Redpitaya Forum

Hi
I'm new to the product and can't quite work out what it does from the blurb. I want to (initially) use it to test and realign a vintage valve radio (lots of high voltages!). So I need it to generate sine waves of reasonably accurate frequency up 30MHz and simultaneously function as an oscilloscope.
1. Can it do this?
2. How accurate is the frequency and amplitude measurement?
3. What does the 'calibrated' product do that the basis one doesn't (apart from cost more!)
I can knock up attenuators and dc isolation components as necessary so the low voltage input and output compared with a 'real' oscilloscope shouldn't be a problem (though some available extra bits would be nice).

Any advice very much appreciated.

1. Yes, if I understand your need correctly. Connect to the RP via its web interface and choose the oscilloscope app. It acts as a dual channel scope up to ~60MHz and as a dual channel function generator (also up to ~60Hz, sine/square/arbitrary).

2. Depends what you mean. How accurate do you need? Amplitude generation/measurement is probably accurate to less than 1%. If you want to *measure* frequency, you have to use the spectrum analyzer app which means you can't use the function generator (I think - haven't used it for a while). I'm assuming you want to generate a signal of known frequency and look at the response of the various stages of the radio. The oscilloscope app will be fine for this.

3. Calibrated just means that the voltages generated and measured have been compared against a known reference standard. Personally, it's unnecessary unless you need very accurate voltages. I would think that an uncalibrated RP is as accurate as the original measurement equipment used when the radio was made.

If you have to dive into the realms of measuring modulation depth etc, things may get a bit more complicated (and frustrating).

BTW, don't expect the oscilloscope app to give you the flexibility, speed and ease-of-use as a dedicated 'scope (such as my trusty 1974 Tektronix 465!)

Hope this gives you some idea.