IEC C6 inlets, more specifically Schurter 4300.0100, which can be found from several of the usual suppliers. Apparently only small amounts of hole enlargement are needed to fit it in place of the US inlet.

Edit: What Robert said. We apparently agree!

[bd139]

Robert763/mansaxel: Unfortunately C6 is too large for this one. There's very little room for anything to be honest.

Here's what I've got to work with. I am thinking of adding a plate and a captive lead as there's a cable winder on the back. As much as I hate captive leads it might be the best solution here 

Edit: all parts for refurb / repair ordered. I've made some compromises on axial vs radial caps in a couple of places and some values are higher but they are all non critical parts. Also will have to parallel a couple of elecs for one as the original part is completely unobtanium. Total spend £13.22 from bitsbox inc delivery. Mostly panasonic caps as well 

[mnementh]

Boring Mundane Everyday Interesting Fun Project Print #772: Bracket for Matrexx 70 Computer Case

For those who care: Details are here in the 3DP thread.

mnem

[BU508A]

Dear TEA-fellownuts,

today (Friday) the Power Desingns Model 2005A showed up at my doorstep.
I have promised to do a teardown and here we go: 

The package was not stellar but okay. It arrived undamaged at first sight.
This is the front. Looks nice and clean.



Backside the same, nice and clean. Someone has crossed out the 125VAC remark. 


Let's have a closer look inside. Left picture is an overview, the red circle is the top of the oven. Middle picture shows more details of the wiring. The board does not have any traces on it. The picture on the right shows a side view of the oven (sorry, it is a bit blurring).




From left to right: mains input with fuse, transformer with some suspicious looking capacitors, outputs backside with capacitors



Left to right: Rotary switches with some precision resistors, another viewing angle to the rotary switches and the binding posts for the frontside outputs with some capacitors from Sprague



Left to right: the slot for the access to the cal- and zero-trimpots, the trimpots itself and a sideview of the instrument, made by General Electric



Left to right:
Some Sprague capacitors (the date codes suggests, that this 2005A has been built around 1970/71), Sprague capacitors and the wiring to the NPN power transistor for the linear regulation, the power transistor Q5 itself (Motorola MS1700, NPN-type, no idea, what this 6-36 means)



This is a hi-res picture of the bottomside of the board. Isn't it gorgeous?



Here are some details of the board and more datecodes from 1969. The fuse looks like the very first one which never got replaced.




But is it working? Let's find out ...
I've connected it to my Keithley DMM7510 because I wanted to see how it behaves when switched on.
I've set the 2005A to 10V and it seems, it is ca. 3mV off. But let's see how it will drift.



Left to right: Some more measurement after ca. 2h uptime, The two pictures to the left are showing the complete plot so far. The overshoot can be seen very nicely and it seems it want to settle somewhere around 9.997200V (actually it shows 9.997238V). There are also some spikes downwards, no idea actually where they are coming from. Will observe this further. The two pictures to the right are showing the details of these spikes. There are also some spikes upwards. My guess is: they are caused when the heater of the oven gets switched on. will check this as well.



Edit:
Forgot to show some statistics and the settings of the meter:



The contacts of the rotary switches need some cleaning and the switch for the 10mV range is hard to rotate - need some cleaning and lubrication but besides from that all the knobs, verniers and switches are working very nice.

I do like this 2005A and I'm happy that I got one which can be directly connected to 230VAC. 

Thanks for watching, I hope, you've enjoyed this teardown. 

[nikodem]

Is this test equipment? Definetely it's lab equipment! PCO FlashCam - ultrafast (for it's time) CCD camera with digital interface (duh, Centronics).





I have miraculously found some software (thanks to vacuum hax0rs Discord server users) and plan to test it tomorrow. Anyone interested in a teardown?

[med6753]

......snip


Left to right: Some more measurement after ca. 2h uptime, The two pictures to the left are showing the complete plot so far. The overshoot can be seen very nicely and it seems it want to settle somewhere around 9.997200V (actually it shows 9.997238V). There are also some spikes downwards, no idea actually where they are coming from. Will observe this further. The two pictures to the right are showing the details of these spikes. There are also some spikes upwards. My guess is: they are caused when the heater of the oven gets switched on. will check this as well.

Very nice! I've used those supplies in the past at work but don't own any. Now considering how minutely small those spikes are does it really matter? I don't think even the most sensitive equipment is going to even notice it.

[Brumby]

Now considering how minutely small those spikes are does it really matter? I don't think even the most sensitive equipment is going to even notice it.

The second you rely on that, Murphy will hand you that one-in-a-million situation when your day turns bad.

Edit:  On second thought, Murphy is more likely to lull you into a false sense of security for a while and then target a nice piece of unobtanium.

[Brumby]

I am truly humbled by the assistance offered by members here.  I am currently communicating with two people with an interest in helping me resolve my PC aspirations.

The EEVblog is a good place to be.   



(Yes, even with Bean and all you other enablers......)

[srb1954]

Trust the Swedes and New Zealanders to be difficult 
You learn something new every day.

I always thought that the dials on New Zealand telephones were more logical with the numbering increasing in the clockwise direction - everyone else in the world seemed to number their dials in reverse.

The NZ telephone system was essentially based on British equipment and used the same dial mechanisms in the phones. As a result the reverse ordering of the telephone dial numbers resulted in our emergency number being 111 rather 999 as in the British system.

[mansaxel]

Trust the Swedes and New Zealanders to be difficult 
You learn something new every day.

We're not difficult, just more logical. Computer agrees:

Code: [Select]

treize:tea mansaxel$ if [ 0 -lt 1 ] ; then printf "Swedish rotary dials are more logical\n"; fi
Swedish rotary dials are more logical
treize:tea mansaxel$


[beanflying]

Because Lasers are Cool  10mm EVA test cuts prior to box inserts being made.

[cyclin_al]

Fuck my life does anyone know how to package stuff?!?!!

Yup. The scope I sent arrived fine. There was a hole in the outer box, but that's why it was two three-wall boxes plus foam to protect the knobs plus bubble wrap plus bouncy foam rubber

Heavy, not cheap!

Just for the record, as a person who spent a few years as the factory maintenance engineer in a special packing company who made special shipping crates and cardboard boxes with dedicated foam packing inside them, that three wall cardboard boxes is called Tri-wall.

https://tri-wall.co.uk/

That's a little misleading as the generic term is "triple wall", although everyone in the industry calls it  triwall board, it's only really "Tri-Wall" if it's made by Tri-Wall (who used to be American, now they're Chinese).

And, as I've said before, the toughest cardboard cases you'll find are triwall all-flaps-meet cases made for shipping Whiskey and the like - blag from from your local off-license.

Cerebus, BOFH, Reed Corrugated Cases Ltd., 1985-1988.

Over here, Tri-wall was known to make good quality cardboard, and were the obvious selection for a box that matched the footprint of a pallet.
Nowadays, any cardboard box with footprint matched its attached pallet is known as a tri-wall, no matter the number of layers of cardboard wall or even if its plastic...

[Brumby]

Because Lasers are Cool  10mm EVA test cuts prior to box inserts being made.

     

Very cool ... and very nice.

[cyclin_al]

Oh, the apprentices had an eating battle today. Spoiler: the skinny guy won.



The food in question was flatcakes, in the case of the loser, he had a bacon egg sausage tomato and hash brown, the winner (or wiener, can't decide) is the technically-still-an-apprentice and he had a breakfast flatcake, which has bacon egg sausage tomato hash brown beans spam mushrooms.

Neither of them was particularly keen to do much exercise work afterwards...   

Ah, memories!  I remember now about 10 15 years ago having an apple pie eating contest on the loading dock at work for the Halloween party.  I handily won in 4:50 eating a full pie with lots of whip cream.  The following year, a lot of my co-workers were hyping it up.  The new new guy quietly went to work and finished a pumpkin pie with lots of whip cream in about 3:45.  Next day was a staff bicycle ride of approximately 160km to work it off    Those were fun days.