Test Equipment Anonymous (TEA) group therapy thread

[Berni]

From the diagram it appears to be coupling the reflected power to the 1st LO back out of that port. But then its also coupling the same thing into the resistor and capacitor mess that seams to be some sort of RF detector and perhaps a mixer of some sort.

Im not exactly an RF expert, but maybe i would make some sense out of if by looking at the entire block diagram in a service manual or something. The thing is quite impressively compact tho for being a spectrum analyzer of such impressive specs back in the day.

[Cerebus]

My assumption would be the 'open' is in the sense of open/load/short calibration and that this is connecting to the circuit that manages an [automatic] 'open' calibration. I have to stress assumption as I've not looked at this bit of kit.

[bd139]

That's just termination for something else in the signal chain. I haven't analysed to signal chain properly yet. The engineering in it seems to be a bit "hey that'll fit in there let's just throw it in".

Well another hour of arguing and reassembling. These things are never quite as bad once you've got used to them. Which is just as well because I forgot the bit of plastic that stops the sweep linearizer from shorting out when I put it back together.

A picture says a thousand words:



(and I must have said fuck about a thousand times inside that).

So that's a working 7603 with three plugins including a 7L12 for a grand total of £130 and slight depletion of my capactor box 

Disclaimer: it probably doesn't work properly but at least looks like it probably works

[xrunner]

So that's a working 7603 with three plugins including a 7L12 for a grand total of £130 and slight depletion of my capactor box 

Great work on that! 

Disclaimer: it probably doesn't work properly but at least looks like it probably works

Is it possible being pessimistic you presumed it wasn't properly working when patient playing would paint pleasure and a party? 

[med6753]

That's just termination for something else in the signal chain. I haven't analysed to signal chain properly yet. The engineering in it seems to be a bit "hey that'll fit in there let's just throw it in".

Well another hour of arguing and reassembling. These things are never quite as bad once you've got used to them. Which is just as well because I forgot the bit of plastic that stops the sweep linearizer from shorting out when I put it back together.


(and I must have said fuck about a thousand times inside that).

So that's a working 7603 with three plugins including a 7L12 for a grand total of £130 and slight depletion of my capactor box 

Disclaimer: it probably doesn't work properly but at least looks like it probably works

You lucky dog! Looks like it's working fine to me. 


....set the controls for the heart of the sun.....the heart of the sun.....the heart of the sun......the heart of the sun....

[Specmaster]

Well done, I had every confidence in you resolving the problem, it looks beautiful and it's value has just skyrocketed, well worth the few thousands fucks you reckon you said while working on it, you took a gamble and hit the jackpot. 

[bd139]

Ok final update on this one. Image heavy.

Remaining parts after the repair: one washer. Have no idea where it came from. One test point I had to desolder to get something and forgot to solder back on. Not bad. I have bagged them up for next time I go inside it when it inevitably snuffs it again.

Tin whiskers in the reference oscillator. These were cleaned out carefully with a brush and a mini vac.



Knackered:



Went straight past this little fellow and assumed he was a silver mica cap. Nope, camoflage brown top!



Properly reassembled:



Now I've RTFM and know there is a zero marker it actually makes sense. 10MHz at 0dBm out of my DG1022Z:



Body count.



And on that note I'm going to bed 

[Specmaster]

Thats a job well done and now you are the proud owner of a working SA, and a scope all in one lovely convertible frame for peanuts, bravo 

[Wolfgang]

Chapeau !

Well done. Another piece of vintage equipment saved from the scrapyard. Repairing old junk is a bit of solving a murder mystery. You cannot sleep before the culprit(s) are found and executed and everything is under perfect control again.

[bd139]

Went to bed with a copy of the 7L12 manual in hand. Good break from Gravity's Rainbow.

Well screw me perhaps I should have read the entire manual first. Turns out you don't need to take it to bits to get at the gubbins. Undo one screw and a nut and the entire middle slides upwards. Got up and did it just to see. It works!



service 101 - RTFM before you fix shit

[Specmaster]

Yep, always a good idea if you have the manual that is, but many times we don't have the manual simply because they are often as rare as rocking horse shit. 

It will also tell you where that left out test point post is meant to be 

[mnementh]

(SNIP)
Properly reassembled:



Now I've RTFM and know there is a zero marker it actually makes sense. 10MHz at 0dBm out of my DG1022Z:
(SNIP)
And on that note I'm going to bed 

Now THAT is one picture that's worth a thousand fucks. 

Well done, my friend. Hope all it needs now is a little touch-up paint and some polish. 

It appears that its prior owner still exists: www.naptech.com

Unfortunately for me, even though they appear to have an amazing location in the forest a little West of Sacramento, their business clearly has nothing to do with my second favorite inactivity but rather their close proximity to wine country & the Napa Valley. 

mnem
"RTFM, bitches." ~ me

[bitseeker]

Congrats on reviving the SA, bd! Looks great!

[URI]

Now I've RTFM and know there is a zero marker it actually makes sense. 10MHz at 0dBm out of my DG1022Z:

Very good job!   
Nice to see this old puppy alive again. Looks great. 

That brings back memories:
When I studied at university the laboratory we students had our practical studies in were equipped with 7000 series Tek oscilloscopes. Were antique in those days already (second half of 1990s) but impressive e.g. with analogue storage capability and -compared to my Hameg 203 (I was very proud of then!)- very good trigger functions.
Being outdated already and huge compared to modern scopes of that era, they had one advantage over other modern scopes of that time:
They didn't have an AutosSet-Button!       

Ideal for learning how to use an oscilloscope from scratch. And let me tell you we had our problems sometimes to get a trace displayed -some experiments where explicitly set up in a way that e.g. we had find out that external triggering was the only way and we had to find or build a suited trigger source.

These Tek scopes were being maintained by one academic assistant over the decades who started to work there when the laboratory was set up with these scopes and retired around 2000 -when then laboratory was re-built and re-equipped.
One reason for that was the change of the professor of the regarding institute and the fact that there would be nobody any more to service them.

[bd139]

I meant to reply to a few posts earlier in the thread. Unfortunately got rather distracted with that SA. Anyway here we go... reply cannon loaded...

@mnementh: Those GF10A's look rather interesting although I'm not sure I can justify one of those for a few inductors. DE-5000 is probably best bang for buck that doesn't look hooky though

Also naptech. Indeed you'd think they sold beds or something. Another vendor that popped up inside there is Avantek who made the yig. Think they are dead now.

@med6753: regarding the RCA scope, that happened when I recapped the D83 HT. It was working but limping before hand but the moment I got my hands in it, I buggered something else. At least it's easy to get to the bits in yours

@GregDunn: Beavis was basically me from the age of about 12-20 and probably now a bit.



@URI: good luck with Keysight. I have had problems with them before ordering small parts. They work it out in the end. Not the most organised of companies at least from the UK when it comes to this stuff as you usually get bounced around for a bit.

WRT your experience with the 7000's. They had them where I worked in the mid-late 1990s with "for indication only". They actually did most of the real work. If traceable measurements were required the HP digital units got used or the engineers just lied. They forcibly levered a huge number of them off the people in the labs. Being located on the other side of the rather large facility, and doing something mostly unrelated by then, by the time the news had spread everyone had intercepted everything. I did walk away with something but I can't remember what. I think it was a Philips PM3217 but can't remember if it was the one I had until a few years back or that was a Yahoo auctions buy. Had soooo many scopes over the years. Really need to keep a lab notebook or something.

@Specmaster: those knobs look pretty good actually. For the money, you can't really beat something made to order of that quality. I'm seriously considering getting some stuff made up.

[Berni]

Very good job!   
Nice to see this old puppy alive again. Looks great. 

That brings back memories:
When I studied at university the laboratory we students had our practical studies in were equipped with 7000 series Tek oscilloscopes. Were antique in those days already (second half of 1990s) but impressive e.g. with analogue storage capability and -compared to my Hameg 203 (I was very proud of then!)- very good trigger functions.
Being outdated already and huge compared to modern scopes of that era, they had one advantage over other modern scopes of that time:
They didn't have an AutosSet-Button!       

Ideal for learning how to use an oscilloscope from scratch. And let me tell you we had our problems sometimes to get a trace displayed -some experiments where explicitly set up in a way that e.g. we had find out that external triggering was the only way and we had to find or build a suited trigger source.

These Tek scopes were being maintained by one academic assistant over the decades who started to work there when the laboratory was set up with these scopes and retired around 2000 -when then laboratory was re-built and re-equipped.
One reason for that was the change of the professor of the regarding institute and the fact that there would be nobody any more to service them.

Back in school i liked to twiddle those old analog Hameg scopes that i found around the place. On purpose leaving all the switches in a state that is as far as possible from getting a stable trace. Sometimes i would then get to see someone try to use the scope and having one hell of a time getting it to do what they want. This made for some really good entertainment when a teacher that thinks he knows everything (But really doesn't) tried to use it in a demo with everyone gathered around (Okay that one was a bit evil, but lots of fun).

[Vgkid]

A power supply I didn't need or really want. But no one bid against me.
Kepco ate25-10.
I will be giving away my cheap/ broken cheap power suplies , and selling my 2 high end ones.

[mnementh]

I meant to reply to a few posts earlier in the thread. Unfortunately got rather distracted with that SA. Anyway here we go... reply cannon loaded...

@mnementh: Those GF10A's look rather interesting although I'm not sure I can justify one of those for a few inductors. DE-5000 is probably best bang for buck that doesn't look hooky though

Also naptech. Indeed you'd think they sold beds or something. Another vendor that popped up inside there is Avantek who made the yig. Think they are dead now.

@med6753: regarding the RCA scope, that happened when I recapped the D83 HT. It was working but limping before hand but the moment I got my hands in it, I buggered something else. At least it's easy to get to the bits in yours
   @GregDunn: Beavis was basically me from the age of about 12-20 and probably now a bit.

@URI: good luck with Keysight. I have had problems with them before ordering small parts. They work it out in the end. Not the most organised of companies at least from the UK when it comes to this stuff as you usually get bounced around for a bit.

WRT your experience with the 7000's. They had them where I worked in the mid-late 1990s with "for indication only". They actually did most of the real work. If traceable measurements were required the HP digital units got used or the engineers just lied. They forcibly levered a huge number of them off the people in the labs. Being located on the other side of the rather large facility, and doing something mostly unrelated by then, by the time the news had spread everyone had intercepted everything. I did walk away with something but I can't remember what. I think it was a Philips PM3217 but can't remember if it was the one I had until a few years back or that was a Yahoo auctions buy. Had soooo many scopes over the years. Really need to keep a lab notebook or something.

@Specmaster: those knobs look pretty good actually. For the money, you can't really beat something made to order of that quality. I'm seriously considering getting some stuff made up.

That was precisely my assessment of the GF10A/LCR106. While overall as a piece of hardware it does give me a raging nerd-boner, I just can't justify the cost even to my own psycho-ass self.

I imagined NapTech as maybe one of the first sleep-study institutes... that's what I get for thinking.

WRT D83 & Beavis gif... Is that how penis fingers was made? Would explain SO-O-O much. 

I burned all my lab notebooks in a paranoid rage after I crashed & burned from working corporate. Probably the only reason I'm not in gitmo.

Back in school i liked to twiddle those old analog Hameg scopes that i found around the place. On purpose leaving all the switches in a state that is as far as possible from getting a stable trace. Sometimes i would then get to see someone try to use the scope and having one hell of a time getting it to do what they want. This made for some really good entertainment when a teacher that thinks he knows everything (But really doesn't) tried to use it in a demo with everyone gathered around (Okay that one was a bit evil, but lots of fun).

When I was in school, that was one of the "pop quizzes" our instructor would lay on us from time to time... he'd deliberately twiddle every scope on the benches beforehand to make it as messed-up as possible, then have us get a specific waveform from our lab circuits (usually a tricky one that wasn't labeled on the board, but that we SHOULD HAVE stumbled across while we were assembling or some point in the circuit that he had specifically gone over in lecture) up on the screen in 5-10 minutes, depending on what he felt was reasonable setup and diag time. When the egg-timer dinged, you stepped away from the bench immediately or you got an X. Sonuvabitch wasn't above unplugging cables from the back of the scope either. 

At the end of the course he explained that the whole purpose of the pop-quizzes was NOT grading... (though I suspect he did use those results as a grading "modifier") but to get us in the habit of turning on, checking and setting up the scope and meters properly for use first thing, every time we sat down... which was something he stressed during several lectures throughout the course without in any way relating this to the quizzes. About a third of us started doing it without even thinking about it while he did his "last class recap" at the beginning of every class. 

A power supply I didn't need or really want. But no one bid against me.
Kepco ate25-10.
I will be giving away my cheap/ broken cheap power supplies , and selling my 2 high end ones.

Yeah, I've amassed quite a collection over the years myself... gonna have to cull the herd here pretty soon. I have more than 20 variable and fixed-voltage regulated PSUs, not including 3 storage bins full of wall-wart & laptop-style PSUs up to ~10A capacity.  And in all honesty, not one of them what I'd consider to be "lab quality" since my Lambda/Veeco dual 40V unit actually caught fire a few years ago.

mnem
*Currently trying to resurrect Franken-Cruiser's AC... AGAIN.*

[Mr. Scram]

I'm in the market for a new power supply myself. I still need one that's accurate, computer controlled and has remote sensing. I missed that last requirement when I bought the last otherwise very nice one. Maybe it's time to finally spring for a HP, Agilent or Keysight one.

[bd139]

After the same. Patiently waiting for an affordable E3632A to go past. They work nicely with a shitty serial USB dongle.

[mnementh]

   
https://www.ebay.com/itm/362336982127

You mean like this one? AS-IS DOA, visible chunk damage, visible water damage, ONLY $313!!! and coming from Israel, so ONLY 4 weeks delivery time!!!   

Sometime around Halloween, you MIGHT receive a box that DOESN'T have a medium-sized rock in it!!!   

Worse yet, you might actually receive the brick of toxic waste shown in the pictures!!! 


Jeezus... talk about putting your garbage up on eBay instead of in the dumpster where it belongs... 


mnem
"Another fine listing by Fuckwits-R-Us !!!"

[Mr. Scram]

   
https://www.ebay.com/itm/362336982127

You mean like this one? AS-IS DOA, visible chunk damage, visible water damage, ONLY $313!!! and coming from Israel, so ONLY 4 weeks delivery time!!!   

Sometime around Halloween, you MIGHT receive a box that DOESN'T have a medium-sized rock in it!!!   

Worse yet, you might actually receive the brick of toxic waste shown in the pictures!!! 


Jeezus... talk about putting your garbage up on eBay instead of in the dumpster where it belongs... 


mnem
"Another fine listing by Fuckwits-R-Us !!!"

To be fair shipping is a large part of the costs, but that doesn't change the fact that the back looks like it has been sitting in salty water. I've seen more items sold from Israel at stupid prices. Either electronics are very expensive there or they're not quite in touch with the market.

[mnementh]

Yeah, but their crazy shipping costs aren't my problem. I didn't ask them to try and sell their burned-up crap halfway 'round the world on MY side of the platform.

They need to try and sell their garbages locally first throw their garbages in the dumpster where it belongs, rather than pollute my fleaBay widdit. 

mnem
*Not in a mood to suffer fools*

[Mr. Scram]

Yeah, but their crazy shipping costs aren't my problem. I didn't ask them to try and sell their burned-up crap halfway 'round the world on MY side of the platform.

They need to try and sell their garbages locally first throw their garbages in the dumpster where it belongs, rather than pollute my fleaBay widdit. 

mnem
*Not in a mood to suffer fools*

If someone halfway across the world buys something from me and complains it is expensive because of the shipping costs I would dispense a heartily laugh at his expense.

[mnementh]

Yes, but you aren't putting garbage up for sale. BIG difference.



Case in point: HP / Agilent 6622A PSU  $66

This is NOT garbage. $78 shipping, yes... but I know how these guys pack sh**. Their rates are CHEAP. Looks like CH1 has an OVP fault, but CH2 appears to work properly.

   

Agilent 6690A $1995

Okay... this one MIGHT be garbage. But fuuuuuu**, man. Lookit the back of that bitch.  *SCHWANNNGGG!!!*   

mnem
No electrons were harmed during the creation and distribution of this post. A great many WERE terribly inconvenienced, however.