Oscilloscope Noobie

[Decko]

Hi Tagers,

Just picked up an O-scope.

Hitachi V-660

I wanted to take the guess work out of troubleshooting my amp builds.

I do not know the first thing about using O-scopes. I plan to scour the web for the users manual.

Would any experienced O-scope users care give a brief tutorial or summary on how you use this tool to troubleshoot and or improve your designs?

Is this Hitachi V-600 any good?

Regards,
Danny

[jjman]

1st step is to learn about how signal/voltage waves look. Sine, shape, phase, frequency clipping/distortion oscillation/ringing and strength/voltage need to be recognizable. Then move on to safety including ac vs dc including ac riding on dc. Then learn what "triggering" is on the scope. Then you can start to learn what the scope does and how you can employ it.

[Decko]

JJman,

Can you direct me to a good tutorial or booklet?

I have Merlins book but it is not a primer for Oscopes.

Regards,
Danny

[Phil_S]

Search youtube for videos. I wish I had bookmarked the one I liked. I saw quite a few windbags and similar individuals who were full of themselves or full of something else. I found a few that got right down to brass tacks and made quick work of the tutorial. You'll know the windbags right away and I suggest you move on to the next one. It is easy if you find a decent demo.

This isn't the one I like, but it's a start.
http://www.youtube.com/watch?v=hUIgAu3QQWQ&feature=fvst

This may have been it:
http://www.youtube.com/watch?v=zQDuZ3a6 ... re=related

[overtone]

try:
How to Use Oscilloscopes and Other Test Equipment by R.A. Penfold

Covers the basics, cheap and concise. It will get you started. I don't know of any book that covers our specific interest. Maybe a niche for someone.

Best, tony

[jjman]

I couldn't find any real tutorials online but I was looking before youtube.

A signal generator is needed. I built a cheap kit that works fine.

[img:240:240]http://www.parts-express.com/images/ite ... -118_s.jpg[/img]

http://www.parts-express.com/pe/showdet ... er=320-118

Important to note that it puts dc on the output so you should put a cap before it's output. That was pretty shocking to see but easy to fix. I think I used 0.1u small poly one. I also added an led indicator since I kept leaving it on. I don't see any crossover distortion from it that someone comments on in the listing. I'm sure this unit is not "proper" for precision applications but guitar amps are far from that.

[Prairie Dawg]

Hi Tagers,

Just picked up an O-scope.

Hitachi V-660

I wanted to take the guess work out of troubleshooting my amp builds.

I do not know the first thing about using O-scopes. I plan to scour the web for the users manual.

Would any experienced O-scope users care give a brief tutorial or summary on how you use this tool to troubleshoot and or improve your designs?

Is this Hitachi V-600 any good?

Regards,
Danny

I'll too be interested in seeing how this thread develops and yes, there are many windbags out there.

I've also picked up a Hitachi 100mhz dual trace scope and a good signal generator, seems to work ok and I have a dummy load.

Here's what I'd like someone to tell me. I've got a hand wired 5C1 clone I built that will make a great learning tool.

Where do I hook up to read what? What am I looking at? What is its significance?

When doing this what precautions should I take to avoid blowing up my scope?

I do not intend to use this for anything but guitar amps that are distorting. No radio, no tv, no medical equipment. Ever. I know when I'm out of my depth.

Thanks

[Jim Mason]

Go to www.tek.com and download "The xyzs of oscilloscopes".
Its located under support/learning center. I think you have to register to download it, but it I used to give a copy of it to all my new hires.

Jim

[surfsup]

Prairie Dawg and all...where to hook up...

the input tip for input pp voltage
after the coupling cap to read plate
before the cathode RC to read cathode
after PI caps to read PI signal to MV or PA
speaker tip jack to read speaker

A dual trace with two probes is nice, can compare on same screen unless your scope will store a screen shot for comparison. However, having them both live is better.

Mine will do dual trace and store stuff on the scope or on the PC which is nice. I suggest you learn how to "see" even and odd order distortion. that helps too.

[Decko]

Hi Jim, Phil, JJ, and all who responded,

My plan is is to study this piece of equipment first. I down loaded the "xyz's of oscopes" from TEK and viewed a couple vids off YouTube.

Once I have a better understanding I will comeback for questions.

In the meantime, is there a piece of software that can turn my laptop into a signal generator? I have the mbox for recording. I was thinking that I can 1/4 inch out from the box to my amp head.

Regards,
Danny

[Reeltarded]

http://www.sillanumsoft.org/

Will this help?

[rdjones]

Where do I hook up to read what? What am I looking at? What is its significance?

When doing this what precautions should I take to avoid blowing up my scope?

Connect the scope ground lead to chassis first.
It's easier to have a separate banana-to-alligator ground connection rather than the ground clip that hangs from the probe body.

The Tek xyz (pun?) book is good scope primer.

Use a hook clip on the end of your probe tip and hook it to you test point before powering up to avoid slipping and shorting a (for example) high voltage plate socket terminal.
Use the probe on 10x to minimize potential risk to the scope.

rd

[alvarezh]

In the meantime, is there a piece of software that can turn my laptop into a signal generator?

Tons of them here:

http://www.youtube.com/watch?v=R7D1f6U6TpU

Cheers

[surfsup]

Just put a tone on your MP3 player, or computer I guess, with a 1/4" converter jack into the amp.

http://www.mediacollege.com/audio/tone/download/

You don't need a signal generator if you have a PC. What you do need though is a dummy load! If you run the tone, make sure to turn your amp all the way down. They are loud and way more voltage than a guitar pickup. You will need to turn your WMP device or MP3 down to a low level. I do this on my PC and from memory I need to be at -15dB to get about 100mV input into the amp.

[Kazooman]

The freeware version of this signal generator works well.

http://www.dr-jordan-design.de/signalgen.htm

The sine and triangle waves are very good, but the square wave is not quite as nice (a common trait for PC signal generaotrs).

It is very easy to build a simple signal generator yourself.
CHeck out geofex.com. CLick on "FX Skills" at the top of the "Regular Features" menu at the left and select "A quick and dirty audio test oscillator".