How big is MP3 file of 3 hours of audio at decent fidelity?

[Muse]

I do a DJ show at a college radio station and currently make cassette recordings of my shows, generally 2.5 to 3 hours of stereo audio. At the moment I have somewheres around 500 such cassettes. These have come to be a problem, and I'm building racks to organize my tapes.

I'm wondering about MP3 audio, about which I don't know too much. At the station we are looking forward to implementing a computer system that will, among other things, record a DJ's show so that they can take it home with them as an MP3 file. I suppose there's no reason why I can't presently record my show at home with my computer, soundcard, and receiver as an MP3 on one of my hard disks. See link to Rigzilla below for the specifications on my system.

How big would these MP3s be? Is it impractical to make an MP3 of each show (I do one a week)? Obviously, HD space is getting cheaper, but it still may be impractical in the foreseeable future. What are the numbers?

Currently, I'm making my cassettes on a dubbing deck that has a timer switch so that when my digital timer goes on, it starts recording and my receiver is set to my station. I hear that you can't find these dubbing decks in the stores any more (Berkeley, CA). I wonder if they are available still in Europe. Anyways, thanks for the input!

 

[WillyF1uhm1]

In general, I take as a rule, that 1 minute audio equals 1 MB in MP3. A 3 hour recording would then be approx. 180 MB. This could be less of course. So you could store 3 (maybe 4, if the files are smaller) recordings of your shows on 1 CD-ROM.

edit On a 40 GB harddrive that would be >200 recordings. with 1 show a week, that would be enough for 4 years.

 

[agentK]

I was about to say the same thing. for a 128 bitrate MP3, approx. 1 minute equalls 1 meg.
Increasing the bitrate level (160, 192, etc) increases its file size but has a better audio quality than the lower ones.
So, taking that 3 hours would result in a 180mb file size, thats a little more than a quarter size of a 700mb recordable cd.

 

[Muse]

Well, given that FM stereo isn't the greatest fidelity to begin with, what bitrate would roughly correspond to the quality that is attainable from a receiver?

Another equally good question: What bitrate would roughly correspond to what I would wind up with from a normal bias cassette (I buy the cheap ones for less than a dollar)? Thanks!

Also, are we talking stereo here with 1 MB per minute for 128 bitrate?

Also, does anyone know how I could get my computer to start recording at a specific time? Thanks again!