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Test Equipment Anonymous (TEA) group therapy thread

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mnementh:

--- Quote from: m k on July 05, 2022, 07:49:36 pm ---
--- Quote from: mnementh on July 05, 2022, 01:45:40 pm ---...Yeah, 625 line PAL is interlaced; I was thinking that when we were talking before.  :-+

That's another reason I decided to put a pin in this project; I'm waiting on the outcome of this eBay dispute. If I'm not keeping this turd, I think I'd much rather spend the time and brain power figuring out what went wrong with my fuckeroo UTG962E. And playing with my brand-new LeSiglent T3DSO2102.  :-DD

mnem
Never any shortage of things a tinkerdwagon needs to do...

--- End quote ---

I'm a bit interested how this scope thing finally is.
For now my guess is that this 313 vertical has nothing to do with PAL.

Is there possibly a military grade high resolution video system with small screens?
Just wondering from where HP got their idea.

Somebody should count those H-sync pulses.
625 is raw PAL and it includes blanking time.

Somebody should also adjust their scope monitor so that returning beam is visible and count how many H-lines it needs.
That much is needed over that 313.

Old Hitachi schematics has very clear horizontal timing as 41.2us.
Is it the right device for sure?

Only one google hit for CDU-10BA241, title of Hitachi schematics.
https://www.eevblog.com/forum/testgear/hp-871xb-vna-crt-module-capacitor-identification-help/

Much more for CDK-10BA242.
One of its CRT is 240ANB31N and earlier tube shuffle pays off.
As everybody remembers 31 is green, it continues so that 4 is white.
Tube in Hitachi schematics is 240ANB4(N).

Is this white CRT a rarity, is the whole input side of that schematics a rarity?
Maybe 546xx real H-sync is something else than 24270Hz.

--- End quote ---

According to the Wikipedia entry, there were several PAL standards; most operated at 625 lines(576 visible)50Hz while PAL M operated at 525 lines(480 Visible)60Hz. There was a "standard" called PAL-60 as well that allowed European VCRs to display NTSC VHS tapes; it was a bastard in that it misused the hardware by displaying PAL video at 60Hz with the NTSC color information, this was later promoted by video game consoles like the DreamCast.

I've read somewhere in the HP sales fluff that "waveform refresh" is at 60Hz, so I suspect it is something like that. OTOH, as they're using the PAL chip in a closed system, there's probably no reason they couldn't make their own "bastard" format at 625 lines(576 visible)60Hz...  :-//

As for where these monitors came from... they are small open-frame industrial monitors meant for all sorts of automated manufacturing applications; usually driven by some embedded computer.

mnem
I think. As always, take anything I say with a grain of salt big enough to pickle a dragon. ;)

Cerebus:

--- Quote from: mansaxel on July 05, 2022, 07:53:24 pm ---
--- Quote from: tggzzz on July 05, 2022, 05:12:52 pm ---The rest, not so much: a major benefit of going out is to inhabit somewhere completely different, not to stay in cyberspace.

--- End quote ---

The trick is to do Augmented Reality -- experience the Real World enhanced with information from Other Places. It makes the Real World a more multifaceted place. And it takes less time to immerse yourself into something when you can apply the aggregate previous knowledge of the world on top of the actual experience.  The most obvious example to me is GPS and electronic maps.

--- End quote ---

Pah! You can have my compass and Ordnance Survey 1:25000 maps when you can prise them out of my cold dead hands.

mnementh:

--- Quote from: Cerebus on July 05, 2022, 10:35:55 pm ---
--- Quote from: tggzzz on July 05, 2022, 10:08:49 pm ---
--- Quote from: Cerebus on July 05, 2022, 07:13:20 pm ---Roger Needham used to recommend that your passwords should be "shocking nonsense", the shocking bit intended to make you think twice before telling someone your password. On that basis perhaps one should use one's 11th digit, the middle wicket so to speak, so that you aren't tempted to reveal your *ahem* original biometric in public. Of course revocation would be particularly undesirable.

--- End quote ---

I can think of people for whom it would benefit mankind. Much like retrospective abortion.

--- End quote ---

I believe the term of art is "Elective post-partum termination".  >:D
--- End quote ---

"Enforced Darwin Award".

mnem
*toddles off to the dwagon cave*

med6753:
Let's see....am I in the right thread?  :-DD

Anyway, starting looking at this FUBAR'ed Type 1A1 plug-in. On the lower vertical settings (20mV, 10mV, 5mV) ranges there is considerable noise on the channel 1 trace. And the noise is still present when the input is set to GND position.



First suspects are FET's Q122 and Q142. Located on this little pre-amp board. I have spares from a parts Type 1A1. Changed them out and it took care of the excess noise. However, now the DC balance, gain, compensation for channel 1 are completely out the window and I'll have to re-calibrate Channel 1.





Once Channel 1 is re-calibrated then on to Channel 2. On the lower vertical settings the high frequency compensation is peaking and can't be adjusted out.

Vince:

--- Quote from: BU508A on July 05, 2022, 10:39:20 pm ---
--- Quote from: Vince on July 05, 2022, 10:31:12 pm ---First power it up to figure out which channel works and which one doesn't.
Then try to see within that channel, what component is dead... assuming I am lucky and it's one of those few big TH components, rather than one in a million tiny SMD components on the under side of the board.... with no schematic and board layout to help, I have zero chance of fixing this board....

--- End quote ---

I recommend to look out for the datasheet of the controller IC. The manufacturer are following often very closely the design recommendations given in the datasheets. Helped me in the past several times.

--- End quote ---

Just removed the rubbery goo that was covering the driver chip. 16 pin.

Hard to read, used the optivisor + torch light for 5 minutes, still not 100% sure what the P/N is.

I think it's :

 6N18665

However I am not sure about the two digits in red. Might be the letter ' G ' or digits ' 6 ' or ' 0 ', I can't get a reliable view on them.

It tried googling but no luck what so ever...

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