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DIY Stompboxes => Building your own stompbox => Topic started by: LightSoundGeometry on November 17, 2015, 05:57:16 PM

Title: new oscilloscope help
Post by: LightSoundGeometry on November 17, 2015, 05:57:16 PM
The oscilloscope is new to me, I have only one introductory lab so far and that was with a function  generator. Basically to get to know the knobs and switches etc.

I made a short video - any advice or help is greatly appreciated

Title: Re: new oscilloscope help
Post by: LightSoundGeometry on November 17, 2015, 06:43:02 PM
I need a function generator..figured it out lol 
Title: Re: new oscilloscope help
Post by: deth502 on November 17, 2015, 08:53:50 PM
you are an antenna. what you get when you touch the probe is a 60hz signal from the electricity all around you.

"im on dc because im testing a dc circuit" no. "ac" is ac coupled, so any dc component ot the signal being measured will be ignored. "dc" is dc coupled, so the waveform on the screen will include any dc offset.

at this point, you should be concentrating on the trigger level, time base (sec/div), and amplituude (v/div).

the "flashing" is the beam traveling across the screen. it does that on EVERY setting, but through persistence of vision, at a certain speed is appears as a solid line.

Title: Re: new oscilloscope help
Post by: GibsonGM on November 18, 2015, 07:34:26 AM
"Visual analyser" is freeware, and contains an audio-frequency function generator you can output from your sound card...or make a quick 555 astable circuit to see square waves. There should be a calibration port on that, too, that will give you a square wave of known voltage/freq....is there a manual?  If not, get one online! 

Be cautious, LSG...if you input too large a signal on too low a range, you may pop an internal component, making it necessary to disassemble the unit to find it.  That can be interesting (many pins!!!).   Avoid that at all costs.    This is where the manual is helpful....you'll find those slow settings, where you watch the beam like a heart monitor, are not that useful ;)

Title: Re: new oscilloscope help
Post by: vigilante397 on November 18, 2015, 11:25:10 AM
Before you try the popular hands-on "push buttons until things work" approach, I would second the recommendation to read the manual. I found the manual for the LS8022 with a quick google search and it's a very manageable 28 pages. Good luck ;D Once you get the hang of them oscilloscopes are a remarkably useful tool, and knowing how to use one to debug a circuit is a very desirable skill.

http://assets.tequipment.net/assets/1/26/Documents/LS8050_manual.pdf (http://assets.tequipment.net/assets/1/26/Documents/LS8050_manual.pdf)
Title: Re: new oscilloscope help
Post by: Kipper4 on November 18, 2015, 03:08:52 PM
Congrats on getting an Oscope LSG.
Very useful for comparison of input signal to outputs signal peak to peak voltages and seeing exactly what your circuit is doing to the signal vis a vis clipping for example. Symmetrical clipping,Asymmetrical clipping.
Also for DC voltages.
There are many good videos on tricks and things on you tube too.
A manual is a must then you will know the scopes limitations too.
I made some homemade probes using those little clip on things, can't remember what they're called. As well as the ones I bought for it. Mines a 20hz-20khz scope.
I don't use it very often but I wouldn't be without it.
Have fun.
Rich

Edit
Mini grabbers apparently:)

http://www.ebay.co.uk/itm/HT321-18pcs-lot-mini-grabber-SMD-IC-test-hook-clip-jumper-probe-5-colors-/131637566817?hash=item1ea635dd61:g:qYgAAOSwqu9VEVeX

Not affiliated just so you know what I'm talking about
Title: Re: new oscilloscope help
Post by: slacker on November 18, 2015, 03:33:29 PM
This guy has some good scope tutorials https://www.youtube.com/watch?v=OFGm-Pel4Hg&index=4&list=PL746BF38BC2E068E0 (https://www.youtube.com/watch?v=OFGm-Pel4Hg&index=4&list=PL746BF38BC2E068E0) well worth a look.
Title: Re: new oscilloscope help
Post by: LightSoundGeometry on November 18, 2015, 04:56:27 PM
right on, got the PDF docs on the DL

anybody have any opinions on the cheap chinese FG  you see on ebay for 20 bucks or so? the youtube reviews are a mixed bag of good and bad. I might try that freeware program.

thanks guys
Title: Re: new oscilloscope help
Post by: Kipper4 on November 18, 2015, 05:37:21 PM
Here's an idea LSG
Build one.
RG Keens quick and dirty oscillator is a good place to start.
Also Sam Hay  has a good one too. I'll have a gander,see if I can find it.
Both are low parts and always handy to have when testing and probing circuits.

Edit
My mistake it was Merlin Bs
Title: Re: new oscilloscope help
Post by: Kipper4 on November 18, 2015, 05:40:33 PM
Here you go buddy

http://www.diystompboxes.com/smfforum/index.php?topic=83930.40
Title: Re: new oscilloscope help
Post by: GibsonGM on November 18, 2015, 05:53:52 PM
I use RG's Q&D all the time.  A really nice build would be the generator that Merlin came up with, over at his "Valve Wizard" site!  I want to put that together when I have time.
Title: Re: new oscilloscope help
Post by: Kipper4 on November 18, 2015, 07:07:43 PM
I have both the Q n D and Merlins in the same box.
Switchable so I can choose which one is output.
Title: Re: new oscilloscope help
Post by: LightSoundGeometry on November 18, 2015, 07:35:35 PM
oh wow..Time to burn me a kipper and get prepared to start a new project  8) :icon_mrgreen:
Title: Re: new oscilloscope help
Post by: Kipper4 on November 18, 2015, 08:10:38 PM
No no no no no don't burn it. Smoke it real slow. So you get a good depth and flavour, then savour that satisfying taste.
Scramble some eggs and toast a wedge of bread baste with butter. No nam by lambs margarine mind.
NOW you got it.
Breakfast kippers.
🤓🐟
Title: Re: new oscilloscope help
Post by: vigilante397 on November 18, 2015, 11:57:22 PM
Quote from: LightSoundGeometry on November 18, 2015, 04:56:27 PM
anybody have any opinions on the cheap chinese FG  you see on ebay for 20 bucks or so?

I have a Chinese function generator I got from eBay for around $60, and I haven't found anything to complain about yet. Testing it with my oscilloscope has shown that it's accurate (either that or they are both off by exactly the same amount :P ). I looked into building one, but using the ones at school made me want a relatively nice one with a lot of functionality. But how much you spend on it should definitely be proportional to much you really think you'll use it. If it's just going to be an occasional thing and just for testing pedal functionality, I would highly recommend the Quick and Dirty.

Skimmed my eBay history and found the one I bought:

http://www.ebay.com/itm/291250697392?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/291250697392?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)