Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!gatech!bloom-beacon!oberon!neuro.usc.edu!annala
From: annala@neuro.usc.edu (A J Annala)
Newsgroups: sci.electronics
Subject: HELP:  FM Recording of 300-3KHz channels on 50 KHz tape deck
Message-ID: <15020@oberon.USC.EDU>
Date: 30 Jan 89 08:00:19 GMT
Sender: news@oberon.USC.EDU
Reply-To: annala@neuro.usc.edu (A J Annala)
Organization: University of Southern California, Los Angeles, CA
Lines: 27

I am a neurobiologist with a theoretical exercise in electronic design
that might prove to be very useful in reducing the cost of recording
equipment used by the entire neuroscience community.  

I have a HP3964A four channel reel to reel tape deck.  Two of the four 
channels are claimed to have a passband of 70-64,000 Hz (plus or minus
3 db).  The problem is that I am recording data with from an electrode,
amplifier, filter combination with a passband of 300-3,000 Hz.  I want
to be able to multiplex the recording of as many of these 300-3,000 Hz
channels onto the 70-64,000 channel as possible.  In the old days (with
much smaller electrode frequency ranges [0-300 Hz we were able to encode 
three data channels on three separate FM carriers) as the input to one
channel on a music quality stereo tape deck.  I suspect the same kind of
frequency division multiplexing (if that is the correct term) should be
possible here.  But I haven't a clue how to go about the parameters,
design decisions, or implementation details for carrying out such an
encoding scheme.  I would appreciate any posted comments, email to me
(annala%neuro.usc.edu@oberon.usc.edu), and/or US mail of details for
how to build an encoder for my tape deck.

Thanks, AJ Annala

Psychology Department
SGM-1011B / Mail Code 1061
Univ. of Southern California
University Park
Los Angeles, CA 90089-1061