dave@utcsrgv.UUCP (Dave Sherman) (10/05/83)
I have a Racal-Vadic VA212PA modem at home, which I use at 1200 baud.
Lately I've been noticing a *lot* of noise on the modem, expressed on
the terminal as bunches of }i{_}i and other friendly things. Most of
the noise, but not all, seems to be coming on the way back, i.e.,
UNIX doesn't see it, although occasionally it does get transmitted
(leading to "}i: not found" and the like).
This happens when dialled into two completely separate systems
(utcsrgv and lsuc), so it's obviously at my end.
Today I discovered that if I lift a phone off the hook while
I work, the problem goes away. I am sitting here listening to
the rushing-heavybreathing-interference sound that is 1200 baud
communication, and my terminal is happy. Now I would have thought
that the opposite would be true - that with a phone off the hook,
extra noise would get in and muck up the line. But as soon as I put
the phone back, }i~r~rmy}iq}i~r}i}i~r nonstop (I just did it, and
out of 10 full lines of this junk, the above is what UNIX saw).
Anyone have any ideas? Any suggestions, other than leaving the phone
off the hook? Before I found that solution, I used to just
dial in again, which usually cleared it up.
Dave Sherman
Toronto
--
{cornell,decvax,ihnp4,linus,utzoo,uw-beaver}!utcsrgv!lsuc!davesteve@dartvax.UUCP (10/08/83)
All your ~r's and }i's are well known here, too, but I don't think the modem
is to blame. I have a Ventel MD212 Plus, and the same noise has occurred at
times. The problem was levels on the phone line. The line was too "hot".
This might explain why taking the phone off hook helps the problem, though
if your phone has an exclusion key - a white cradle button that lifts -
listening in shouldn't effect signal levels.
The solution was to get the phone company to adjust the levels. Your best
bet, especially if you live in an area where data-knowledgeable telco
craftspeople are scarce, is to find a good one and make sure she/he always
looks after your line. Be persistent.
steve campbell
{decvax,linus}!dartvax!steve