Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

I'm after stuff I can ponce off on ebay that doesn't cost a lot in postage mostly this time. Anything that makes me go "ooh" and "ahh" may come along for the ride.

Shitty weather is going to marvellous. I'm getting kitted out and going to hit the Chiltern hills (Ivinghoe Beacon) after lunch before it gets dark. 10 miles of being pissed on is my idea of a good afternoon

Strange, I never had you down as person who indulged in watersports 

[bd139]

Hahaha not the golden variety 

Edit: I'm not superstitious at all but this is a good omen for Harwell. Latest Soldersmoke podcast came out last week. Will stuff that on in the car on the way. It's motivational and gets you in the right state of mind for buying stuff. I'm more interested in stuff at hamfests if I've listened to this on the way. http://soldersmoke.blogspot.com/2020/02/soldersmoke-podcast-217-beach-trip-30s.html

[tautech]

And I have another question:

What is this "Hidden user" anyway?

Dave anonymously dropping in to check up on us.

[Zucca]

We used to call them "ash boxes" at university.

Good old time, I had the pleasure to be in a "Perito Tecnico in Elettronica" High-School, which is basically a high level eletronic school for teens (really an Italian Masterpiece).
We were studing poles and zero and op-amps at the age of 17. so so cool.

Back in the second year we were in a lab, in the last desk row (it is always there...) one dude sitting was asking to send back the 9V batteries.
The challenge was to connect them is series and then stick the + and - 4mm banana jacks in the mouth.

9x7=63V was enough to win that day. Second place was of course 54V.

I still remember the spastic face with the red and black cable in his mouth.

[Specmaster]

And I have another question:

What is this "Hidden user" anyway?

Dave anonymously dropping in to check up on us.

Can he do that while he's in Dove Canyon then?

[Specmaster]

Hahaha not the golden variety 

Edit: I'm not superstitious at all but this is a good omen for Harwell. Latest Soldersmoke podcast came out last week. Will stuff that on in the car on the way. It's motivational and gets you in the right state of mind for buying stuff. I'm more interested in stuff at hamfests if I've listened to this on the way. http://soldersmoke.blogspot.com/2020/02/soldersmoke-podcast-217-beach-trip-30s.html

The Harwell rally is in Didcot Leisure Centre I think, is that right, its an inside jobby so it won't matter to much what the weather is like really?

[med6753]

And I have another question:

What is this "Hidden user" anyway?

Dave anonymously dropping in to check up on us.

Can he do that while he's in Dove Canyon then?

It would be nice if the boss at least posted once and said "you guys are cool" or "you guys are nuts"  or something...anything. 

[BU508A]

I just checked hamfest calendar for my local area. Nothing until May and even then it may not be worth it. 

Bring donuts to the hamfest. 

[med6753]

I just checked hamfest calendar for my local area. Nothing until May and even then it may not be worth it. 

Bring donuts to the hamfest. 

And feed the Hobos?    I can think of sooooo many other activities I'd rather do. 

[tautech]

And I have another question:

What is this "Hidden user" anyway?

Dave anonymously dropping in to check up on us.

Can he do that while he's in Dove Canyon then?

It would be nice if the boss at least posted once and said "you guys are cool" or "you guys are nuts"  or something...anything. 

We did get a tiny mention on Amphour some weeks back and that might be all for fear of encouraging us any further.
Otherwise I guess he just drops by to suss out ideas for videos and keep an eye on the mayhem.

[med6753]

And I have another question:

What is this "Hidden user" anyway?

Dave anonymously dropping in to check up on us.

Can he do that while he's in Dove Canyon then?

It would be nice if the boss at least posted once and said "you guys are cool" or "you guys are nuts"  or something...anything. 

We did get a tiny mention on Amphour some weeks back and that might be all for fear of encouraging us any further.
Otherwise I guess he just drops by to suss out ideas for videos and keep an eye on the mayhem.

What are we? A force to be reckoned with? 

[grizewald]

The Scopex turned up earlier today. Although it seems to work, the trigger is very dodgy, the channel A vertical position makes the traces wobble around like mad things when I adjust it and the whole thing needs a damn good clean. A graticule would be nice as well, but I guess that can be easily solved with some OHP film and my laser printer. It might also be nice to see the rising and falling edges on that square wave!

[tggzzz]

We used to call them "ash boxes" at university. The 1x and 10x ranges were always populated with ash instead of resistors 

The local hackspace has one; I affixed a label detailing the problem and conditions under which it might become a high resistance box.

Yesterday a benefactor donated a 100kHz-1GHz Philips sig gen. I'll have a look at it in detail sometime, since it might be useful to me.

My sig gens go up to 15GHz, but are evaluation boards. The TI one has low noise sidebands, but the software is an abortion. The software is very good at letting you see what values are poked into what registers, and iffy combinations that you choose - but AFAIK TI refuses to let anybody know the algorithms used to choose the "optimum" values

[tggzzz]

Hahaha not the golden variety 

Edit: I'm not superstitious at all but this is a good omen for Harwell. Latest Soldersmoke podcast came out last week. Will stuff that on in the car on the way. It's motivational and gets you in the right state of mind for buying stuff. I'm more interested in stuff at hamfests if I've listened to this on the way. http://soldersmoke.blogspot.com/2020/02/soldersmoke-podcast-217-beach-trip-30s.html

The Harwell rally is in Didcot Leisure Centre I think, is that right, its an inside jobby so it won't matter to much what the weather is like really?

Correct, but punters can be put off by inclement weather.

It is large: I believe there are 180 tables or so spread over several rooms! The stuff seems better than average, probably because Harwell (Diamond Synchrotron and other stuff) and Oxford are nearby.

Last year I picked up a couple of interesting silent key Tek generators (see posts passim about levelled 100MHz and time-mark generators), much to bd's disgust. I almost picked up an ancient "learn to program an 8080 with switches) teaching aid, but sanity prevailed.

[med6753]

The Scopex turned up earlier today. Although it seems to work, the trigger is very dodgy, the channel A vertical position makes the traces wobble around like mad things when I adjust it and the whole thing needs a damn good clean. A graticule would be nice as well, but I guess that can be easily solved with some OHP film and my laser printer. It might also be nice to see the rising and falling edges on that square wave!

I just noticed. You can only Trigger on Channel A? Really? 

[AVGresponding]

In case anyone needs more DMM digits, here's a decent deal on a well-optioned Fluke 8505A ($106ppd) : eBay auction: #184013841856

No relation to the seller, just hoping someone will remove the temptation.

Dammit, stop trying to empty my wallet! I might be saved only by the seller not wanting to ship to the UK, or at a sensible price anyway.
EDIT: My funds are safe, the seller doesn't ship internationally. I am simultaneously happy and sad...

I still have an Xbox 360 and 30-40 games last used 7 or 8 years ago .... There is also a PS2 in the same box with another bunch of games. Something that is unlikely to ever become retro cool and gain value 

"Phat" PS2s are already retro cool, especially in colours other than the common black. Even slim ones are going up a bit, in non-black.

What are we? A force farce to be reckoned with? 

Fixed that for you...   

[bd139]

We used to call them "ash boxes" at university. The 1x and 10x ranges were always populated with ash instead of resistors 

The local hackspace has one; I affixed a label detailing the problem and conditions under which it might become a high resistance box.

Yesterday a benefactor donated a 100kHz-1GHz Philips sig gen. I'll have a look at it in detail sometime, since it might be useful to me.

My sig gens go up to 15GHz, but are evaluation boards. The TI one has low noise sidebands, but the software is an abortion. The software is very good at letting you see what values are poked into what registers, and iffy combinations that you choose - but AFAIK TI refuses to let anybody know the algorithms used to choose the "optimum" values

If it's a PM5390, they are quite nice. Have sweep and stuff. I'm still after a decent sweep RF signal generator. Bottom end China hasn't mustered anything with decent attenuators yet 

Hahaha not the golden variety 

Edit: I'm not superstitious at all but this is a good omen for Harwell. Latest Soldersmoke podcast came out last week. Will stuff that on in the car on the way. It's motivational and gets you in the right state of mind for buying stuff. I'm more interested in stuff at hamfests if I've listened to this on the way. http://soldersmoke.blogspot.com/2020/02/soldersmoke-podcast-217-beach-trip-30s.html

The Harwell rally is in Didcot Leisure Centre I think, is that right, its an inside jobby so it won't matter to much what the weather is like really?

Correct, but punters can be put off by inclement weather.

It is large: I believe there are 180 tables or so spread over several rooms! The stuff seems better than average, probably because Harwell (Diamond Synchrotron and other stuff) and Oxford are nearby.

Last year I picked up a couple of interesting silent key Tek generators (see posts passim about levelled 100MHz and time-mark generators), much to bd's disgust. I almost picked up an ancient "learn to program an 8080 with switches) teaching aid, but sanity prevailed.

It is a big put off I reckon. Last year it was freezing in the queue and not a lot of people were particularly prepared for that. I heard some complaining that this was the last year they were going. I wasn't particularly prepared as well. Also I was late because I wasn't paying particularly good attention to the route thanks to Soldersmoke podcast and ended up doing a 15 min jaunt too far up the wrong sodding road and had to stop half way and hobble off into some woodland to set the morning coffee free

I'm not terribly disappointed I didn't get those Tek goodies. I worry more that they end up in bad hands and will be destroyed. Fortunately you got them so they were ok

[grizewald]

The Scopex turned up earlier today. Although it seems to work, the trigger is very dodgy, the channel A vertical position makes the traces wobble around like mad things when I adjust it and the whole thing needs a damn good clean. A graticule would be nice as well, but I guess that can be easily solved with some OHP film and my laser printer. It might also be nice to see the rising and falling edges on that square wave!

I just noticed. You can only Trigger on Channel A? Really? 

Yeah, another of its little idiosyncrasies.

[grizewald]

Time for some "covers off" pictures of the Scopex.

Top side.



Not so much to see. Here's the front end attenuators.



Time base selector.



Turning it over reveals that the chips have '79 - '80 date codes.



And here are the front ends, with way too many trimmer caps.



Lastly, what's with these trimmers? How can something made out of plastic turn grey and furry?

[ArthurDent]

Nice old 0.1% decade resistor box in the USA for not a lot ($32 USD plus post) if anyone is interested freight to me is OTT eBay auction: #323827828448

I picked up a really nice one on eBay for next to nothing some time ago.

[bd139]

@grizewald: thanks for the photos. Looks quite pleasant to work on. Are those trimmers Piher ones? I've seen furry Piher ones before. Not sure what does it. Tek headers do it as well.

[Specmaster]

@grizewald: thanks for the photos. Looks quite pleasant to work on. Are those trimmers Piher ones? I've seen furry Piher ones before. Not sure what does it. Tek headers do it as well.

Certainly look like they are, the rest of the board looks spotless, can't help but think man it sure looks empty in there.

[xrunner]

1,965 pages of posts ...

 

[grizewald]

@grizewald: thanks for the photos. Looks quite pleasant to work on. Are those trimmers Piher ones? I've seen furry Piher ones before. Not sure what does it. Tek headers do it as well.

Pleasure! It's certainly not cramped in there, that's for sure. The service manual includes a component map to make up for the lack of silk screen, so it shouldn't be too hard to fix things.

I'm not quite sure of the brand for the trimmers. Some still have the original black colour, and some have gone grey and furry. Never seen that before. I wonder what chemical process is at work there?

It also seems that any time faster than 50μs/div stops the trace, so it looks like there's either a dead cap or a bad connection somewhere. Otherwise, it seems quite stable, apart from the A channel vertical position.

First task is printing a graticule holder to fit on the metal pegs around the screen and then get a 10 x 8 graticule printed.

It does a nice job of displaying an AM signal, and it confuses the sensor on my phone's camera very nicely! I can assure you that the trace is nicely green in reality with just an intensity difference at the zero modulation points.

[WastelandTek]

The Scopex turned up earlier today. Although it seems to work, the trigger is very dodgy, the channel A vertical position makes the traces wobble around like mad things when I adjust it and the whole thing needs a damn good clean. A graticule would be nice as well, but I guess that can be easily solved with some OHP film and my laser printer. It might also be nice to see the rising and falling edges on that square wave!

Nice clean looking trace!

That rivals my old Hitachi.