From: utzoo!henry
Newsgroups: net.dcom,net.micro,net.unix-wizards
Title: noise on triple modems 
Article-I.D.: utzoo.2851
Posted: Thu Mar  3 16:55:36 1983
Received: Thu Mar  3 16:55:36 1983

We have an annoying noise problem on our autodialer.  When we dial one
particular site (actually, it's a Gandalf PACX with several sites on it)
at 1200 baud, we get noise bursts on the line often enough to make the
connection unuseable.  The noise is strictly one-way:  it is received
here but not at the other end.  When the line is idle, it comes through
as two characters: "}i".  The bursts come at more-or-less random times,
typically every few seconds.  Does anybody know what might be causing it?

Some possibly-relevant details:  It happens only at 1200 baud.  Our modem
is a Racal-Vadic 3451PA.  This is the only 212-only local site we talk
to (all the others are triple modems), but we also call long distance
to decvax (which is 212-only) and the problem definitely does not occur
on those calls.  Our modem was checked out by the local rep's maintenance
boys just recently;  clean bill of health.  The noise starts before we
talk our way through the PACX, and is independent of which machine we
ask to talk to and which of the PACX's 1200-baud phone numbers we call.

Anybody have any ideas on this?  It's a damn nuisance.