Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

Talking of buying stuff, I’m convinced eBay has wrecked itself here in the U.K.  They have been doing lots of offer weekends where selling fees are max £1. There is literally nothing interesting at all listed when those aren’t on now. Not a damn thing.

Your not wrong, maybe Ebay ought to consider reducing their normal fees to maybe a maximum £2 on everything. After all it must still be hugely profitable for them given the huge volumes of items sold on it every day and also lower fees would encourage more people to sell on their platform and so thus increase their revenue at the same.

[Cerebus]

Yeah, this is one thing that concerns me with moving to Toronto... one thing I've heard over and over again is that in social situations, Canadians are "polite to a fault".

How the fuck am I going to teach my kids to be polite so they're not ostracized when I'm just 6 kinds of rude, crude, ignorant & socially unacceptable?   

mnem
Okay, 7 kinds... fuck me. 

Speaking as Brit with a fair bit of experience of Canadians both here and in their native land, or "Canada, eh" as they call it, I haven't found them to be notably more polite than I'd expect the average Brit to be; so you should be OK adjusting to their quaint ways.

What they are is much less likely to be aggressive if something goes wrong. So a couple of average Joe working class Canadians who have a fender-bender are more likely to first ask if everyone's OK, whereas a Brit will probably enquire exactly what kind of idiot the other driver is (often with suggestions as to the precise kind of idiot the inquisitor envisages they may be) and of course many of our American cousins from the more, ahem, colourful states^* or places that start New seem to think that fists and splenic rage are the appropriate social niceties in these situations. I think it's the slowness to take offence or fly into a rage that garners the Canadians a reputation for politeness from their southern neighbours.

One thing that has surprised me is that I've found the average Canadian to be a bit more racist than the average Brit, as I say a surprise for a people famed for their politeness and generally respectful attitude towards other people. I've heard racial remarks from Canadian friends and relatives that have prompted me to tell people "that's a bit off colour" which I last recall having to say to a fellow Brit no more recently than about 15 years ago and that was an isolated incident with a stranger that I was chatting to in a bar near the Tower of London.

^*I obviously exclude the peoples of the Northern Midwest such as Minnesota, who by this time of year are wearing enough warm clothing that they couldn't hear each other, and even if they could wouldn't be able to get close enough or move fast enough to have a fight.

[mnementh]

All the recent HP 3478A talk made me buy another one. Supposedly, it doesn't power on. It'll be interesting to see if it's a quick fix or a total waste of time. But for only $40 including shipping, how could I resist?

In case you didn't know... User & Service manuals on KeySight.

mnem
"Very helpful... very helpful indeed." Chibila thought to himself.

[Cerebus]

All the recent HP 3478A talk made me buy another one. Supposedly, it doesn't power on. It'll be interesting to see if it's a quick fix or a total waste of time. But for only $40 including shipping, how could I resist?

In case you didn't know... User & Service manuals on KeySight.

If the ones on the Keysight site have been deprived of their schematics (as is their recent habit) I have copies of the ones with schematics.

[bitseeker]

Thanks, guys. No worries. I'm fully armed with manuals and schematics. So, I'm ready to change the fuse when it gets here.

[bitseeker]

Buttons, feet, front panel, LCD, voltage ref. I'm sure there's plenty of good stuff to part out, if it comes to that.

It'll probably power on and work fine. Whoever sold it probably didn't have the outlet strip it was plugged into switched on.

TEA people benefit greatly from those types. 

Exactly. I usually check what else they sell (or have sold), which is usually a good tip-off as to their level of technical expertise.

Oh, I also got some Keithley 705 scanners. Unfortunately, they didn't include any scanner cards. However, the 705 (like the larger 706) has a built-in real-time clock. So, if nothing else, it'll be my lab bench clock that blends in with my other Keithley gear from the "brown" era.

[Mr. Scram]

One of my transformer style wall warts was outputting 16V where 12V was expected, so I swapped it out with another 12V  one. That one puts out 18V.  I guess I killed the regulators in both.

[med6753]

One of my transformer style wall warts was outputting 16V where 12V was expected, so I swapped it out with another 12V  one. That one puts out 18V.  I guess I killed the regulators in both.

Was that under load? Some (most?) of them are unregulated and with no load their output will go high.

[bitseeker]

Yep. Try it under load or pop one open to see if it actually has regulation capability.

[Brumby]

.... or pop one open to see if it actually has regulation capability.

Anyone care to run some odds on that?  I'm putting it into the category of "long shot".  Don't think I've ever noticed a transformer based wall-wart with regulation.

[neo]

Trying to make a sturdier shelf to replace the plastic one i accidentally knocked a beam off and onto my head, at least a pint of blood lost and 8 staples later i'm fine. Why does it freak everyone out when i'm bleeding like a stuck pig and don't seem to become alarmed? Never figured that one out, regardless i can now literally say that I've bled for this. 

[med6753]

Trying to make a sturdier shelf to replace the plastic one i accidentally knocked a beam off and onto my head, at least a pint of blood lost and 8 staples later i'm fine. Why does it freak everyone out when i'm bleeding like a stuck pig and don't seem to become alarmed? Never figured that one out, regardless i can now literally say that I've bled for this. 

Holy crap.....glad you are OK.  TEA shouldn't hurt. 

[neo]

Holy crap.....glad you are OK.  TEA shouldn't hurt. 

TEA hurts plenty when your a dumbass, and the thing is it didn't hurt, a whammy when it hit, then a small itch then they put the damn staples in and all i can say is.. OUCH!

[bitseeker]

Trying to make a sturdier shelf to replace the plastic one i accidentally knocked a beam off and onto my head, at least a pint of blood lost and 8 staples later i'm fine. Why does it freak everyone out when i'm bleeding like a stuck pig and don't seem to become alarmed? Never figured that one out, regardless i can now literally say that I've bled for this. 

Holy crap.....glad you are OK.  TEA shouldn't hurt. 

At least not hurt anything but the pocketbook.

Glad you're OK, neo.

[bitseeker]

.... or pop one open to see if it actually has regulation capability.

Anyone care to run some odds on that?  I'm putting it into the category of "long shot".  Don't think I've ever noticed a transformer based wall-wart with regulation.

Me either.

[Cubdriver]

Trying to make a sturdier shelf to replace the plastic one i accidentally knocked a beam off and onto my head, at least a pint of blood lost and 8 staples later i'm fine. Why does it freak everyone out when i'm bleeding like a stuck pig and don't seem to become alarmed? Never figured that one out, regardless i can now literally say that I've bled for this. 

Holy crap.....glad you are OK.  TEA shouldn't hurt. 

My credit card would beg to differ strongly with that statement...

-Pat

[Housedad]

"Always better to have a hard head than be a hard ass"  Is what my father told me for 40 years every time I hit or broke my skull on something.   he had a fun time with it too, considering that I had about 12 concussions and 3 skull fractures.

Ya bleed like hell from a small head cut,  but no worries,  It just lets the Demons out.

[bitseeker]

Ya bleed like hell from a small head cut,  but no worries,  It just lets the Demons out.

But the TEA remains.

[Specmaster]

Trying to make a sturdier shelf to replace the plastic one i accidentally knocked a beam off and onto my head, at least a pint of blood lost and 8 staples later i'm fine. Why does it freak everyone out when i'm bleeding like a stuck pig and don't seem to become alarmed? Never figured that one out, regardless i can now literally say that I've bled for this. 

So glad that your OK, all that remains now to do is cry, then you can  honestly say that you put your blood, sweat and tears into it[emoji23]

[bd139]

Neo you were lucky there. A colleague of mine a number of years ago had a not too terrible looking dink on the head when some poorly installed rack rails gave out dumping a 4U box right in his temple. No blood or anything. Some minor swearing and got on with the job. About five minutes late he had a fit and ended up in ICU for 3 days with brain swelling and only has partial sight in his left eye now. Head injuries are nothing short of scary.

[Brumby]

So glad that your OK, all that remains now to do is cry, then you can  honestly say that you put your blood, sweat and tears into it[emoji23]

Sounds like he would be more likely to laugh himself to tears.  That still qualifies!

[med6753]

Well this is spooky. This morning when I got home from work I turned on the Tek OS-245 and let it warm up while I got something to eat. As usual the retrace was visible. After eating I look and the retrace is gone! The scope is operating normally. Wonderful, we gots an intermittent.

I did some research on how the retrace blanking is supposed to work and essentially during the blanking phase the Z-Axis Amp is supposed to send a negative pulse to the control grid of CRT resulting in cut off. So I figure now that it's working properly I'll scope that pulse to see what it looks like when working. Problem is I have no idea where that area is on the Z-Axis Amp. Those pages are missing in the manual I have. And if I compare this Z-Axis Amp with a 7603 Z-Axis Amp they look nothing alike. It's like they are totally different scopes. So I'm fishing blind. And I need to be careful because there are somewhat high voltages lurking around there just waiting to bite you.

I did go around with a plastic poke stick and no change. And I can't blame tants because there aren't any. So I'm gonna do more searching and see if I can find a manual that has all the pages. Rats! 

[bd139]

That's interesting. Does it come back or get worse at high sweep speeds?

The blanking implementation on the 475 at least didn't work on one of mine in a similar fashion:



If you look at the blanking pulse (light blue) it had a pretty shit RC time constant on it compared to the input trace above which meant that it didn't start tracing until it was too late and then only blanked half way through the retrace 

This turned out to be a dodgy solder job on one of the coax cables to the board.

[med6753]

That's interesting. Does it come back or get worse at high sweep speeds?

Nope, no change even at high sweep speeds. It's currently rock solid. I even gave it X10 sweep boost and it's fine. 

[GreyWoolfe]

Trying to make a sturdier shelf to replace the plastic one i accidentally knocked a beam off and onto my head, at least a pint of blood lost and 8 staples later i'm fine. Why does it freak everyone out when i'm bleeding like a stuck pig and don't seem to become alarmed? Never figured that one out, regardless i can now literally say that I've bled for this. 

You're not alone.  I get the same thing.  Thankfully, I haven't needed stitches since the early 2000's.  At least, Mrs GreyWoolfe no longer asks where the bruises on my person come from, the standard answer is-I don't know.  She now just points them out to me with a raised eyebrow to make sure I know about them.