I think you're talking about bias.

In the early days DC bias was applied - I think this included wire
recording. These days AC bias is applied at something like 100kHz. This
reduces noise (or allows increased recorded level which results in the same
thing) and reduces distortion. In both cases the bias is simply added to the
signal - not modulated by it (although I guess in the DC case it amounts to
much the same thing).

I also have wondered what sort of heads were used for wire recorders .
(Weren't flight recorders a wire recording until reasonably recently?)

Richard P

> -----Original Message-----
> From: Sean H. Breheny [mailto:shb7@CORNELL.EDU]
> Sent: Tuesday, October 05, 1999 4:00 PM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: OT: Wire audio recordings
>
>
> At 07:42 PM 10/4/99 -0700, you wrote:
> >and broke easily.  TAPE usually was either amplitude or
> frequency modulated
> >carrier of about 100 KHz.  I don't know about the wire but
> would suspect
> >they would have to do the same thing.
>
> What kind of tape are you talking about? You don't mean
> regular cassette
> tapes,do you? AFAIK, those are just the raw audio applied to
> the recording
> head (no carriers).
>
> Sean
>
> |
> | Sean Breheny
> | Amateur Radio Callsign: KA3YXM
> | Electrical Engineering Student
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