rees@apollo.uucp (Jim Rees) (09/17/87)
I don't buy any of the arguments I've heard on why FM never caught on for audio tape. Many people pointed out that it is used for hifi VCR audio. True, but that doesn't explain why it isn't used for audio-only recording. Many people pointed out the bandwidth requirements. I would estimate the requirement at about 4x that of traditional equipment. That means about 4x the tape speed. You can get a reasonable signal onto cassette tape travelling at 4.75 cm/sec. So an FM signal would require a speed of 19 cm/sec (that's 7.5 ips). Sounds reasonable to me. I also don't buy the argument that digital came along before FM was really practical. I think that by about 1965 it would have been possible to build an FM audio recorder for either the consumer or the pro market. Certainly FM instrumentation recorders were available at that time (but I don't know what they cost). Even today, none of the Boston area recording studios that I know of use digital recording for their main recorders (some mix down to 2-track digital). Pro equipment often runs at 30 ips, which ought to be plenty fast enough for the bandwidth requirements. On another subject, and not to beat this to death, but why aren't we all dead from the mercury in our dental fillings? I understand that it's in amalgam, but doesn't any of it leak out of the crystal structure? Not even a little bit? It's right there in your mouth where it seems like it could do the most harm. I asked my dentist about this once, and she said it was more a hazard to her than to me.