My first Oscilloscope!

My father had a small repair shop in the early 80s and had bought this Oscilloscope for his technician.
It ended up in storage for years and he recently gave it to me as he knows i've taken electronics as a hobby of late.
So It is about 30 years old.

I am really a total noob at using these things, but fortunately I have the operating manual!
I hope some of the more seasoned techies here might give me some insights or starter tips about this machine.
I also would like your opinions on this particular oscilloscope. Is it good, bad ? Missing some key features?

( its dusty )
http://i1204.photobucket.com/albums/...ps4ea340ff.jpg

It has all kind of connections, some of which I am not sure about what they do ( I havent read the manual yet but i will )
http://i1204.photobucket.com/albums/...ps9df248d7.jpg
http://i1204.photobucket.com/albums/...psa80bdb2f.jpg
http://i1204.photobucket.com/albums/...ps1ee8f6d2.jpg

I tried powering it up and It shows this line, does not seem totally normal, maybe it will require some calibration. ( Just noticed the trace rotate knob on the back, thats probably it! )
http://i1204.photobucket.com/albums/...ps0b393df0.jpg

Main problem It has is that it came with only one probe, which is broken...
http://i1204.photobucket.com/albums/...ps79b2f179.jpg

It must have come with 2 probes initially but the other one is lost in the abyss of the ages.
I need to shop for probes first thing I guess, Or repair the one I have, it is broken on the connector. Does not seem to be possible to use the original connector but I think they sell connectors like that at my local store.

Another question is, do I really need 2 probes? ( for monitoring reference voltage or something? ) Or I can do pretty well with one for now?
Anyway, pretty excited about this machine. Any input to help me start up with it is appreciated :)

Edit: I found out it is a 10mhz oscilloscope and i think I am going to order these probes!
http://www.ebay.ca/itm/40MHz-Oscillo...item2a14dcd427

That's the way mate!

Those old "cro's" last for ages, used a similar type back in the day when stting up battery charger boards. That is going back about 7 or 8 years now, but I think I still have the setup sequence in my toolbox at home.

How many MHz is that? I use a tektronix 2236 which is 100mhz.

It is 10mhz :p

but can it play tetris?

It's got enough bandwidth for a raster, and it has a Z-input..

So yes, it could. :P

Well, I tried using this oscilloscope with my brand new probe and so far my impression is that the machine is faulty :(

I bought a cheap adjustable oscillator from ebay. http://www.ebay.ca/itm/400292172818?...84.m1439.l2649
Connected it to an external regulated 5v PSU. The oscillator seems to work, I measure 2.5VDC with my multimeter on the clock output, as is normal with oscillators.
http://i1204.photobucket.com/albums/...psf4d5593f.jpg


But when I connect it to the oscilloscope I need to set the zoom at 10mv/division before I see anything. And here's what I see.
http://i1204.photobucket.com/albums/...ps7371a734.jpg

Pretty funky uh? Looks like the footsteps from some alien bird.

There is a X5 zoom function on the machine. This part does seem to work properly, heres what it looks like zoomed.
http://i1204.photobucket.com/albums/...ps2bf332cb.jpg

I also tried measuring some clock and datalines from my GameGear. I dont remember which was shown in this picture but im getting double the waveform!!
Once again I need to set it to 5-10 mV/division before I see the wave properly. Using channel 1 or 2 produces the same results.
http://i1204.photobucket.com/albums/...psda2308b4.jpg

The SECS/DIV dial also seems to misbehave as it does not give consistent results when I move it around and return it. Although this might be dirty contacts.
Im pretty sure this thing has some pretty serious issues but I wish I had access to a known good oscilloscope to learn how to use it properly.
What do you guys think?

Time portion works there ?

The time portion (SECS/DIV) seems to work, although I cannot say how exact it is as I do not have a precise and reliable waveform generator.

Also, some more info:
It says " Maximum input voltage 500v peak ac of dc" in the manual.
The probe was set to x10
I tried changing the coupling to GND,AC,DC it did not change anything in the waveform.
I have a feeling this thing is a dud.

In the meantime I also found this thing in the local kijiji ads, good deal?
http://quebec.kijiji.ca/c-acheter-et...AdIdZ497216595

When the waveform is not changing there's likesy something messed up in the input stages. Two traces can indicate a signal that has two relatively long but alternating states, though for a digital signal there should never be such intermediate step, only top and bottom...

That one in the link looks good, no idea if its worth it or not though. 100MHz bandwidth is plenty to mess around with though, I would like that much myself :P

Man, what an awesome addition. I was obsessed with getting an Oscilloscope a few years back. I had been convinced that I would find something measurable and consistent with the frequencies of output from each console that could go into their respective spec sheets. It turned out it was already common knowledge that FM had a higher range of frequencies that it could reach so I gradually lost interest. I still would like to know what an oscilloscope would tell me about the outputs though.

Nice find! Playing with your first scope is always lots of fun; not much exists these days that looks as neat as the bright green low-speed phosphors on a good old scope.

I got this guy for free a few years ago: http://www.youtube.com/watch?v=Wnb-LTGWwGM

Quote:

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Originally Posted by TmEE

When the waveform is not changing there's likesy something messed up in the input stages. Two traces can indicate a signal that has two relatively long but alternating states, though for a digital signal there should never be such intermediate step, only top and bottom...

That one in the link looks good, no idea if its worth it or not though. 100MHz bandwidth is plenty to mess around with though, I would like that much myself :P

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I think you are right about the two trace explanation. The waviness is possibly explainable by the fact that maybe i had ground disconnected. Dont quite remember, i too these pictures a couple weeks ago and tried with both ground connected and NC

Well, I actually went and bought that 100mhz leader CRO :p Im just back home with it. I haggled it down to 125$, it has two new 100mhz probes and the guy confirmed it was fully working, he made a small Demo at his place, which was 5 min drive away from my place. It also has a built in oscillator for calibration. I will try it and comment back on it.

@sheath: Yeah im pretty enthusiastic about it. I want it mostly for modding/repair as you guessed.

@bibin. Wow, free you say? This looks like a high end model.

Well, new oscilloscope apparently works great! I have not tested everything but hey Im just starting out with those. One cool thing Is I got the User and Service manual with it :)
Volts and time division all match with what im measuring and it locks automatically on the waveforms, which is great.
The other one really has some issues, I will keep it around and maybe try to fix it eventually. Maybe it needs recap? After 30years+ that would not be too surprising.
Anyway here's my new machine:
http://i1204.photobucket.com/albums/...ps16e862da.jpg

I am now measuring ripple noise in the 5v rail of my heavily modded game gear. There Is about 100mv p-p ripple in the rail. Is this considered a lot?
The picture does not do it full justice, its more detailed than this in truth. This is at 20 mv/div setting.
http://i1204.photobucket.com/albums/...ps31ee3cad.jpg

Here the sound output channel background noise. Its pretty noisy. Still at 20mv/div
http://i1204.photobucket.com/albums/...psaf21784f.jpg

Quote:

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Originally Posted by evildragon

How many MHz is that? I use a tektronix 2236 which is 100mhz.

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It sounds as though we may have a similar oscilloscope mine being an older model.
http://img689.imageshack.us/img689/4474/x4yt.jpg
This is an 8mhz single generated from the "special" pwm mode that many avr chips have. In this case it was an atmega328p which was in an arduino uno.

100mV is a ton of ripple, good stuff has less than 10mV. And audio lines should have almost none. My latest-greatest sound mod that I am still working on has ripple and noise in µV scale :3

Quote:

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Originally Posted by TmEE

100mV is a ton of ripple, good stuff has less than 10mV. And audio lines should have almost none. My latest-greatest sound mod that I am still working on has ripple and noise in µV scale :3

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Hehe, that's what I thought. My game gear audio was not this noisy until I connected the SMSFM board to it. I will need to find ways to reduce this. Caps between power and ground and maybe some inductors I imagine.

On a side note, I measured the period of the lower frequency oscillation on my GG sound output with the oscilloscope and calculated the resulting frequency and obtained pretty much exactly 60 hz (60.6), the frequency of the AC power line. I find this a pretty good demonstration that this oscilloscope is quite exact and well calibrated.

Oh, and can't wait to learn more about that new audio mod :)

I'll not make fuzz about it until its finished. I will tell you its name : Ludicrously Overkill Audio MODification

Quote:

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Originally Posted by sega16

It sounds as though we may have a similar oscilloscope mine being an older model.
http://img689.imageshack.us/img689/4474/x4yt.jpg
This is an 8mhz single generated from the "special" pwm mode that many avr chips have. In this case it was an atmega328p which was in an arduino uno.

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Hmm, it's possible. Here's mine.

http://img.photobucket.com/albums/v3...0.jpg~original