Which oscilloscope?

[beasleybodyshop]

Been looking at a few oscilloscopes in the web recently. I see several USB scopes as well as discrete, "old fashioned" ones.

What are the pros and cons of the PC based scope? I kind of like the idea of hooking one up to my PC and (theoretically) having more control, but the standard ones are more portable (I only have a desktop)

Thoughts?[/list]

[DonMoose]

I'd be nervous about hanging something off a USB port that then sees plate voltages. The handheld digital scopes are clumsy, IMO.

Look for at least 2 channels with sample rates of at least 1MHz/channel if all you're looking at is baseband audio. If you're looking at any microcontroller or radio stuff, you're going to want higher sample rates.

[roberto]

I've bought a netbook and a basic two channel 20MHz scope for tube amp stuff. Including a signal generator, you can stay below 500€.

Find a scope with a USB connection, so you can download the data.

[beasleybodyshop]

As far as a signal generator is concerned, could I use a PC program and run a connection from my headphone jack to the front end?

[martin manning]

As far as a signal generator is concerned, could I use a PC program and run a connection from my headphone jack to the front end?

More convenient is to run a phone app. I have one called SignalSuite that is pretty good, does sine, rectangular, triangle, sawtooth, and sweeps; two channels too.

[xtian]

As far as a signal generator is concerned, could I use a PC program and run a connection from my headphone jack to the front end?

More convenient is to run a phone app. I have one called SignalSuite that is pretty good, does sine, rectangular, triangle, sawtooth, and sweeps; two channels too.

As I noticed after I got an analog scope, the iPhone cannot generate a true square wave. Does a decent sine, though.

Also, and don't ask me why I know, remember to protect your phone from HV with a 600+ volt capacitor!

[roberto]

It doesn't give square waves neither at low frequencies?

[Structo]

I was lucky enough to be gifted a Tektronix 465B scope.

100 MHz Dual Trace Oscilloscope discontinued in 2000.

Probably way better than necessary for a guitar amp.

Thanks John!

[xtian]

Here are o-scope traces from my iPhone 5, using the Oscillator app, cranked to max voltage, at 1kHz. The sine wave is at 2v p-p. As you can see, the square and triangle waves are very approximate. The wave shapes were similar at all freq.

[Structo]

Man that is a weird wave form.

I was always hesitant about the software oscilloscope's.

Like a previous poster said, I don't like the idea of putting power tube plate voltage to an interface of my PC.

I was lucky to get the scope I did, but there are adequate scopes brand new (although Chinese) for around $300-350 brand new.

But whatever, they are a great tool for troubleshooting.

Merry Christmas everyone!

[JazzGuitarGimp]

Here are o-scope traces from my iPhone 5, using the Oscillator app, cranked to max voltage, at 1kHz. The sine wave is at 2v p-p. As you can see, the square and triangle waves are very approximate. The wave shapes were similar at all freq.

Wow, that's a whole bunch of ringing on the square- and sawtooth-waveforms! Is that a FREE app (I hope)?

[martin manning]

I've not found any phone apps that are good at square or sawtooth, you need a real function generator for that. But, having a sine wave generator that can do sweeps in your pocket is pretty nice. There isn't much risk connecting the phone output directly to a tube amp input, but I would not connect it elsewhere, even with a DC blocking cap.

[xtian]

Wow, that's a whole bunch of ringing on the square- and sawtooth-waveforms! Is that a FREE app (I hope)?

Yes, free app. But I think it's the DAC in the phone that's not able to do square, not the app. Doesn't that seem likely?

[gktamps]

My Tektronix 485 has bitten the dust. I was just starting to learn how to use it, starting with checking capacitor foil orientation, then putting square and sine waves through it to learn the adjustments, with the goal of learning how to take measurements throughout the signal chain of my amps.

It seems to me that oscilloscope technology must be evolving fairly rapidly. Would anyone like to share their opinions about what brand/type/model I should be considering? I'm good with spending several hundred bucks if that makes sense.

Thanks!

Greg

[xtian]

If I was shopping for new, I'd go for a digital scope:

http://www.amazon.com/PDS5022T-Portable ... B007T6XNCA