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From: FTD%MIT-OZ@MIT-MC.ARPA ("David D. Story")
Newsgroups: mod.telecom
Subject: Why the Vadic 3400 protocol is still alive !
Message-ID: 
Date: Sat, 26-Oct-85 03:05:00 EST
Article-I.D.: MIT-OZ.GZT.TDF.12154100049.BABYL
Posted: Sat Oct 26 03:05:00 1985
Date-Received: Mon, 28-Oct-85 01:34:22 EST
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212a being better is a lot of sh&t. Bell originally wouldn't sell
their modems and in the lease package they billed the user on data
phone rates. Bell also wouldn't give out their filter specs, sell
them, or anything else which in turn created the pocket for Vadic. If
you have noisy lines (and remember that this is recent history before
all the line conditioning and that's where Bell put the data phones)
the 3400 protocol is much better (cleaner). The 103 is coupled.  And I
don't think Vadic or Hayes Anderson (only around for 2? years for
their licens) ever had an acoustic coupler running 3400. The HA
uses their coupler for 103 only I believe. What remains to be seen is
if Vadic comes out with harmonic 2400 modems that are cleaner that
what is possibly already there. Maybe 4800 - 9600 !

Bell works on a feedback filter while Vadic works onharmonics.
The Bell filter had to let some noise in their frequency range pass
while the Vadic doesn't won't and never will. Preferable tkeep
the creepy micro people of thmainfthere shouldn't exist
a 103 or a 212a answer option strap so then stupid managers couldn't
set up that way !

Cut those straps !