Oscillograms/Testing, and why layout matters.

[CBS240]

Yes, all you need is oscilloscope...dear.

...and a function generator or two helps.

we are just hobbyist so can't expect much from our amp as we don't have any proper equipment to test. we hardly have one multi meter some one even don't have this. honestly tells you, i even don't know how to use oscilloscope. i am intending to buy a cheap one for my self. still looking for it. may be you guys can tells, which will be cheap and easy to use.

I have a BK Precision model 2120B, 30MHz. I saved up and bought it a couple of years ago at about $400 retail, brand new. If I would have had an extra $500, I would have bought the 100MHz version. If you can obtain used equipment, that is the way to go. My function generator isn't that spectacular. I would like to get another, better one. Little short on cash these days....
It is really very hard to determine exactly how your circuit behaves without these tools. A badly behaving circuit (oscillations and such) is a bad thing even if it sounds good. These things lead to unpredictable operation which is never a good thing in SS electronics.

... And learn to make PCB's.....

I recommend Eagle from Cad soft. A lot of people criticize this program because it takes a while to get use to, but the ability to create any part you need is really nice. Once you figure out how to create/edit components, you find it is actually very easy. The air wires makes it easy to change the layout and still maintain the correct connections. Then the CAM processor will create the print-out or the Gerber files needed by the board house. Also there is a freeware version. The old days of hand drawing PCB's are long gone.

 

[pilli]

i would like to buy a osciloscope, a simple one. i am not shure which will be btr for me.

Don't know how it is where you live, but I bought a decent Philips 50MHz oscilloscpe for under 100 Euros on eBay.
And a function generator for under 50 Eur.

what is 'scope and generator"?

"scope" is a short word for "oscilloscope"

"generator" is a "function generator", see for example
http://en.wikipedia.org/wiki/Function_generator


One more suggestion for a very useful piece of equipment (at no cost!):
I was amazed at how well a normal AM radio can detect oscillation. Keep the radio close to the circuit to check, between stations (that means not well tuned on a channel). Any noise occurring when your circuit is on, is a sign of some problem.
(To stay on topic, with the radio method I cured a couple of wire routing problems; didn't suspect how much influence that has. We read it hundreds of times, but not until we see/hear/touch it...)


And for PCBs you have Eagle, as suggested, and the "toner transfer" method that give decent results.


On all these topics there are so many tutorials on the internet, that I won't even suggest a link


Mooly, thanks for the examples and advice, here and elsewhere.

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