Random noise generator calibration

[BetaTripp]

Hi guys,

Does anybody have any ideas on how I could calibrate a noise generator? I was thinking maybe check it's frequency response and compare it to what is expected from the technical specifications. Or something in that area..?
The device is Astronics but I can't really find any documentation for it.

Thanks

 

[unclejed613]

if it's audio, you can check it with spectrum analyzer software. a white noise source should have a flat response to beyond 20khz, a pink noise generator should have a response that drops 3db/octave, and a red noise source drops 6 db/octave

if its a RF noise source you can test it with a software defined radio dongle and associated RF spectrum analyzer software.

astronics makes avionics equipment, so my first guess it's an RF source, probably covering one or more vhf and uhf bands used for aircraft communication and navigation electronics.

 

[BetaTripp]

Hi,

That's pretty good information. I was going to try and work something out using an oscilloscope as I'm a bit low on instruments and I don't really want to be spending all day doing FFTs so I'll check out this radio dongle thing. Is there a specific manufacturer that makes these?

Thanks

 

[unclejed613]

here's a good basic starter kit (after the info about it's features and construction, the first box you come to is the starter kit) for $39.95 that comes with the dongle , antenna cables, antenna mount, and antennae.
https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/
the frequency range is 500khz to 1.77Ghz with a max sample rate of 2.4Ms/s which allows you to look at a 2.4Mhz chunk of spectrum at a time. there are also programs available that overcome that limitation by continuously stepping the center frequency and merging the results in one graph.

 

[Dick Cappels]

A scope in the FFT mode or a spectrum analyzer would be the most helpful. To calibrate a noise source you need to specify the bandwidth and the rolloff expectations.

 

[unclejed613]

this seems to be an RF noise generator... a picture and model number would help...

 

[Dick Cappels]

Noise source => Filter => RMS value.