PC Based Oscilliscope for Tube Curcuits

[denny9167]

Does anyone know of a pc based oscilliscope for tesing tube curcuits? DIY would be great,but ready built would be fine.

[LinuksGuru]

I would suggest you to buy digital oscilloscope like Atten ADS1062CML, ML options means large screen/extra RAM.
Really good USB PC oscilloscope costs a considerable chunk of money anyway, and you should take into account that input ground and USB ground may be connected. How good is input protection of PC USB oscilloscope against high voltage is also a big question. High level of input noise seem to be a common problem of dirty cheap USB oscilloscopes.

PS. You can connect AAtten to PC via USB port if you wish to acquire data.

[Pano]

I've had good luck with the Picoscope. But in a similar price range the Atten does look very attractive, thanks for posting that.
Remember that many of these are limited to 8 bit resolution, is that's important to you. There is a 12 bit version of the Picoscope - for more money, of course!

If you don't need to measure past about 90Khz, I highly recommend using a good sound card with an interface. Quite a few of us here use that.

[LinuksGuru]

With 8 bit digital oscilloscope you have upper precision limit of 0.4%, thus, you can't use it to measure THD below that level.
However, digital oscilloscope isn't meant for such purpose.

[hidnplayr]

I use the PCS100 from velleman, together with their generator it's very usefull to do frequency plots etc.
But i couldnt live with it as my only scope...

[jrenkin]

Originally Posted by hidnplayr

I use the PCS100 from velleman, together with their generator it's very usefull to do frequency plots etc.
But i couldnt live with it as my only scope...

I use this one too, and it is fine for general work, but watch out for the frequency generator, it has a drop off of several dB at around 10khz and above if I recall properly.

[stajo]

PicoScope 4262 is especially made for analog circuits

[rknize]

I also have the old PCS500 from Velleman and their PCG10 signal generator. Be warned that they are parallel port devices, something you won't find on many modern PCs. They properly isolated though and work well despite their quirks. It was my only scope for a while, which is why I eventually got an old 2-channel Tek.

[trobbins]

I can recommend TrueRTA - simple spectrum analyser and chirp frequency response plot. One key issue is to have a non-distorting clipper (to save the soundcard) and to have stepped/variable gain/attenuators to position the signal level between noise floor and clipping. The other issue is to accept a certain level of known hum earth loop, unless you use a laptop.

Ciao, Tim

[tomchr]

Most of the PC scopes have very limited input stages. Some offer a 100 mV range, but most of them are 1 V or 10 V only. That really limits things when you're trying to measure ripple or noise in the 1~10 mV range. I also question their level of input protection against over-voltage. It would truly suck to zap both your computer and PC scope because you accidentally connected the input to a few hundred volts...

Get a real scope. You won't regret it. If you don't need data acquisition, search the equipment & tools forum for recommended scopes. It's a question that comes up frequently.

~Tom