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From: apple!mojave!john@decwrl.dec.com (John Higdon)
Newsgroups: comp.dcom.telecom
Subject: Re: Long Distance Carrier Sound Comparisons
Message-ID: <telecom-v09i0221m04@vector.dallas.tx.us>
Date: 2 Jul 89 08:41:05 GMT
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In article <telecom-v09i0220m07@vector.dallas.tx.us>, wa3wbu!gt5000!gene@
wb3ffv.ampr.org (Gene R. Trindell) writes:
> Naive question time:  How do you tell if a line is digital or analog ?

Easy. Analog repeaters generate noise known as "hiss". After a couple
of hundred miles or so, their presence is quite noticable. Complete
absence of noise on the call, therefore, would be a strong indication
that on a 1000 mile call, the bulk of the mileage is being covered by
digital transmission. No, there are no "noise free" analog circuits in
long distance telephony.