Test Equipment Anonymous (TEA) group therapy thread

[Kosmic]

I actually have a roll of Cat6A cable here that I wired my house in, but it is solid so not very flexible at all...
Maybe I should look for some stranded stuff. Is there any particular wiring method (Like keep the pairs connected only to themselves, or connect the white wires together, and the coloured wires together)?

Keep the twisted pairs together. If you remove them from the sleeve and use the pair individually will be easier to work with.

Also, like syau mentioned, if you are looking for low emf, drop the connectors and use freshly cut cables.

[tggzzz]

The +15V on the Sweep board reads normal so that rules out the +13V derived on that board thru R965 and C911.

Patience, dear boy, patience. You only have to wait for Bad Things to bite you.

Me, obsessed? Shurely shome mishtake.

[bd139]

Oh fun that board is full of the wankers that were in my 7L12. Start with the brown top ones!

[mnementh]

"Kill them all. God will know his own." ~Abbot Arnaud Amalric ~med the Tant-Slayer

mnem
*egregious* 

[BU508A]

Oh fun that board is full of the wankers that were in my 7L12. Start with the brown top ones!

The ceramic disc capacitors?

[bd139]

Nope the tants disguised as silver mica ones if you look from above 

[med6753]

This is getting real intense. It's looking more and more like I have a short in the board itself.  I've pulled and isolated just about every component hanging on the +15V bus and it's still shorted to ground. As much as I don't want to do it I'm going to cut the land in a choice spot where it branches in two directions and see what happens. 

[mnementh]

Huh...  https://www.sawstop.com/

mnem
*DIYily*

[Mr. Scram]

Huh...  https://www.sawstop.com/

mnem
*DIYily*

Too bad they're apparently dicks, which prevents adoption. I think Bosch has figured out a non destructive variant by now which has been sued out of shops by Sawstop.

[med6753]

This is getting real intense. It's looking more and more like I have a short in the board itself.  I've pulled and isolated just about every component hanging on the +15V bus and it's still shorted to ground. As much as I don't want to do it I'm going to cut the land in a choice spot where it branches in two directions and see what happens. 

I made what I thought was a strategic cut in the land and BOTH sides still reading short to ground. I think I need to step away from this for today and start fresh in the morning. 

[tggzzz]

This is getting real intense. It's looking more and more like I have a short in the board itself.  I've pulled and isolated just about every component hanging on the +15V bus and it's still shorted to ground. As much as I don't want to do it I'm going to cut the land in a choice spot where it branches in two directions and see what happens. 

Inject a current into the +15V and Gnd rails. Measure the voltage drop along the +15V rail. That will give you a clue where the current is ending up.

Repeat, injecting the current into a different location on those rails. That will give you another clue.

[med6753]

That is a good idea and I will add it to tomorrow's "to do" list. 

[bitseeker]

There is no end of this road, is it?      

You can check out any time you like, but you can never leave.

Hotel California, The Eagles, in case you don't get the reference.

Yes, I know this, since I do really like the music from this aera.
And, usually, I'm holding this against to some of my friends.

And now what comes is all your fault, you gave me the idea for a TEA hymn!
And I'm sorry for the crude english, it is not really my mother tounge
but I tried and did the best I could do.
Any improvements, corrections, whatever are very welcome!  

...snip...

That was hilarious. Well done, BU!

[bitseeker]

don't you just hate to break a promise to yourself?

said 4 years  ago when we downsized and moved......"no more tube radios".

walked away from this POS radio and almost made it 50 ft before turning around and offering the guy 20 bucks (this morning at the berryville hamfest).

Wow, that enclosure looks like it weighs a ton and bullet proof to boot. Cool looking radio.

[bitseeker]

Bitch Lives.

Woah! Post-ception in that post and its pic.

[bitseeker]

How hard can it be to modify a 5221 (usually counts using 60Hz line freq as reference) to take any frequency line input. The 5221 has an option to do that - the board is a simple Xtal and 7 series divider.
I build the Xtal and divider before I RTFM, - the mod also needs a new HP only ASIC!  FFS.
So how hard can it be to emulate the 17Vpp AC the unit uses!
So I get a 6MHz Xtal, rebuild the divider, I need some higher volts - the only convenient way was to rectify the 17V - gives 8.5V - not enough to drive the gate (of course!) so I bodge in a ICL7660 voltage doubler.
The unit can handle extra digits, so I thought I would push it as far as I could. By pulling off a 100x faster clock, ie 6kHz, not 60Hz, the unit now counts reliably to 9MHz, needing about 100mVpp min to count. A new switch at the back , switches in the 100x 'feature'. I have left a note inside about how to undo it.
It can now come off the 'repair stack'
I need psychotherapy though!
Rob

You actually pulled it off. Awesome, Rob!

Added to POI.

[bitseeker]

Huh...  https://www.sawstop.com/

Thanks. I've wondered how those things detect fingers so quickly. It's a shame that it uses a self-destructing brake (more profit!). It seems you could make a faster blade retractor instead.

[mnementh]

How hard can it be to modify a 5221 (usually counts using 60Hz line freq as reference) to take any frequency line input. The 5221 has an option to do that - the board is a simple Xtal and 7 series divider.
I build the Xtal and divider before I RTFM, - the mod also needs a new HP only ASIC!  FFS.
So how hard can it be to emulate the 17Vpp AC the unit uses!
So I get a 6MHz Xtal, rebuild the divider, I need some higher volts - the only convenient way was to rectify the 17V - gives 8.5V - not enough to drive the gate (of course!) so I bodge in a ICL7660 voltage doubler.
The unit can handle extra digits, so I thought I would push it as far as I could. By pulling off a 100x faster clock, ie 6kHz, not 60Hz, the unit now counts reliably to 9MHz, needing about 100mVpp min to count. A new switch at the back , switches in the 100x 'feature'. I have left a note inside about how to undo it.
It can now come off the 'repair stack'
I need psychotherapy though!
Rob

Nice work on the mod 

Agreed on both counts!!!    

Thanks for sharing the product of your madness, however! 

mnem
 

[bitseeker]

This Dana 5330 voltmeter listed on ePay.com in the wrong category may be of interest here, it has nixie bulbs:
eBay auction: #254237958335

David

Damn you!!!       

Hmm. Does that mean you own it now? Looking forward to the teardown.

[mnementh]

Bitch Lives.

Woah! Post-ception in that post and its pic.

I knew you'd notice, whether or not anybody else did. *

Right now I'm tearing my 1KW+ ( Yes REALLY!!!) PSU down to see if I can change the fan... this is my 2nd one of these, and the fan in it sounds like a effing jet engine (unlike the one in my first unit) 100% Duty Cycle so I'm thinking to add load-based control integration for its fan as well.

*I was tempted to go another fold or two more... but by that point I was just outright knackered and needed to go lie down before keeled over.

mnem
*recursion-ily*

[tautech]

I knew you'd notice, even if nobody else did. *

Was the thanks given not enough ?

[mnementh]

Yeah, of course it was... THANKS!!! 

There... better now?

mnem
*recursive* 

[mnementh]

Right now I'm tearing my 1KW+ ( Yes REALLY!!!) PSU down to see if I can change the fan... this is my 2nd one of these, and the fan in it sounds like a effing jet engine (unlike the one in my first unit) 100% Duty Cycle so I'm thinking to add load-based control integration for its fan as well.

mnem
*recursion-ily*

Uggghhh... I think it REALLY IS running 100% duty cycle; comparing against the pics from this teardown, it looks like they omitted a thermal-control loop and are running the fan WOT/100% Duty. 

Gonna be off the internet for a while then... need to dismantle 1KW PSU #1 to draw up a BOM so I can retrofit. 

mnem
See you all on the other side...

[VK5RC]

How hard can it be to modify a 5221 (usually counts using 60Hz line freq as reference) to take any frequency line input. The 5221 has an option to do that - the board is a simple Xtal and 7 series divider.
I build the Xtal and divider before I RTFM, - the mod also needs a new HP only ASIC!  FFS.
So how hard can it be to emulate the 17Vpp AC the unit uses!
So I get a 6MHz Xtal, rebuild the divider, I need some higher volts - the only convenient way was to rectify the 17V - gives 8.5V - not enough to drive the gate (of course!) so I bodge in a ICL7660 voltage doubler.
The unit can handle extra digits, so I thought I would push it as far as I could. By pulling off a 100x faster clock, ie 6kHz, not 60Hz, the unit now counts reliably to 9MHz, needing about 100mVpp min to count. A new switch at the back , switches in the 100x 'feature'. I have left a note inside about how to undo it.
It can now come off the 'repair stack'
I need psychotherapy though!
Rob

Nice work on the mod 

Agreed on both counts!!!    

Thanks for sharing the product of your madness, however! 

mnem
 

I resemble that remark!

[Specmaster]

This is getting real intense. It's looking more and more like I have a short in the board itself.  I've pulled and isolated just about every component hanging on the +15V bus and it's still shorted to ground. As much as I don't want to do it I'm going to cut the land in a choice spot where it branches in two directions and see what happens. 

Bring in a 15v (limit the current to say 1A) supply from your bench PSU and if you have either a thermal imaging camera or even a infra-red thermometer look around the board for signs of extra heat. If you don't have either, then you could use something like lighter fuel spread in areas on the board and components, (not too much as to make it a hazard) and then look for areas where the fuel evaporates quickest due to the increased temperature caused by the short circuit and then bingo, you'll have found the source of your problem.