RE: Dead FM Broadcasting Technologies

[Garrett Wollman <wollman@lcs.mit.edu>]

<<On Fri, 29 Nov 2002 15:26:11 -0500, "Hakim Madjid" <HMadjid@mindspring.com> said:

> Theoretically, the change from 75 microsecond (50 in europe)
> pre-emphasis to 25 microsecond pre-emphasis when transmitting Dolby
> - FM was supposed to partly compensate for the treble boost created
> by the Dolby decoder when listening on non-Dolby equipped receivers.

OK, it's time for your moderator to make it quite clear that he's not
an EE.

Can one of you readers who are please explain what is meant by
``pre-emphasis'' and why it's measured in units of time?  (For extra
credit, can you explain why said units of time are invariably
represented with the wrong symbol?)

-GAWollman