First oscilloscope, first set of probes now what?

[Redcat]

Guess who has also a nice old 2215A  . Good choice  . It's a good beginner scope (if you want an old analog scope).

Yes the Teks have a different "feel" than other (old) scopes. A lot of plastic knobs  . They have nice functionality compared to other and a nice layout. Don't expect this feeling from a modern scope (especially not from cheaper ones).
Be careful, the knobs are not as robust as you think. It shouldn't take too much force to rotate them, or they can break (they are over 30 years old now in most cases).
You may have discovered that the 2215A has a second time base and you can access it by pulling on the time base knob and rotating to the right. But I would suggest you to download the handbook pdf (you can find it for free on different places, there is a operators manual and a repair manual), to learn more    .

Try an Arduino to get into MCs, it's an easy way nowdays and you can use it with a breadboard and there are a lot of modules for it availiable.

The candle was a quick idea. I had one laying around and always wanted  to look at it  - did just try.
Of course it can't be used anymore as a candle light as I had to cut it open, but it was fun.
I was once told, that it is playing music, but instead of a speaker it has an LED. Don't know if it's true.
Maybe the scopes load alters the candles output a little.
Edit: I have to correct me, the frequency is really altered (between 2kHz and 3kHz at my candle) so could really be high pitch music  (could not reproduce the dc offset spikes...hmm).

And here is the link to the video edy mentions about grounding ( ):

Have fun :-).

[GiskardReventlov]

@edy great detailed instructions, just what I need, will report back at some point. I will check out that video.


@Redcat, good call on treating the knobs carefully. I am converting the pdf manual I found to epub. I'm at the 90% mark but the last 10% will be slow since I want to preserve the graphical elements from the original and I want to rid them of noise from the bad scanning. As for mC I think I will try atmel stuff, simple stuff, cheap stuff.

I could not find the candle but I have lots of other things to try.

[Redcat]

Yes Atmel  . I used them in many projects (ATMega8), and you can get them in all sizes and DIP or SMD. You  need basically nothing to make a little MC circuit with them, because there is all build in. Try out Bascom, it's a Basic language which is far more easy than C or ASM for a beginner. When I remember correctly it was for free use up to a 2 kB program (many years ago it was 4kB), more than you need for a little project.
The Arduinos use also Atmels  .
Ok, you have the manual, this is good  . The scanning is not so good, I know, but at least we have one (I printed my out and made a book). 

[edy]

Here is what I mean about using 1kHz calibration out on channel 1 and then taking a reading off an RC filter for channel 2. Notice that when the RC is not hooked up, you get a clean square on channel 1. As soon as the RC is attached, the square gets messed up although you can see channel 2 is a lot more of a decay/rise time effect.

Anyone have any idea how to isolate the square wave more so as not to be influenced by the RC?

[edy]

By the way, I used a 1k Ohm resistor (color code brown-black-red-gold) or 1 0 x10 which is 1000 ohm.
And the cap is 104 which means 10 x 10000 or 100000 or 100,000 pF which is 100 nanoF.

Plug that into RC time calculator and you get 0.0001 seconds or 0.1 msec to get to 63%, 0.16 msec to get to 80%, and 0.23 msec to get to 90% of my peak voltage. My square is 1kHz freq meaning the high is 1/2000 of a second or 0.5 msec and the low is another 1/2000 or 0.5 msec for a total cycle from peak to peak of 1 msec or 1/1000. So you can see the curve reaches 90% of the height in about half of the square high, and decays the same way.

[katzohki]

I agree with what some others say about looking at some audio signals. Go down to the 99 cent store (if you have them in your area) and buy some cheap audio patch cable, or even headphones. Strip them so you can get at the wires and use them to look at audio signals!

[hamster_nz]

Anyone have any idea how to isolate the square wave more so as not to be influenced by the RC?

The problem is that their is too much load the calibration output. The output impedance is of the order of maybe 500 Ohm (well on a PicoScope 6400 USB it is 600 ohm), 

Try using 10k R and scaling the cap to suit.

[GiskardReventlov]

@AG6QR, I hooked up my probe to the mp3 player headphone jack but I didn't see anything that look like audio. I see only the 60Hz.  I probably did not connect things correctly. Do I need to push the audio through a circuit on the breadboard?  I connected the scope probe directly to the headphone wires by clipping the probe tip to one wire and the ground clip to the other.

@edy, I'm taking notes and appreciate the detail.

@Redcat, are there regular maintenance tasks that are typical for these scopes?  What hardware programmer do you use for atmel? What dev. tools do you use? I will have a look at Bascom.

@katzohki, yep, had a crap pair of headphones for a cell phone.

[Redcat]

Hi GiskardReventlov,
As beginner you shouldn't worry too much about the inside of the scope (for calibration or repair you need a little more knowledge and tools), but it is good to always take the front cover on if you don't use it and keep it clean. Not much to do.
If you don't use it for longer, there can be some corrosion or bad connection inside the pots/knobs/switches, so you should use it from time to time to keep it working (or at least turn the knobs...this may be the reason why your knobs are a bit stiffy).

For the Mega8 I build the programmer cable myself. It was basically a parrallel port (printer...) cable with some resistors in the right places going to the programmig pins of the MC.
Very basic but it works. But you can buy a cheap Atmel programmer (or programmer cable). This may be better for your need.

I mainly used Bascom and for some software communicating with the MC I used also Delphi (I think the last I have is Delphi 2006) to make some PC software for this .
But with a modern windows system and the missing COM and LPT ports on a computer it is nowdays not as easy as it was some years ago.
But If you use an Arduino it's easy with the USB connection.
For the basic "Hello World" application which is in MC world a blinking LED, you don't need more than the Atmel (ATMega/ATTiny), the programmer (or cable), 9V battery, a voltage regulator (5V - like 7805, and maybe 1 or 2 additional caps - but you don't need), a resistor and the LED and something you mount this (breadboard or PCB). Not many parts - simple made.

Could you post an image, how you connected the scope to the cable?
That your old headphone cable didn't work may be a problem with the cheap headphone cable and not your fault. I once cut some headphone cable (needed it for some application) but couldn't solder it because it was crap. Problem is, you might not get the GND contact  (shielding), only the left and right channel signal line (you need to probe one channel signal and the crocodile clip to the GND, not booth the channels). So there are 3 wires inside for stereo and 2 wires for mono. Try to probe  the cable with your DMM, which contact of the plug goes to the end of each wire. My recommendation would be, take a piece of 2 wire cable and a 3.5mm plug and make yourself a cable. Cut an audio patch cable may also be ok (may be of higher quality), but I don't have one to try.
The long headphone cable works like an antenna that picks up the 50/60Hz line frequency, thats the reason why you see this signal.

Good luck 

[GiskardReventlov]

so you should use it from time to time to keep it working (or at least turn the knobs...this may be the reason why your knobs are a bit stiffy)

Yes the first time I turned the time/div knob it was stiff and since then it turns easier but it's firm and good.  Very good force feedback.

But you can buy a cheap Atmel programmer (or programmer cable). This may be better for your need.

This is what I intend to do.

For the basic "Hello World" application which is in MC world a blinking LED, you don't need more than the Atmel (ATMega/ATTiny), the programmer (or cable), 9V battery, a voltage regulator (5V - like 7805, and maybe 1 or 2 additional caps - but you don't need), a resistor and the LED and something you mount this (breadboard or PCB). Not many parts - simple made.

Simple == Good.

Could you post an image, how you connected the scope to the cable?

Yes, though not much to see, I will test continuity as you recommend and find out what wire connects to what tip.

That your old headphone cable didn't work may be a problem with the cheap headphone cable and not your fault. I once cut some headphone cable (needed it for some application) but couldn't solder it because it was crap. Problem is, you might not get the GND contact  (shielding), only the left and right channel signal line (you need to probe one channel signal and the crocodile clip to the GND, not booth the channels). So there are 3 wires inside for stereo and 2 wires for mono. Try to probe  the cable with your DMM, which contact of the plug goes to the end of each wire. My recommendation would be, take a piece of 2 wire cable and a 3.5mm plug and make yourself a cable. Cut an audio patch cable may also be ok (may be of higher quality), but I don't have one to try.

I understand you, good info, will figure it out.

The long headphone cable works like an antenna that picks up the 50/60Hz line frequency, thats the reason why you see this signal.

Yes, I do wonder how it effects us to be bathed in this.  I think our operational freq. is 8Hz  (Scheuman resonance??).

[Redcat]

Here are some additional MC links for you to look at:

Ok you will buy the programmer  but here is the mentioned link to the programmer cable (in german):
http://www.dieelektronikerseite.de/

(Image is from this website)

Bascom (the demo Version link with 4kB is on the bottom):
http://www.mcselec.com/index.php?option=com_docman&task=cat_view&gid=99&Itemid=54

There was a very nice Bascom/Atmel beginners workshop website too, i sadly can't find it anymore (this was my favorite MC learning website when I first used MCs like 15 years ago).

At university we used much older MCs and ASM, this was a real pain...and the ATMega8 was heaven in comparison.

A simple LED project is always  good start  .
As I understand, you don't want to use an Arduino, but there are also some nice other simple Atmel developer platforms availiable, like "MyARV"...
Or If you can solder a little (you should lern  ), build your own board like you want.

I understand you, good info, will figure it out.

I think you will easy work out whats wrong with the cable  .
Sorry for my english  .

Yes, I do wonder how it effects us to be bathed in this.

Yes there is so much electronic stuff around us with all kinds of emission - can't be healthy  .

[katzohki]

Did you try playing some MP3 files? You're not going to see anything on the audio jack if it's not playing something.

[lapm]

Some of those cheap headphones uses some sort of super cheap cable. seems to have some sort of coating that makes soldering next to impossible. If i would need to measure audio, i would probably go and get connectors and hook up directly to those..

[GiskardReventlov]

@Redcat,  your english is fine, better than my german by lightyears^*. I will check those links and myarv. I got an atmega32 to play with and will post something in the other section of this forum later.

@lapm, I didn't have to do any soldering, I just pulled off the ear piece and strip the wires


*_{I want to learn german, I will start by learning to swear at electronics in german, won't offend anyone, well unless they understand german}

[edy]

You should look for youscope.wav or oscillofun.wav with Google and set your CRO in xy mode. Then just output left to channel 1 and right to channel 2, connecting ground common to ground. Here I did it with my cellphone playing a YouTube version of those demo audio files to an xprotolab:

 

[GiskardReventlov]

I've got some 555 and some 741 opamps so will try some of the other suggestions. There's also an interesting circuit w2aew, in the "How much bandwidth do I need" video. I like that circuit because I know exactly what should display on the scope. (Correction: the correct circuit is in the follow up video to this one)

I got the right jack and looked at the audio, I then set to "Both" and looked at alt, add and chop with ch.1 on the "probe adjust" point and ch.2 on the audio.  That's an interesting thing to see.

One of the main reasons for this post was to make sure the scope's working correctly and it seems to be fine. And that's a bit of a relief.

I'll report back here again as I progress through the other examples.

I had saved an old CRT stand, the kind that clamps on to the table/bench and swivels. This one is really old and built like a brick s**t house.  It was designed to hold those old monster 19" crts that weighed 60-70 pounds. It has brass bushings and is simple and I could never get rid of it just because I admired how it was built.  It now holds my scope above the bench and swivels and saves bench space!  It has u-shaped rod that extends forward so this long scope fits on it perfectly. The u-shaped rod is bent vertically at the outward side so the scope handle rests against that and prevents any sliding. I knew someday I'd find another use for that thing!