Test Equipment Anonymous (TEA) : Discussion and Group Therapy Thread

[mnementh]

Dad Update:

They moved him into ER Observation during the night... Discharge coordinator is saying he is within an applicable window for readmission to the facility where he was for PT, and to my shock & amazement, they actually have gotten someone at the facility, and they claim to have a bed for him. He may be admitted there as soon as this afternoon.

I'm currently battling carburetors and lawncare.

mnem
effing ow.

[Cubdriver]

At least a sliver of good news re your dad - glad to hear.

-Pat

[Specmaster]

Thanks for the Dad updates and best wishes from me as well. If that idiot had 87A on his shirt, I'd have said he was destined to be joining your dad in 4 more beds further along the line in the hall. Is that a proper hall as in a big room, or is it like a corridor?

[mnementh]

Just got back from visiting dad at the post-op Rehab Center. He's annoyed with all the hassle; but his PT people have already seen him, and had him walk a dozen steps or so. This is already better than he was a week after the first fall.

mnem
I'm gonna piss off and have some dinner now.

[mnementh]

Thanks for the Dad updates and best wishes from me as well. If that idiot had 87A on his shirt, I'd have said he was destined to be joining your dad in 4 more beds further along the line in the hall. Is that a proper hall as in a big room, or is it like a corridor?

No; when I said hallway, I meant they had his bed parked in a fucking hallway. Along with aboot 30-something other beds I passed in various hallways on the way there.

mnem
This is the state of medicine in America.

[tggzzz]

This is the state of medicine in America.

We are catching down

[bd139]

Hey we don't have Catholic hospitals yet!

[tggzzz]

Hey we don't have Catholic hospitals yet!

Religious schools are enough

And that's as far down that rathole as I'm prepared to go!

[synx508]

I've been having fun with the Wavetek 278 today. This morning I needed a waveform for something so I thought I'd give it a try and it seemed to start up normally but refused to produce any output so I thought I'd investigate and maybe uncover the mystery of "output protection on" along the way. Anyway, first stop was the 6,800µF 16V smoothing capacitor on the 5V supply. It was running warm after a few minutes of operation and had a bulging top, so I decided it had to go. I didn't have anything similar so I filed down the pins of a snap-in 10,000µF 25V and that fitted nicely. After cleaning up the flux I spotted this.



This was not good, so I removed a lot of solder on the connectors and rectifier and replaced it with new solder. Then I reassembled, which involved cleaning up a row of voltage regulators and giving them fresh heatsink compound. It works properly now and I was celebrating the lack of "output protection" to the point I thought I'd post here - at which point it issued the terrifying beeps of doom. So I've brought it back, but not solved its particular quirk

I suspect this strange error is related to the unacceptable DC offset on the output, which I'll have a look at tomorrow.

[bd139]

That is what killed an HP 1740 I had ages ago.

Gore here: https://www.eevblog.com/forum/testgear/ ... y-burn-up/

[synx508]

That is what killed an HP 1740 I had ages ago.

Gore here: https://www.eevblog.com/forum/testgear/ ... y-burn-up/

I have been reading that recently!

By coincidence I have a 1742A that I've mostly sorted, but it has loads of HV osc ripple on the HV PSU. I don't have enough division/HV capability in any of my probes so I'm sort of in the dark over what the fault could be, though I expect it's a capacitor. I have most of a 1740A that looks to have been refurbed by HP in around 1993/4 which has what appears to be a much newer HV PSU and I'm thinking of just swapping that and the gate board over. The 1740A has a gently roasted Molex too, with the PCB around the rectifiers looking like charcoal. The vertical output board is also quite dark.

[Zenith]

Can you replace its own power supply arrangements, at least in part, with a bench power supply or two? it might involve some codging, but it can save a lot of hassle. From the manual it looks as if it needs +45, + and - 15 and +5.

It could be a hardware problem, but since this is microprocessor controlled it could be something like a corrupt ROM or maybe a relay not working.

Just some general, and maybe not that useful, ideas. At least the manual seems at first glance to be quite detailed, which is more than can be said for a lot of microprocessor based equipment.

[synx508]

Can you replace its own power supply arrangements, at least in part, with a bench power supply or two? it might involve some codging, but it can save a lot of hassle. From the manual it looks as if it needs +45, + and - 15 and +5.

It could be a hardware problem, but since this is microprocessor controlled it could be something like a corrupt ROM or maybe a relay not working.

Just some general, and maybe not that useful, ideas. At least the manual seems at first glance to be quite detailed, which is more than can be said for a lot of microprocessor based equipment.

I think the supplies are fine now but I've not done a full set of measurements. From wire wiggling I deduced that I needed to do more taking apart. I've found more solder joints that have failed on the analogue board which has also had the output amplifier repaired at some point. The manual is indeed excellent and the internal wiring doesn't require me to do anything too painful to pull boards out to inspect them, which is nice.

[Cerebus]

Hey we don't have Catholic hospitals yet!

With nuns wandering the corridors. Give me vampires, zombies, ghouls, but not nuns.

[vk6zgo]

Hey we don't have Catholic hospitals yet!

With nuns wandering the corridors. Give me vampires, zombies, ghouls, but not nuns.

We still have Catholic hospitals in Oz, but the nuns have pretty much disappeared.
They don't look any different to Govt hospitals, except for the names.

Interesting anecdote-------years ago, when my Mum went to "St John of God", the process of "de-nunification" was already well established, but there was a "Unicorn" there----an Anglican nun (betcha didn't know they existed) who visited people of that persuasion, which (nominally) Mum was.
Mum remembered the same nun from many years before, so she must have been of an advanced age at the time.

[bd139]

Hey we don't have Catholic hospitals yet!

With nuns wandering the corridors. Give me vampires, zombies, ghouls, but not nuns.

What about rubber nuns. I’d go for them.

[tggzzz]

Hey we don't have Catholic hospitals yet!

With nuns wandering the corridors. Give me vampires, zombies, ghouls, but not nuns.

What about rubber nuns. I’d go for them.

The evidence from Ireland (maybe elsewhere) is that they "go" for those in their charge. Sinead O'Connor was famously vocal about that.

I, at least, had decided not to raise the spectre of latex. No, that is not a prompt for certain other ill-remembered pictures.

[nixiefreqq]

With nuns wandering the corridors. Give me vampires, zombies, ghouls, but not nuns.

What about rubber nuns. I’d go for them.

The evidence from Ireland (maybe elsewhere) is that they "go" for those in their charge. Sinead O'Connor was famously vocal about that.

I, at least, had decided not to raise the spectre of latex. No, that is not a prompt for certain other ill-remembered pictures.

graduated from high school with a tall slender girl who i almost asked out later when we were attending different colleges, but used to sometimes run into each other at the public library. but she was really too tall and too smart for a dumb bumpkin like me. she became a nun and is now the president of a catholic university. (she probably thought i was catholic too....but nope. so it would have never worked out anyway).

never heard of a "rubber nun". went to the googles.....maybe i need to get out more?

[synx508]

Latest and likely final Wavetek 278 update, I have eliminated the spurious output protection alarm, this was down to the analogue board (referred to as the function generator in the manual) having bad joints on every pin of its Molex power connector *and* having many variable resistors in very much the wrong place. I followed the step by step calibration process in the manual and it's fine now. Sine distortion went from 3.5% to 0.27%.

About that calibration and alignment process, though…

Each step in the process has its own ROM based preset. You enter the code (1000+step number) and it configures itself appropriately, which is nice. What's really nice is it also displays the name of the alignment step and the component identifier of the tweakable you need to tweak. You could almost do it without the manual as most of the target values are obvious. A few aren't, like aiming to set something to output 999Hz instead of 1000Hz, I suppose if they'd had a bigger screen they could've included all the information.

The only thing I didn't enjoy about this process was the choice of values of some variable resistors. They're a good brand but only single turn and several are really knife-edge settings as there's a very broad range of adjustment, they've definitely got the gearing wrong on a few of them. Going to look out for other Wavetek gear of a similar age now, I think I'd been a bit of a snob about it previously.

[bd139]

Sounds like setting up a TTi function generator. Some multiturns would be good in them!

[Robert]

Latest and likely final Wavetek 278 update, I have eliminated the spurious output protection alarm, this was down to the analogue board (referred to as the function generator in the manual) having bad joints on every pin of its Molex power connector *and* having many variable resistors in very much the wrong place. I followed the step by step calibration process in the manual and it's fine now. Sine distortion went from 3.5% to 0.27%.

About that calibration and alignment process, though…

Each step in the process has its own ROM based preset. You enter the code (1000+step number) and it configures itself appropriately, which is nice. What's really nice is it also displays the name of the alignment step and the component identifier of the tweakable you need to tweak. You could almost do it without the manual as most of the target values are obvious. A few aren't, like aiming to set something to output 999Hz instead of 1000Hz, I suppose if they'd had a bigger screen they could've included all the information.

The only thing I didn't enjoy about this process was the choice of values of some variable resistors. They're a good brand but only single turn and several are really knife-edge settings as there's a very broad range of adjustment, they've definitely got the gearing wrong on a few of them. Going to look out for other Wavetek gear of a similar age now, I think I'd been a bit of a snob about it previously.

Glad you got some entertainment from it....

[Cerebus]

Hey we don't have Catholic hospitals yet!

With nuns wandering the corridors. Give me vampires, zombies, ghouls, but not nuns.

What about rubber nuns. I’d go for them.

You're looking for the "Sisters of Perpetual Indulgence". First convent on the left in Old Compton Street.

[bd139]

With nuns wandering the corridors. Give me vampires, zombies, ghouls, but not nuns.

What about rubber nuns. I’d go for them.

You're looking for the "Sisters of Perpetual Indulgence". First convent on the left in Old Compton Street.

I've dated worse

[mnementh]

So have they. *looks askance at Cerebus*

mnem

[AVGresponding]

Hey we don't have Catholic hospitals yet!

With nuns wandering the corridors. Give me vampires, zombies, ghouls, but not nuns.

[youtube]https://youtu.be/MpLZBYDaZI8[/youtube]

PS I hate this shitty UI as much as the one in Discord