Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

Yeah, med already mentioned that; clearly the plugin was handled carelessly and got dropped. Happens a lot more than we'd care to admit; an occupational hazard with these scopes.

med, dooya think that mismatched part coulda just been a old blind bastard like me misread the numbers...? I mean, it was just one digit, and we all know those plastic packages have a lot of variation. Alternately, coulda-shoulda been a matched pair, which obvi they are not, even if it was the same part number.

mnem
 

Yea, that's the Channel 1 Trigger Only switch and it works OK despite being slightly bent so I'm leaving it.

OK, just one digit off. Yea, shit happens. But wouldn't the fact that the damn thing didn't work after the change be a fucking clue? 

Yeah, sure... but we have no idea how much time said poor bastard worked on it already; s/he may have just decided to put it up for sale rather than Widlarize it good & proper to save his/her sanity. 

And if they HAD been a little more patient/sharper on the repair skillz, you wouldn't have gotten the deal you got. 

mnem
 

[mnementh]

Well I don't know. All these people getting exciting post and all that I got today was a bastard file.

Oh, and a box for the cat - but that's most deliveries.

I got nice, boring printer ink (so we can print out a new lease if we ever actually get one) and rollers so I can do some maintenance on my 3DP if I ever have time again. 

mnem
yey, Amazon... woot...?

[med6753]

Yeah, med already mentioned that; clearly the plugin was handled carelessly and got dropped. Happens a lot more than we'd care to admit; an occupational hazard with these scopes.

med, dooya think that mismatched part coulda just been a old blind bastard like me misread the numbers...? I mean, it was just one digit, and we all know those plastic packages have a lot of variation. Alternately, coulda-shoulda been a matched pair, which obvi they are not, even if it was the same part number.

mnem
 

Yea, that's the Channel 1 Trigger Only switch and it works OK despite being slightly bent so I'm leaving it.

OK, just one digit off. Yea, shit happens. But wouldn't the fact that the damn thing didn't work after the change be a fucking clue? 

Yeah, sure... but we have no idea how much time said poor bastard worked on it already; s/he may have just decided to put it up for sale rather than Widlarize it good & proper to save his/her sanity. 

And if they HAD been a little more patient/sharper on the repair skillz, you wouldn't have gotten the deal you got. 

mnem
 

It wasn't a screaming deal but a fair deal. Was owned by US Navy. And I'll bet it was some drunken swabbie who installed the wrong transistor and then the gov decided to surplus it.   

[Saskia]

https://youtu.be/qGyPuey-1Jw

[mansaxel]

I'm probably better off not watching. The images you can find on the electronics sites these days...

Here you go:
mnem
 

Yeah, I did figure out a way. We do   murals like that in Sweden.

https://en.wikipedia.org/wiki/Carolina_Falkholt

[tonyalbus]

This Fluke 1920A Frequency Counter is amazing!!.  9 Digits, op to 1400 Mhz..    from 1977 ..how is that possible in that time.

[factory]

I'm currently working on repairing the power supply board out of my late 60's HP 180A oscilloscope, it's been sitting in the repair queue for quite a while, since the normal fault finding procedure involves wasting lots of (now expensive) fuses.

To test it outside the scope requires at least three power supplies, the HP 711A & Farnell E350 supplied the normally unregulated inputs to the +100V & -100V rails, a third low voltage supply was used for the extra +105V rail used internally on this board and some 2N3055 pass transistors were also needed as these are external to the board.



The +100V output was working fine, but the -100V output was high & couldn't be adjusted, this was traced to Q416 after the voltage divider used for the adjustment, it had no effect as it was found to be partly open circuit.
Note: Q416 is one of those 1854-0071 (4-071) transistors that were supplied from various different sources and hence the pinout can be different, a salvaged replacement restored normal operation.


Hopefully I can get some time in a few days to work on the remaining supplies on the board, which all use the -100V as a reference.

David

[med6753]

Unfortunately it's usually a bad thing when the reference supply goes bonkers and high because it could possibly damage the other outputs that use it as it's reference. Hopefully the remaining carnage will be minimal.

[Robert763]

 I've started tearing down thet 40W laser. Looks like the seller robbed a mirror from it but I'm not bothered.
It is clearly a repurposed LaserScope 800 medical laser. Lots of power supplies but whoever built it was not an electronics engineer. They kept this Huge 18" x 12" PCB just to drive a heater on the KTP frequency doubler crystal

And the matching Zenith ZPS300 2 output power supply. They also stuck in a couple of 12 V Meanwells - literally - they epoxied them to the optical base plate. They didint do a very good job, a bit of pressure in the right place and they popped off. Epoxy has poor peel strength and they didn't prepare the surfaces.

Found the manual for the original LaserScope and the arc lamp supply looks like Med's dream electrolytic Widlarizer - 4 kW, 0-35 A constant current with 250 V compliance. If that's not enough to get things started it applies a 800 V "boost" and 25 kV trigger pulses to get the current flowing
Photos when I get it out of the case.

[med6753]

Found the manual for the original LaserScope and the arc lamp supply looks like Med's dream electrolytic Widlarizer - 4 kW, 0-35 A constant current with 250 V compliance. If that's not enough to get things started it applies a 800 V "boost" and 25 kV trigger pulses to get the current flowing
Photos when I get it out of the case.

NOPE    NOPE    NOPE 

Be careful 

[mnementh]

What could possibly go wrong...? 

mnem
*toddles off to ded*

[Robert763]

I'm sure it's perfectly safe - NOT This is just a caution from the manual:

"CAUTION the output is floating at AC line voltage whenever the AC input is connected, regardless of whether the power supply is enabled."

So the PSU output will kill you even when it's "off". I've had lots of high voltage experence including homemade Ar-ion laser PSUs  but I won't be plugging this in
Apparently the original medical laser had a 5 kW isolation transfomer in the base........

[Zucca]

@Zucca why don't you try this very tasty and yummy apple ? 

Could you imagine to be married with a TEA girl like her?

Two benches one for her and one for me?
Bins of components everywhere?

Don't know... surely I would like to try her out for one week or so... 

PS:Jokes aside, kicking ass stuff. Keep pumping high quality vibrations in the air!

[Saskia]

I'm sure it's perfectly safe - NOT This is just a caution from the manual:

"CAUTION the output is floating at AC line voltage whenever the AC input is connected, regardless of whether the power supply is enabled."

So the PSU output will kill you even when it's "off". I've had lots of high voltage experence including homemade Ar-ion laser PSUs  but I won't be plugging this in
Apparently the original medical laser had a 5 kW isolation transfomer in the base........

you only die once, or so they say ... (adapted from you only live twice) ...

[tggzzz]

I always wanted to listen to the 1812 Overture at concert level ...

This recording is superb. The pitch of the helical track is much larger than usual, so the dynamic range is unbelievable. Of course that means the short piece is spread over both sides of the LP.

Strauss: Also Sprach Zarathustra. Herbert von Karajan. Vienna PO. Decca SDD 175. The Ace of Diamonds label was their top-flight label with the best vinyl, so there is no background hiss.

Shame I'll never be able to appreciate it again.

[Robert763]

And of course the rebuilder used all sensible precautions and connected the high voltage with -
4mm2 EARTH CABLE


I have a whole new respect for the HV insulation of Commando connectors.

[tonyalbus]

And of course the rebuilder used all sensible precautions and connected the high voltage with -
4mm2 EARTH CABLE
(Attachment Link)

I have a whole new respect for the HV insulation of Commando connectors.

[bd139]

May be offline for a few days  . Total shit show . Work crazy busy because our outsourcers are basically off line thanks to political instability. Also eldest got her GCSE teacher graded exam results today which were excellent but we don't know if the government are going to fuck up or do a U-turn etc or not yet because they're a sack of cunts who should be shot

Specmaster: will get back to you regarding those F25 organs when I get a few minutes 

[tonyalbus]

May be offline for a few days  . Total shit show . Work crazy busy because our outsourcers are basically off line thanks to political instability. Also eldest got her GCSE teacher graded exam results today which were excellent but we don't know if the government are going to fuck up or do a U-turn etc or not yet because they're a sack of cunts who should be shot

Specmaster: will get back to you regarding those F25 organs when I get a few minutes 

Good luck!

[BU508A]

And of course the rebuilder used all sensible precautions and connected the high voltage with -
4mm2 EARTH CABLE
(Attachment Link)

I have a whole new respect for the HV insulation of Commando connectors.

  

[BU508A]

May be offline for a few days  . Total shit show . Work crazy busy because our outsourcers are basically off line thanks to political instability. Also eldest got her GCSE teacher graded exam results today which were excellent but we don't know if the government are going to fuck up or do a U-turn etc or not yet because they're a sack of cunts who should be shot

Specmaster: will get back to you regarding those F25 organs when I get a few minutes 

Congrats to your eldest and all the best from me.
And for you: take care and with all this stress have some time a cup of tea or something. Look after yourself.

[med6753]

May be offline for a few days  . Total shit show . Work crazy busy because our outsourcers are basically off line thanks to political instability. Also eldest got her GCSE teacher graded exam results today which were excellent but we don't know if the government are going to fuck up or do a U-turn etc or not yet because they're a sack of cunts who should be shot

Specmaster: will get back to you regarding those F25 organs when I get a few minutes 

Have a blast. Where are your outsourcers located?

[bd139]

Belarus 

[Ice-Tea]

 

[tggzzz]

And of course the rebuilder used all sensible precautions and connected the high voltage with -
4mm2 EARTH CABLE

Just hope you don't buy a house where such a person has done DIY improvements. "Structural wall? What's that?" etc