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From: jlg@lanl.ARPA
Newsgroups: net.audio
Subject: Re: CD Reflections - 44.1k?
Message-ID: <19964@lanl.ARPA>
Date: Mon, 21-Jan-85 14:29:15 EST
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Posted: Mon Jan 21 14:29:15 1985
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> Telephone voice-grade channels are 2700 Hz limited, filtering to allow
> signals only from 300 Hz to 3000 Hz.  So how do 4800 and 9600 bps
> modems work over dialup circuits?


They don't!  In order to get the higher bandwidth modems to work over the
phone you have to lease a special line from your local telephone operating
company (you pay by the mile).  If you want 9600 baud long distance, then
you'd better get a satellite channel leased.  Standard phone lines carry
a maximum standard baud rate of 2400, which explains the popularity of
1200/2400 baud modems these days for 'hackers' and other amateurs.

J. Giles