Test Equipment Anonymous (TEA) group therapy thread

[GregDunn]

That’s ok top of the 33oC here today (91.4oF) and the 38oC (100.4oF) tomorrow. Highest recorded temp here ever was 38.5oC 

Tends to reduce the average age of the population this weather 

The highest temp that was recorded here was 104 F (40 C) I think in 1933.

I spent a couple of weeks in Ridgecrest, CA (China Lake NWC) on a work assignment some time back; the average daily temp was about 39C (102F) and we did a day trip down to Edwards AFB where the temp was 41C (about 106F).  It was honestly less uncomfortable than a day here in the midwest at 95F; the humidity makes a huge difference.  Of course, out there I had to drink about a quart of water an hour in order to keep from dehydrating!  But as long as you stayed out of direct sun or wore some sort of cover and sunblock, it was OK for hours at a time - even on the flight line where that heat was reflected right back up at you.

The really interesting thing is that evaporative coolers were installed on the buildings everywhere and they did a great job thanks to that low humidity.  Our BOQ rooms stayed in the 70s with no need for any compressor-based air conditioning.

[factory]

As promised, here's a few pictures of the PM6603's innards.

And it sure isn't a Philips machine. They did not use Philips headed screws.

Underside:


This is much nicer than I'd thought.

Very nice and even more crammed inside than the multimeter I have.
Nearest Takeda Riken counter I can find is the six digit TR5014, the screws will be JIS and they have a little dot to indicate this.

PM 2423 Manual

Thanks, even if I don't have that DMM. It may be of Japanese origin, but the schematics are absolutely genuine Philips! Did they redraw them?

I should have said I have the dead tree format manual for PM2423, but it's nice to know a pdf is out there. 
It's definitely Japanese, the boards are labelled Takeda Riken Tokyo Japan.

David

[factory]

Hello TEA,

I hope, you can help me with a thing that confuses me.

A few months ago I have bought a nice HP 3456A.

Here are some pictures of it:

[snip]

A funny thingie, no idea what this is, looks like a wirewound resistor:



Thanks for your answers.

Mounty

I'm surprised no-one has answered what the mystery thingie is, it's an expensive looking reed relay for switching the input, rated at 1200V.
https://www.lintechcomponents.com/product/011355098/04901238/28480

David

[mnementh]

We knew you’d be along in a minute to save us all that thinking. 

mnem
*agitating-ily*

[factory]

Finally some time for TEA indulgence.  At a hamfest a few months back, I found a B+K 501A curve tracer. The seller had no idea if it worked and gave it to me for twenty-five bucks.  I put it on the shelf when I got home, lured by the siren call of some of the more complex gear in the repair queue. I pulled it out tonight to see if it worked (and if I could remember how to set up a scope in XY mode)...



[snip}

I am going to snuggle with the manual and get reacquainted with how these things work. After I do that, I will decide if I want to tear it completely down, and check to see if all the parts are still in tolerance given that the caps and carbon comp resistors are, I dunno, forty-five years old. 

Oh, one neat feature... the 501A has two sets of sockets so you can match transistors, whether of the same type or complementary.  And the sweep voltage goes up to 100V, so it will handle power transistors.

That was a very good price, I paid quite a lot more for my Heathkit IT-1121.
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg1766804/#msg1766804

Very handy for testing/comparing old obsolete components to find more readily available ones, also great for checking unusual parts such as tunnel diodes.

David

P.S. I'm curious to see what is inside the Leader LTC-905, which is the only other small vintage curve tracer I've seen for sale in the UK.

[bd139]

My HM203 has a rudimentary curve tracer built in. It's rather neat actually:

6.2v zener:



Even though this is a 20MHz crate it's a pretty nice scope. Am considering a HM1004 if I can get one.

[Johnny10]

The B&K 501A has a particularly good manual.
This was my first curve tracer and I set it up with a 2465A.

[mnementh]

mnem
"Weeth seex joo get egg loll..."

[worsthorse]

Finally some time for TEA indulgence.  At a hamfest a few months back, I found a B+K 501A curve tracer. The seller had no idea if it worked and gave it to me for twenty-five bucks.  I put it on the shelf when I got home, lured by the siren call of some of the more complex gear in the repair queue. I pulled it out tonight to see if it worked (and if I could remember how to set up a scope in XY mode)...



[snip}

I am going to snuggle with the manual and get reacquainted with how these things work. After I do that, I will decide if I want to tear it completely down, and check to see if all the parts are still in tolerance given that the caps and carbon comp resistors are, I dunno, forty-five years old. 

Oh, one neat feature... the 501A has two sets of sockets so you can match transistors, whether of the same type or complementary.  And the sweep voltage goes up to 100V, so it will handle power transistors.

That was a very good price, I paid quite a lot more for my Heathkit IT-1121.
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg1766804/#msg1766804

Very handy for testing/comparing old obsolete components to find more readily available ones, also great for checking unusual parts such as tunnel diodes.

David

P.S. I'm curious to see what is inside the Leader LTC-905, which is the only other small vintage curve tracer I've seen for sale in the UK.

My favorite non-production curve tracer is the Heathkit IT-3121, which often goes for way more than I am willing to pay on ebay.  Truth be told, no one uses this gear any more unless they are, like me, building stuff using largely obsolete discrete components. Even then it is more of a curiosity then a must-have piece of test gear.

That said, me and my 80s-electronics-nostalgia are going to wander down to my bench, hook the 501A up, and re-teach ourselves how to properly use a curve tracer.

[bd139]

For no reason other than to play with it, I dug out all my analogue gear and chucked it on the bench this evening. Rigols and TTi's in the cupboard.



The only "outlier" is the 8012A which is most certainly not analogue but I am devoid of an HP 427A at the moment   The other two HP power supplies are on the floor where they cant fall and kill me 

Think I need an HP analogue scope. Not a 1740A sized one though as it'd murder that shelf which already looks like it's slightly unhappy with all that glory on it.

Edit: and before tggzzz complains about the breadboard and poor probe grounding that board is well decoupled and running at ~2Hz max

Edit 2: any other HP gear suggestions, please let me know.

[med6753]

Think I need an HP analogue scope. Not a 1740A sized one though as it'd murder that shelf which already looks like it's slightly unhappy with all that glory on it.

You kill me. 

[med6753]

Here you go....but you better brace up that shelf. 

[bd139]

And the floor! 

[worsthorse]

For no reason other than to play with it, I dug out all my analogue gear and chucked it on the bench this evening. Rigols and TTi's in the cupboard.



The only "outlier" is the 8012A which is most certainly not analogue but I am devoid of an HP 427A at the moment   The other two HP power supplies are on the floor where they cant fall and kill me 

Think I need an HP analogue scope. Not a 1740A sized one though as it'd murder that shelf which already looks like it's slightly unhappy with all that glory on it.

Edit: and before tggzzz complains about the breadboard and poor probe grounding that board is well decoupled and running at ~2Hz max

Edit 2: any other HP gear suggestions, please let me know.

You get bonus points for having a beat up paperback copy of art of electronics placed oh-so-casually off to the side of your desk. 

[bd139]

Was actually using that. Can never remember how to build triangle oscillators . I’ve got 3rd edition as well but it’s less convenient to casually refer to. I’ve had that 1st edition copy I think since 1988

The RPN calculator is however taunting those afflicted with an equals button 

[BU508A]

Follow-up HP 3456A

So, this is my second try, hopefully I'll find this time the correct crystal.   

I've opened the bottom and removed the black aluminium shielding.

Yes, there it is:



But what is this? What is this strange angle of the board?   



Somebody had removed the board and did not put it back correctly. 

I installed the board correctly. Much better this way.

I've measured the signal on TP 1 before I'm going to replace the crystal.



Crystal replaced, checking again the signal. It is a bit stronger now.



I've put the original crystal in a plastic bag and stuffed it in a free corner of the 3456A.
Just in case.

Ok, let's do some measurements.

First, my 10kOhm 4-wire self-made calibration resistor:



Spot on! 

Now checking with the 5V voltage standard from Mr. Malone:



Not so bad. 

I'll leave it alone for now until my 7510 is coming back from calibration.
Will do then some comparison and hopefully no adjustment is needed.

And, last but not least, I've found the little brother of El Capo:

 

[Neomys Sapiens]

Agreed, but I don't have much use for a probe with a 31ohm input impedance (10pF@500MHz), especially when you include the inductance of a ground lead.

At those frequencies I prefer a 500ohm 1pF resistive divider probe. Bonus: you can make those yourself by soldering a 450ohm resistor to the board and 50ohm cable

Next time I'll consult the datasheet first. 

You are right, 10pf is way too much for a 500MHz probe. No idea what they are smoking at Testec ...

Even good passive "high" impedance probes are 6.5pF, and only for scopes with a 6-9pF input!

There are many probes like that Testec, from many manufacturers They have some utility when connected to the circuit directly, typically using bent paper clips:

Some fine bending and soldering. I'll have to revert to such methods too when the stash of P6139 sockets runs out, but fortunately I still got around 20.

[Neomys Sapiens]

Not so dumb as you think. The hot water is obviously borked, note missing handle and shaft. This means it's turned off at the other end. Now if you left that connected, anytime somebody set the washer to a "WARM" cycle, it would backflow and spray all over through the hole where the valve shaft on the hot water bibb used to be.

This at least gets the washer functional until you can get somebody out with the crimpers to repair that fucking demonic PEXX piping.

Fuckitol.... I guess those years spent working in the Ding & Dent Appliance warehouse DID teach me a thing or two of value... 

mnem
moo.

No, it's NOT borked. It was done intentionally. About 5 years ago when fuel oil prices spiked in order to save fuel and keep the price of using the washing machine in check the land lord disconnected the hot water. So the machine is cold water only. But he never told anyone that he did that I guess because he assumed that people would see very clearly that it's cold only. Now you know what happens when you assume. Obviously I saw it immediately and made adjustments to do my laundry in cold water. Not so the other dumb asses who live here. Do you know how many times I go to use the machine and it's set to warm or hot?  More than I can count. 

Is it normal for a washing machine in the US to use hot/warm water supplied by the building?
All of ours use a internal electric heater, therefore it was so easy to understand.
Although it gives me an idea for a mod, as my hot water supply is not metered.

[Neomys Sapiens]

As promised, here's a few pictures of the PM6603's innards.

And it sure isn't a Philips machine. They did not use Philips headed screws.

.
.

I almost fear to ask, but you are aware of
Philips ≠ Phillips?

[med6753]

Is it normal for a washing machine in the US to use hot/warm water supplied by the building?
All of ours use a internal electric heater, therefore it was so easy to understand.
Although it gives me an idea for a mod, as my hot water supply is not metered.

Yes, it's normal. "Point of Use" hot water heaters are rare in the U.S. Normal configuration is a central hot water heater which can vary from 25 to 50 gallons or so and they can operate from a variety of fuel sources such as fuel oil, natural gas, propane, or electric.

Now some of the newer high efficiency washers DO have internal water heaters but still rely on an external hot water source.

[nixiefreqq]

For no reason other than to play with it, I dug out all my analogue gear and chucked it on the bench this evening. Rigols and TTi's in the cupboard.



The only "outlier" is the 8012A which is most certainly not analogue but I am devoid of an HP 427A at the moment   The other two HP power supplies are on the floor where they cant fall and kill me 

Think I need an HP analogue scope. Not a 1740A sized one though as it'd murder that shelf which already looks like it's slightly unhappy with all that glory on it.

Edit: and before tggzzz complains about the breadboard and poor probe grounding that board is well decoupled and running at ~2Hz max

Edit 2: any other HP gear suggestions, please let me know.

SERENITY NOW!

[tggzzz]

For no reason other than to play with it, I dug out all my analogue gear and chucked it on the bench this evening. Rigols and TTi's in the cupboard.

The only "outlier" is the 8012A which is most certainly not analogue but I am devoid of an HP 427A at the moment   The other two HP power supplies are on the floor where they cant fall and kill me 

Think I need an HP analogue scope. Not a 1740A sized one though as it'd murder that shelf which already looks like it's slightly unhappy with all that glory on it.

Edit: and before tggzzz complains about the breadboard and poor probe grounding that board is well decoupled and running at ~2Hz max

Edit 2: any other HP gear suggestions, please let me know.

All your analogue kit? How deprived you must be feeling

Major problem with big PSUs is that you ought to wear toetectors. In the 70s I had an enormous 5V switching PSU. The switching was done by SCRs at 50Hz!

I like my 1740A as much as the 465; the screen is nice and big, but that means the case is too big.

Other HP gear? I've just got a pulse injector which might be useful; it came with a Testec 40kV DVM probe.

And looking out my back window 30mins ago there was the best electrical storm I can remember seeing, 15 miles away over Bath. I could see 1-4 strikes/second sustained. Don't know if it was raining or whether the lightning bothered to hit the ground - all I could see was the cloud being diffusely illuminated.

[mnementh]

Is it normal for a washing machine in the US to use hot/warm water supplied by the building?
All of ours use a internal electric heater, therefore it was so easy to understand.
Although it gives me an idea for a mod, as my hot water supply is not metered.

Yes, it's normal. "Point of Use" hot water heaters are rare in the U.S. Normal configuration is a central hot water heater which can vary from 25 to 50 gallons or so and they can operate from a variety of fuel sources such as fuel oil, natural gas, propane, or electric.

Now some of the newer high efficiency washers DO have internal water heaters but still rely on an external hot water source.

"Demand water heaters" are becoming more and more common in new construction. The "new business" model means every square foot is weighed for profitability with the fewest man-hours maintenance over life; this returns the space once used for "utility closets" to profitable square footage, and as it makes use of what used to be "dead space" under sinks, it becomes better to let the lessor pay their hot water cost directly rather than pay a third party to calculate and prorate said cost and another third party to maintain a central source. Particularly in commercial spaces, this is part of the new "modular construction". I've seen what must've been a hundred of them being deployed in a single building while doing infrastructure work; dozens of contractors placing and pulling the wiring at the same time while the drywall was still on pallets.

mnem
Yes, but do we REALLY need eight cat6 drops in a lavatory?

[Kosmic]

I was on the lookout for some good probes to go with my Lecroy scope. Received those today (1Ghz, 1.8pF). They unfortunately did not comes with the accessories. But since I paid around 20$ each, I’m not going to complain 

[bitseeker]

$20!