Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

Too late, Murphy did notice and Murphy agrees with me that DRL's are infact an important safety factor and if a car is built with them then they should never be disabled. It not as if you have to pay through the nose to have these switched on, they are not massively power hungry items.  Remember, they are for the benefit of other road users and if someone can see you clearly because of them it might save your life in return  because the other person didn't pull out of a side turning right into your path causing a crash, what ever next, refusing to wear your seatbelt? 

Even if you don't care about your safety as a result of being easier to spot, consider the other person and help to protect them as well, geez. 

If someone can't see this blue blob of an SUV under normal daytime conditions I have to question whether they should be driving at all. And in cases of inclement weather or night time I have the intelligence to use appropriate exterior lighting as necessary. I don't need to rely on a computer to make that basic decision for me. And.....to help insure I am seen when lighting is required I installed these auxiliary driving lights.

No such thing as "auxiliary driving lights" for road use. On the front they are headlights or foglights. Less tha 24" above the ground can only be a foglight. On diconnectting DRLs, if you have an accident involving vibility of your vehicle this might be used against you.

From a road/rally racing perspective, where I'd guess these terms originated, Fog lights are specifically 1) yellow/amber and B) placed as close to the road surface as possible to do safely.

The reason for this is because the amber color illuminates objects better when there is visual noise of rain or fog. Placing them low is to try and get the light under the fog layer so it doesn't just reflect off the fog, glaring you to death.

What are referred to as "driving lights" are just that: Additional white lighting positioned similarly to the vehicle headlights to get more illumination where you usually use it for driving. These are often dimmable exactly the same as your regular headlights, while fog lights are usually single filament.

mnem
*lit AF*

[Ice-Tea]

Yokogawa WT1600. These things fetch a pretty high price, didn't quite understand why. I'm starting to, though... It's like the engineers asked:

Nice one.
6ch power analyzer with up to 1MHz BW and 0.1% accuracy (but not both specs at the same time, 0.1% power accuracy @ 1MHz is plain unrealistic). There are not many manufacturers that can get this right, Yokogawa cleary is top notch in this category. And as these are quite specialized, there's neither a lot of them on the market nor significant competition.

Unfortunately only one channel module installed. Would have been double the payday otherwise.

Want one, but I'm absolutely not willing to pay the price tag these things usually have. So don't even think of selling this thing to me

Oh, I'm thinking about it. It's on eBay, outside eBay it's obviously a fair bit cheaper.

BTW.
Doing all these measurements and visualisations isn't the big deal (been there, done that in my first and second job), even less a hassle with todays DSP and MCU computing capabilities. Buy some text book and you'll find all the formulas required for the calculations. Sit down and write some C / DSP code, and make some nice screens to visualize the results. Getting the analog front ends right is some kind of an art.

Kinda figured. It's all just Excel. But unless you've spend a lot of time on it like you have, it'll be easier/cheaper/surer to buy one of these than to pay an engineer for it  And I'm guessing that if you'd have to do it and bill your hours it's gonna be an expensive endeauvour.

EDIT: I'll continue posting nice pictures tomorrow in an apparently fruitless attempt to turn this ship around and have it pointing back to TEA again.

Also: EV's rule suppreme, WAGOs are the ducks guts and fog lights are great.

*ice-tea out*

[factory]

If there is a need for maximum brevity, use BJT.

And Vince, don't you dare to name EITHER transistors OR transformers 'TR' in a circuit diagram!
On the topic of reference designators, any semblace of 'humour' which I might have shown otherwise, is instantly set to ZERO!

Reminder: the three terminal semiconductor devices in question shall be named Q and nothing but Q!
The static magneto-electric converter based on coupled inductors gets the T.

Numerous British Rail items (but not all) had transistors labelled with "TR"  and so did the old Druck pressure calibrator.

Some pictures showing a few examples from a defunct repair company, thanks to waybackmachine, they were the only pics I could find of BR electronics on the web.
http://web.archive.org/web/20090830032437/http://www.richmondrepair.co.uk/transport.html

David

[factory]

Scored a TTI TS3022S 2 channel PSU today from work being thrown out.

Congratulations! The TTi PSUs are nice. I was gifted one from work, too. Mine has a slight bezel chip taken out, 7-segment LED metering, and channel 2  sometimes needs a good virtual whack to start supplying current; the ON button must be toggled a few times before it starts working . But it works very well, as soon as it's running.

I'm now so well supplied with supplies that I've started searching for a higher voltage one, perhaps a 6209A or so.

You might prefer a 6209B, the manual for the A version is unobtainium.

David

[Specmaster]

Too late, Murphy did notice and Murphy agrees with me that DRL's are infact an important safety factor and if a car is built with them then they should never be disabled. It not as if you have to pay through the nose to have these switched on, they are not massively power hungry items.  Remember, they are for the benefit of other road users and if someone can see you clearly because of them it might save your life in return  because the other person didn't pull out of a side turning right into your path causing a crash, what ever next, refusing to wear your seatbelt? 

Even if you don't care about your safety as a result of being easier to spot, consider the other person and help to protect them as well, geez. 

If someone can't see this blue blob of an SUV under normal daytime conditions I have to question whether they should be driving at all. And in cases of inclement weather or night time I have the intelligence to use appropriate exterior lighting as necessary. I don't need to rely on a computer to make that basic decision for me. And.....to help insure I am seen when lighting is required I installed these auxiliary driving lights.

No such thing as "auxiliary driving lights" for road use. On the front they are headlights or foglights. Less tha 24" above the ground can only be a foglight.
On diconnectting DRLs, if you have an accident involving vibility of your vehicle this might be used against you.

From a road/rally racing perspective, where I'd these terms originated, Fog lights are specifically 1) yellow/amber and B) placed as close to the road surface as possible to do safely.

The reason for this is because the amber color illuminates objects better when there is visual noise of rain or fog. Placing them low is to try and get the light under the fog layer so it doesn't just reflect off the fog, glaring you to death.

What are referred to as "driving lights" are just that: Additional white lighting positioned similarly to the vehicle headlights to get more illumination where you usually use it for driving. These are often dimmable exactly the same as your regular headlights, while fog lights are usually single filament.

mnem
*lit AF*

Fog lights over there may well be amber or yellow, they used so here, but I doubt it is the case now. My own car, admittedly is of Czech origin, has built-in fog lights and I can attest to them 100% being white.

[factory]

Nixie DMM update

I replaced both trannies in the trigger circuit. Looked in my stock for trannies with a similar round metallic package. First one I found was a 2N2905A.
Looked up the datasheet. PNP general purpose. current, voltage, hFE, speed... all better than the Germanium trannies.

Checked them with the tester before soldering them on the board, just in case... at the same time checked pinout. Same as the Germanium ones so can't go wrong.

Powered up the thing... no change. Still won't generate a trigger signal. Trigger circuitry still shows zero sign of life.
So...some other component in there must be bad... 

OK, progress !

After some more playing, I felt there was some indication of a capacitive effect : assume the counter is free running. I then short the comparator output to stop it from free running. Now I power off the meter. Then power it back up immediately. Meter wakes up NOT free running. It survived the 2 seconds during which it was powered off. I did that 20 times in a row, never misses a beat. But, if I power off the meter and wait for a short while, just a few seconds, like 10/15, then upon re-applying power, the counter wakes up free running ! Works every time. So there was a pattern there, it seemed.

So I replaced a couple 100nF film caps on the board, see below. One is in the trigger circuit, on the right hand side input, the one solicited by the push-button when using Manual trigger. I assume it must be used to debounce the push-button. So not a very critical application, but well, replaced it anyway.
Second cap, identical one, is the one that does the RC differentiation to generate / derive the Reset pulse, from the output of the trigger circuit. That one I had more hopes about.

Well that fixed it ! Trigger circuit now works as it should, both Manual and Auto modes, and the ramp generator is now back to life as a consequence... which now allows the meter to take measurements !
In short : Vince 1, Meter 0 

However, once I had pulled the caps, I tested them on the Chinese meter, and they were both fine. I also did a leak test with my lab power supply, recreating the sort of voltages that the caps are subjected to on the board... and they don't leak anything. Under 30Volts, one leaks zero, and the other like 50nA....
So not sure what's going on here... maybe the caps as such were not bad... but their solder joints needed some freshening up, and that's what I did when I desoldered them ?

I am tempted to put the old caps back on, and chances are it would still work ! 

I now can't get the counter to free run anymore. Might come back to haunt me soon I bet, but for now, it looks like I was right. The problem was most likely a dodgy reset due to a failed trigger circuit.
We shall see how long it stays working...

So... that means that replacing these two Germanium 2N1305 trannystors with basically the first random silicon PNP I picked in my drawers, a 2N2905A... works just fine ! 
A bloody 2N2905A.... there you go ! 

Those WIMA caps, do they have a part code on them? I seem to recall some were paper based, but not all and BR used them too.


David

[Cerebus]

The reason for this is because the amber color illuminates objects better when there is visual noise of rain or fog.

No, the theory is that yellow light will undergo less Tyndall scattering so will illuminate the fog less (as opposed to illuminating the scene more), thus adding less noise to the environment (Tyndall scattering is inversely proportional to the 4th power of wavelength, shorter wavelengths scatter more).

I say theory because in practice I haven't found that yellow fog lights are any better than white ones. The difference between yellow at ~580nm and the rest of the spectrum integrated up to blue at ~475nm isn't in fact a lot when you additionally take the black body spectrum of ~2500K incandescent light into account which is already on the downslope as it heads toward blue, doesn't really add up to a perceptually significant difference, especially when recalling that light intensity perception is also logarithmic itself.

[capt bullshot]

Yokogawa WT1600. These things fetch a pretty high price, didn't quite understand why. I'm starting to, though... It's like the engineers asked:

Nice one.
6ch power analyzer with up to 1MHz BW and 0.1% accuracy (but not both specs at the same time, 0.1% power accuracy @ 1MHz is plain unrealistic). There are not many manufacturers that can get this right, Yokogawa cleary is top notch in this category. And as these are quite specialized, there's neither a lot of them on the market nor significant competition.

Unfortunately only one channel module installed. Would have been double the payday otherwise.

I'm out. Way to clunky for just one channel, and many measurements are not possible with just one channel. For a price tag that I won't disclose because most probably you'd never speak to me again afterwards, I'd consider it an interesting teardown and other studies object. It's quite a challenge to verify 1MHz power analyzer measurements, requires thought and time, and at the moment I don't have an appropriate rabbit hole

The Voltech power analyzer I bought last year was in the 100EUR per channel ballpark. It's clunky too, and most of the time it's sitting in some corner of the lab. Would be interesting to see if Yokogawa has less drifty analog front ends than the Voltech (their accuracy spec is quite optimistic as far as I was able to verify).
https://www.eevblog.com/forum/repair/voltech-pm3300-power-meter/

[Robert763]

No such thing as "auxiliary driving lights" for road use. On the front they are headlights or foglights. Less tha 24" above the ground can only be a foglight.
On diconnectting DRLs, if you have an accident involving vibility of your vehicle this might be used against you.

One needs to be careful when making definitive statements like "Less tha (sic) 24" above the ground can only be a foglight". While that might be true under, for example, "The Road Vehicles Lighting Regulations 1989", it may not necessarily be true of New York's Vehicle and Traffic laws.

And anyway, if we are talking about "The Road Vehicles Lighting Regulations 1989" the relevant figure for the minimum height of headlamps is 500mm.

I was quoting NY state law

[mnementh]

The reason for this is because the amber color illuminates objects better when there is visual noise of rain or fog.

No, the theory is that yellow light will undergo less Tyndall scattering so will illuminate the fog less (as opposed to illuminating the scene more), thus adding less noise to the environment (Tyndall scattering is inversely proportional to the 4th power of wavelength, shorter wavelengths scatter more).

I say theory because in practice I haven't found that yellow fog lights are any better than white ones. The difference between yellow at ~580nm and the rest of the spectrum integrated up to blue at ~475nm isn't in fact a lot when you additionally take the black body spectrum of ~2500K incandescent light into account which is already on the downslope as it heads toward blue, doesn't really add up to a perceptually significant difference, especially when recalling that light intensity perception is also logarithmic itself.

Okay... that's the how behind it... but functionally, the point is that the usable illumination is better with amber lights when rain or fog creates visual interference.

I too have found that yellow lights don't seem a lot better than regular white headlights. However, a proper deep amber foglight, placed as low as you can without knocking it off, does work better in my experience with off-road rally racing. Also, the apparent brightness of the light is considerably less than those yellow-white "fog lights" except when used as intended; I suspect that perception has a lot to do with the fact it's really quite hard to get fog lights in a proper amber color anymore at most Car Owner Hell type parts stores.

mnem

[Cubdriver]

Scored a TTI TS3022S 2 channel PSU today from work being thrown out.

Congratulations! The TTi PSUs are nice. I was gifted one from work, too. Mine has a slight bezel chip taken out, 7-segment LED metering, and channel 2  sometimes needs a good virtual whack to start supplying current; the ON button must be toggled a few times before it starts working . But it works very well, as soon as it's running.

I'm now so well supplied with supplies that I've started searching for a higher voltage one, perhaps a 6209A or so.

You might prefer a 6209B, the manual for the A version is unobtainium.

David

And a 6515A to get you up to 1.6 kV @ 5 mA - very handy for reforming HV electrolytic caps that have been sitting for long periods.




(The HP 3440A on the right is reading leakage current in µA)

-Pat

[mnementh]

So you did, I thought I did see it before, but like I said, it never hurts to make sure 

I don't think this one's been posted:



Sums it up nicely. Stranded and solid is more common than you might think.

And yet, people have been putting stranded and solid core wires together for over a century using wirenuts.

I'll admit to not liking to do it, and I'll refuse to do it with fine-stranded wire if I can get away with it. But I do know how to do it with the usual coarse-strand stuff pulled through conduit. 




My personal preference is to use a barrier strip, even if just for a couple conductors. What is your opinion of using one of these with a 4-6 pin radial compression crimper?

mnem

[tggzzz]

The reason for this is because the amber color illuminates objects better when there is visual noise of rain or fog.

No, the theory is that yellow light will undergo less Tyndall scattering so will illuminate the fog less (as opposed to illuminating the scene more), thus adding less noise to the environment (Tyndall scattering is inversely proportional to the 4th power of wavelength, shorter wavelengths scatter more).

I say theory because in practice I haven't found that yellow fog lights are any better than white ones. The difference between yellow at ~580nm and the rest of the spectrum integrated up to blue at ~475nm isn't in fact a lot when you additionally take the black body spectrum of ~2500K incandescent light into account which is already on the downslope as it heads toward blue, doesn't really add up to a perceptually significant difference, especially when recalling that light intensity perception is also logarithmic itself.

A related point is that viewing clouds through orange sunglasses (cf neutral) allows you to see  more detail in the clouds. You can see the edges and structure more clearly, which is important for some purposes.

[Cerebus]

Back in the day when monochrome photography was the norm a No 27 yellow filter was de rigueur in a photographer's kit for similar reasons. Obviously the photographer was interested in æsthetics rather than thermals. Of course in both cases one is taking advantage of wavelength related scattering that has already happened rather than trying to avoid it.

[med6753]

No such thing as "auxiliary driving lights" for road use. On the front they are headlights or foglights. Less tha 24" above the ground can only be a foglight.
On diconnectting DRLs, if you have an accident involving vibility of your vehicle this might be used against you.

One needs to be careful when making definitive statements like "Less tha (sic) 24" above the ground can only be a foglight". While that might be true under, for example, "The Road Vehicles Lighting Regulations 1989", it may not necessarily be true of New York's Vehicle and Traffic laws.

And anyway, if we are talking about "The Road Vehicles Lighting Regulations 1989" the relevant figure for the minimum height of headlamps is 500mm.

In addition, "fog lights" tend to have a wide beam while "driving lights" have a narrow beam for distance. These lights fall into the latter category. Regardless of someone's height definitions they really do reach out and provide early warning for the local deer which like to do suicide by car. I also have them biased slightly to the right so as to not blind oncoming drivers  and also the fore mentioned spotting of those 4 legged dumb asses lurking amongst the trees ready to dash out. 

[Vince]

...
I am sorry to be a disappointement... but I will keep saying tranny when I feel ilke it !

So we have two main types of trannies, BJ and FE.
What is E, equal, equally?

FE = Field Effect

[Vince]

Nixie DMM update

...

So I replaced a couple 100nF film caps on the board, see below.

Those WIMA caps, do they have a part code on them? I seem to recall some were paper based, but not all and BR used them too.


David

No markings. They wasted all the available real estate to state " WIMA 0.1 125V ".. twice, just in case we didn't get the message the first time...

[Specmaster]

The reason for this is because the amber color illuminates objects better when there is visual noise of rain or fog.

No, the theory is that yellow light will undergo less Tyndall scattering so will illuminate the fog less (as opposed to illuminating the scene more), thus adding less noise to the environment (Tyndall scattering is inversely proportional to the 4th power of wavelength, shorter wavelengths scatter more).

I say theory because in practice I haven't found that yellow fog lights are any better than white ones. The difference between yellow at ~580nm and the rest of the spectrum integrated up to blue at ~475nm isn't in fact a lot when you additionally take the black body spectrum of ~2500K incandescent light into account which is already on the downslope as it heads toward blue, doesn't really add up to a perceptually significant difference, especially when recalling that light intensity perception is also logarithmic itself.

Okay... that's the how behind it... but functionally, the point is that the usable illumination is better with amber lights when rain or fog creates visual interference.

I too have found that yellow lights don't seem a lot better than regular white headlights. However, a proper deep amber foglight, placed as low as you can without knocking it off, does work better in my experience with off-road rally racing. Also, the apparent brightness of the light is considerably less than those yellow-white "fog lights" except when used as intended; I suspect that perception has a lot to do with the fact it's really quite hard to get fog lights in a proper amber color anymore at most Car Owner Hell type parts stores.

mnem

They also maybe appear less bright due to their wide and flat light beam. When I got my first car, I fitted such fog lights beneath the bumper, and they were indeed yellow. I couldn't say with any certainty if white or yellow is best because, back then (in the 60s and 70s) we did get some real thick pea soup thick fogs and now that I again have a car with fog lights, mounted low down in the bumper, they are white, but we just don't get the fog like we used, thanks to measures to clean up the pollution that various UK Govts have taken over the years. I'm pretty sure the environment is in better shape today than it was in the 70s and 80s, I remember driving a lorry around London in those days and sometimes there would be fog so thick that you just could not see more than 2 car lengths on the North Circular and most of the working day would be spent waiting for the fog to disperse before I could make my first delivery or collection 

[Vince]

WARNING, TEA CONTENT BELOW, RUN AWAY !!!

Got my RM17 glowing Tek scope today ! 

It's past midnight, spent 3 hours on the thing, giving the front panel the usual 30 minute in situ cleaning in the kitchen, so that it's half presentable and so I don't die of unknown germs and bacteria.

Packaging as you can see was... well, I am short of words. I just don't know what's going on in people's brain ?!
I did tell the guy to take his time when packing it, that I was in no hurry, that all that counted was that it was packaged properly and the front panel well protected.
Guy replied yeah sure no worries, and translated that to : " let me tightly wrap the scope with card board, and oh he said to protect the front so I will tape half a news paper over it ".

Luckily it arrived intact, miracles do happen.


Exterior :

- Once the front was cleaned it looked quite decent, happy with it.

- At the back, air filter is inexplicably clean... not complaining.

- There is a cal sticker dated April 1977, so spot on 45 years ! Sure it must be still in cal today ! 
77 is my birth year so I am not going to say the cal is old, because that would mean I am old too, and I don't feel all that old ?! 

- The power socket is... hmmm...  well you can see for yourself. Guy soldered wires to all 3 prongs then wrapped them with black electrical tape, which was well melted / cooked all over the prongs.
It was not a lot of fun cleaning that mess, but had to if I wanted to plug the thing and play with it... I managed to get it back to a decent enough shape. 


Interior :

- Fan looks big ass, different looking and larger than the one in its 317 bench top counter part. Fan was almost seized, could barely turn the blades by hand, not good at all. Dropped a bit of machine oil in the rear bearing and onto the front on the shaft. Exercised the fan by hand for a bit... not much improvement 

- As I had already seen on the sellers pics, it's very dusty, and a thick disgusting layer all over the tubes, but no rust. A good wash should make it all nice and shiny I think, not worried at all.

- As I saw on the sellers pics again... there was a tube missing. Was a 6DJ8. Pinched one from one of my numerous type 317... I figured it's only fitting for a type 317 bench top to donate an organ to help resurrect its rack mount brother ! 

Electrical / Test drive :

- Fan : it did start up somehow, but as expected very, very.. very... slowly. Was rotating at like I don't know... 10rpm tops ?! ... while making a horrible noise, complaining like hell... but hardly surprising.
However...it soon started to improve, progressively getting better and better, and after only a couple minutes or so, it was now rotating super fast, smoothly, no weird noise anymore... like brand new ! 
I guess the oil I put, must have progressively found its way where it needed to go, and it eventually was able to do its job 
Fan is freaking loud though ! Oh my goodness... it's like a small propeller aircraft taking off !
I don't know if that compared to the old HP gear that are notoriously loud too... as I don't have old HP stuff to compare it with.
But it's... TEN TIMES louder than a normal / bench top type 317. Well at least the thing is weeeeeell cooled down, unlikely to overheat ! 


- Controls : I noticed the AC/DC input coupling switch is stuck. Need to investigate that.

Fire up : looking real bad.... no sign of life from any of the controls, and the CRT looked cooked : all it could do was display some green "clouds"... a bit depressing...
However after an hour or two warming up, and me playing with every control, it progressively was able to do more and more stuff, but mostly completely weird and wonderful, psychedelic things. Things you would not even guess a scope could even do. It was... mesmerizing. Great stuff if one just needs a light show in the living room to amuse clueless friends... but not so good if you want the scope to do what a scope is supposed to do... 
But the more it was warming up, the more I was playing with the knobs... the better it got. After 2 hours playing with it, its condition seemed to "stabilize", and I could now start taking notes of what worked and what didn't.  So here goes :

- CRT / middle section of the cabinet : excellent. Clean bright sharp trace (picture fails to depict its sharpness sadly, but in the flesh it's excellent), that's stable and doesn't fade when hot. It's solid.
Only little "issue" I noticed is the focus control : it has bugger all effect. If you set it half way it gives you a sharp trace no problem, however if you turn the knob side to side it baaaarely goes out of focus. It is incapable of making a thick blurry trace, not even remotely. So I guess something must be amiss somewhere...

- Right side section : trigger works perfectly. Sweep and time base work impeccably too, and the amplifier is still well calibrated, a first glance. If it needs calibrating then it can only be very minor. Baseline is excellent.

- Left side of the cabinet : calibrator output is perfect. Checked it on my Combiscope: stable signal, sharp square, frequency spot on, 980Hz or so, and amplitude is spot on, on all ranges. Combiscope reads 1% high but plenty within spec and well, the automatic measurements aren't even that accurate on that scope to begin with so... I will say the old Tek is spot on.
So I could use the calibrator output to test the scope, so that's what I did.

The problems in this scope appear to be concentrated on the vertical amplifier. It was all over the shop at first, refusing to display a trace at all 99.999% of the time. That was mostly due to the red uncal knob of the attenuator that was super scratchy. Also, the DC balance control was completely out of whack. So once I had exercised the uncal knob a bit, and gone through all of the attenuator settings twice, to adjust the DC balance... I was able to improve things dramatically. Now, it can display the calibrator square wave beautifully, and most ranges are calibrated spot on 

There are mainly 2 problems to fix, on some ranges :

- On ranges 20 / 2 / 0.2 and 20mV / DIV settings, it fails to display the square wave. Instead, it displays sharp negative and positive pulses. That is, the square wave is like going through an RC "differentiator"  circuit. a parasitic one of course ! Must be a simple fix I guess... broken connection, bad contact somewhere...
Since it affects only all the 20/2 etc ranges, the problem must be localized to a decade selector, hence should be able to narrow it down quite a bit in the schematic, I would think.

- On the 3 most sensitive ranges, 50 / 20 / 10mV, which are all AC only, the amplitude of the trace is way too small ! Like 2 or 3 DIV instead of 10, something like that. Also, the trace incessantly moves up and down, like a roller coaster. So me think the AC coupling cap is dead, and passing only part of the signal. Again, should be an easy fix. 



Conclusion

Bought it for only 15 Euros, 22 Euros delivered, sold for parts.... but... it's a WINNER, I say !!!   

1AM already ! Have not even eaten anything since breakfast !    Let's cook something quick to fill that stomach a bit, and off to bed !!!

Have a good night ! Fasten your seat belt and turn on all your lights please  !!! 

[Vince]

....

[Cubdriver]

WARNING, TEA CONTENT BELOW, RUN AWAY !!!

Got my RM17 glowing Tek scope today ! 

It's past  midnight, spent 3 hours on the thing, giving the front panel a the usual 30 minute in situ cleaning in the kitchen, so that's it's half presentable and so I don't die of unknown germs and bacteria.

Packaging as you can seee was... well, I am short of words. I just don't know what's goign on in people's brain ?!
I did tell the guy to take his time with packing it, that I was in no hurry, that all that counted was that it was packaged properly and the fornt panel well protected.
Guy translated that to : " let me tightly wrap the scope with card board, and oh he said to protect the front so I will tape half a news paper over it ".

Luckily it arrived intact, miracles do happen.




Bought for 15 Euros, 22 euros delivered, sold for parts.... but... it's a WINNER, I say !!!   

1AM already ! Have not even eaten anything since breakfast !    Let's cook something quick to fill that stomach a bit, and off to bed !!!

Have a good night ! Fasten your seat belt and turn on all your lights please  !!! 

Nicely done, Vince!! Congrats on a good score.  Looks like the shipper went to the same packing school as the guy I bought the Electro Instruments meter from.  Cushioning?  We don't need no steenkin' cushioning!



-Pat

[med6753]

There are mainly 2 problems to fix, on seom range :

- On ranges 20 / 2 / 0.2 and 20mV / DIV settings, it fails to display the square wave. Instead, it displays sharp negative and positive pulses. That is, the square wave is like going through an RC "differentiator"  circuit. a parasitic one of course ! Must be a simple fix I guess... broken connection, bad contact somewhere...
Since it affects only all the 20/2 etc ranges, the problem must be localized to a decade selector, hence should b able to narrow it down quit a bit in the schematic, I would think.

- On the 3 most sensitive ranges, 50 / 20 20mV, which are all AC only, the amplitude of the trace is way too small ! like 2 or 3 DIV instead of 10, something like that. Also, the trace incessantly moves up and down, like a roller coaster. so I think the AC coupling cap is dead, and passing only part of the signal. Again, should be an easy fix. 

The 20mV, 200mV, 20V decade range is always the problem child in Tek attenuators. Deoxit will fix it. It will probably the fix the issue on low range AC too.

Looks like you got a good deal. 

[med6753]

Nicely done, Vince!! Congrats on a good score.  Looks like the shipper went to the same packing school as the guy I bought the Electro Instruments meter from.  Cushioning?  We don't need no steenkin' cushioning!



-Pat

WTF  Even the cat is pissed because you had to rip the box down denying it the opportunity to sit in it. 

[MaxFrister]

Somehow I never seem to have the correct bnc adapter

[Cerebus]