Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

You're nuts, aren't you?

You are what you eat:   

mnem
 

[Cerebus]

If it's like most companies I've worked for their IPAM will be based on snooting coke in the toilets and counting the dots of blood on the tissue to issue new network numbers.

At my last gig it was determined by a very grumpy Irish lass throwing darts at the door and then measuring how far out of the other side she'd managed to get the points to come. Anybody who has worked at/for that particular enterprise on their network will immediately recognise what corporation it was.

This is the same place that the default root password for Linux machines was "<companyname>%768". (OK, it wasn't exactly that, but it was just as stupid and 'cunningly' constructed to meet Security's password complexity requirements while simultaneously missing them by about the distance between Earth and Jupiter).

[mnementh]

... the only real cure is cleaning the carbon pads with alcohol to expose fresh carbon matrix every few years or replacing the silicone membrane itself with a brand-new one.

Not true. As of this morning I have repaired the pads, and in a way that no one has mentioned here, nor did I see the way I did it on any internet search (not to say it doesn't exist out there). The alcohol cleaning did nothing at all because they were already cleaned before as I told you. Nothing else came off the the pad and I scrubbed them very well. Under the microscope they remained as they were before I cleaned them. As well, they did not perform any better when tested after this new alcohol cleaning.

What I have done this morning has fixed them and they should remain so for a long time. They work as new now with barely a touch of the key. I hope this will help others as well.

I will do a write-up and get pics assembled, until then enjoy the drama.

 

No drama here. I'd love to see a simple permanent fix to this problem which has plagued electronics for decades. I just hope no abrasives were involved... that tactic does destroy SOME carbon pads with very little warning and no remorse.

mnem
 

[Cerebus]

I never bought one of those, it's like to admit I am dummy.

I always thought that, if you are a dummy, then you wouldn't be smart enough to realize that you need to buy one of those books. 

Those are read by people how are intelligent enough to know that they are an ignoramus when it comes to some particular subject and humble enough to admit it.

[Specmaster]

I never bought one of those, it's like to admit I am dummy.

oops...

Unless you really want the very latest edition, you can get loads of these and other technical books as PDF downloads free here https://www.pdfdrive.com/

[med6753]

https://www.eevblog.com/forum/repair/repairrestoration-of-a-tek-type-561b/

Been a fun project so far but every time I fix one thing something else crops up.

I'm going to let it bake for a few hours to see if anything else rears it's ugly head.

 

Are you suitably prepped?



 

"You're a riot, Alice" 

[Cerebus]

Pffft... amateur. I am a ASE CERTIFIED Munter.    And that's just the ones small enough to fit in a drawer. 

Oh aye laddie? Ye dee ken what a munter is, divnae ye?

[xrunner]

No drama here. I'd love to see a simple permanent fix to this problem which has plagued electronics for decades. I just hope no abrasives were involved... that tactic does destroy SOME carbon pads with very little warning and no remorse.

No animals or oscilloscopes were harmed in the recording of this event. 

[Neomys Sapiens]

After 2 months i'm still waiting for my USB connectors. Look like I will have to change my plan for my Jim Williams pulse generator.

Ha got my connectors in the mail today. Took 103 days to get here from China. Used to take 30 days at most.

Look like 100 days is the new norm for me. Got another one after 102 days.  Was initially ordered in February 

My cheap 'genuine' LM3909s from China, which I ordered on the 10.5., were in the Post yesterday.
They look normal, not tested yet.

[mnementh]

Pffft... amateur. I am a ASE CERTIFIED Munter.    And that's just the ones small enough to fit in a drawer. 

Oh aye laddie? Ye dee ken what a munter is, divnae ye?

Aye... and so should ye, as 'twere ye what gevv' me me th' name, indirectly at least, so long ago...

https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg1874546/#msg1874546

https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg1875053/#msg1875053

https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg1875128/#msg1875128

mnem
And yes, I grok the "beaten with a ugly stick" variant as well; which, honestly, I cannae dispute. 

[Neomys Sapiens]

Klystron on its way. Run for the hills, the sky is falling 

Noted. Looking for a bigger Klystron.

[Neomys Sapiens]

The Tek alignment tools have arrived too. Along with a selection of adaptors extending further my capabilities in the SMC and SSMA sectors. The kit has Tek No. 003-0500-00. They are in very fine condition. The accompanying Tek sheet is marked with a check for completeness by a GAF supply sargeant.

[AVGresponding]

This is absolutely normal; a byproduct of oxidation which happens upon exposure to air with ANY baryonic matter to some extent. Carbon is a stable element, but the binders used to keep it on the silicone membrane keypad degrade with age and the surface becomes "glazed".

Add a little electrolysis from the charged PCB contacts and you get this condition which the only real cure is cleaning the carbon pads with alcohol to expose fresh carbon matrix every few years or replacing the silicone membrane itself with a brand-new one. And since they haven't been made in decades, that's pretty hard to make happen; hence the carbon pad repair kits. 

mnem
 

Good luck getting helium to oxidise   :3

[Mr. Scram]

I never bought one of those, it's like to admit I am dummy.

Almost everyone is a dummy at most things, except those few experts at everything we've got here. 

[Mr. Scram]

Another useful tip, is that you can get some silver paint on the carbon pads if they are failing.

Traditional black carbon ink is something I've seen being used too.

[Cubdriver]

I never bought one of those, it's like to admit I am dummy.

Almost everyone is a dummy at most things, except those few experts at everything we've got here. 

Expert - someone who knows more and more about less and less, until ultimately they know everything about nothing.

-Pat

[xrunner]

Expert - someone who knows more and more about less and less, until ultimately they know everything about nothing.

-Pat

I thought I was wrong once, but after reviewing it, I was mistaken in saying that. 

[mnementh]

This is absolutely normal; a byproduct of oxidation which happens upon exposure to air with ANY baryonic matter to some extent. Carbon is a stable element, but the binders used to keep it on the silicone membrane keypad degrade with age and the surface becomes "glazed".

Add a little electrolysis from the charged PCB contacts and you get this condition which the only real cure is cleaning the carbon pads with alcohol to expose fresh carbon matrix every few years or replacing the silicone membrane itself with a brand-new one. And since they haven't been made in decades, that's pretty hard to make happen; hence the carbon pad repair kits. 

mnem
 

Good luck getting helium to oxidise   :3

Ha-ha... and the list of similar bell-end cases goes on & on. Given the right conditions and enough time etc...

mnem
"The difficult we accomplish as scheduled. Impossible may take slightly longer."

[mnementh]

An interesting "Noob's Guide" for anybody who has seriously considered one of those cheap CNC Mills for quick one-off PCB fab.

mnem
 

[URI]

An interesting "Noob's Guide" for anybody who has seriously considered one of those cheap CNC Mills for quick one-off PCB fab.

mnem
 

Veerry tempting!
But not enough room here saves me from my wifes disaproval.      

[Neomys Sapiens]

For the headset, I got a LogiLink HS0002 as first measure, which will fit the T60 directly. Although I ordered both the Y-cable proposed by AVG responding as well as the reverse version (to connect a two-plug headset to a integrated jack).
I do not yet know what will really suit me, because for earphones alone I am used to ultralight things which procect slightly into the ear without plugging it with a very light folding frame. Finding somthing like this with a mic would be lovely. Maybe I will try a PLANTRONICS HW540 EncorePro. Anything that is closed and/or puts pressure on my head and ears is a no-go.

[Saskia]

been fooling around with some X99 chipsets. Found my microSD adapters along with some rare metals (~ 2 grand) in my mailbox. Normally I would expect having to sign off on such a parcel ...

As for the klystron: hey, it's rated at 250 mW, not 150 MW. What's yer problem ? I don't think this is more dangerous than 10 kgs of liquified N2O in that steel can boiling in the sun ...

[med6753]

So the CRT in the Type 561B may not be going bad after all. I went to measure the HV and it's only about -1.6KV. It should be -3.3KV. That's odd. So I started checking the HV Oscillator first and clumsy me accidentally shorted the input to the oscillator from the PSU. Result is the 125ma HV fuse popped. No other damage. But do you think I have a 125ma fuse on hand? Hell no. Order submitted and I'll have some Friday.

And no, I'm not jumpering the fuse to continue troubleshooting. I may be dumb but I ain't stupid. 

[Saskia]

I could give you some in 7.62x51 with acoustic overload indicator 

[duckduck]

My DHL delivery has been at stop 209 of 216 for the last 2 hours 

Stop 209: