Date   : Tue, 13 Feb 1996 17:27:16 +0000 (GMT)
From   : amh15@... (Alan Hart)
Subject: Reading tapes

Just a suggestion for reading tapes...

Might it perhaps be worth doing some serious digital filtering of the data? 
You could do an FFT on the whole sample, filter out everything above (say) 
3kHz and below (say) 600Hz, then FFT it back. That should work, shouldn't 
it? I know you always get complications, with your data ending up being 
complex [do you just take the real part?] but it should remove a hell of a 
lot of noise. In fact, I was wondering whether some notch filtering would 
be possible - but presumably if you permit only 2400 and 1200Hz, you won't 
be able to register transitions between these frequencies. Or is that 
wrong?

Any ideas? Anyone remember their digital signal processing lectures better
than me?

Alan

Alan Hart - Cambridge University, UK - http://hydra.phy.cam.ac.uk/alan/