[comp.dcom.telecom] Phone Dinging Around 2 AM

bruce@camb.com (Barton F. Bruce) (02/27/91)

In article <telecom11.160.4@eecs.nwu.edu>, think!barmar@bloom-beacon.
mit.edu (Barry Margolin) writes:

> On most nights, somewhere between 2 and 3 AM, my phone will
> spontaneously emit two tiny rings (it has a real bell, not a tone
> generator, and goes ding -- ding).

I get it also in Arlington MA. Not long enough to latch the 1A2's line
card for its six or so second normal memory of having seen ringing,
but enough to ding the bells. FWIW, my line cards are so HI-Z the test
board gets confused thinking there is an open line. They simply can't
'see' the cards.

I had simply assumed adding a normal phone to the line would stop
whatever automatic line testing is happening from ringing my bells
because its load would shunt whatever is goosing my KTUs. Your having
it happen now makes me wonder if my assumption is wrong.

The traditional ringer IS sensitive to the polarity of pulses!  Aside
from adjusting the bias spring, the 'proper' cure for BELL-TAP
(tinkeling as a rotary extension or other party dials or even just
goes on/off hook) is to have the phone's two wires connected properly
to TIP and RING. Early TT phones really cared, because the TT pad
wouldn't work if wired backwards. Now all TT phones have the
polarity-guard (diode bridge) built in so they are clutz proof.

You might just try reversing the two line wires. 

There may be a bias spring that can be hooked to a stiffer notch that
will help.

kabra437@pallas.athenanet.com (Ken Abrams) (02/28/91)

In article <telecom11.160.4@eecs.nwu.edu> think!barmar@bloom-beacon.
mit.edu (Barry Margolin) writes:

> On most nights, somewhere between 2 and 3 AM, my phone will
> spontaneously emit two tiny rings (it has a real bell, not a tone
> generator, and goes ding -- ding).

> Does anyone have an idea what's causing this?  Does NEw England Tel
> send out some kind of test pulse that my phone (an AT&T Trimline 230)
> is oversensitive to?

Yes, in all probability, that is exactly what is happening.  The test
is called ALIT (Automatic Line Insulation Test).  It makes two passes
at the line.  A slight adjustment on the bias spring in your phone
ringer would probably eliminate the problem.  If the problem is more
exotic, the test can be programmed to skip individual lines.


Ken Abrams          uunet!pallas!kabra437
Illinois Bell       kabra437@athenanet.com
Springfield         (voice) 217-753-7965

news@bu.edu.bu.edu (News) (03/08/91)

In article <telecom11.160.4@eecs.nwu.edu>, think!barmar@bloom-beacon.
mit.edu (Barry Margolin) writes:

> On most nights, somewhere between 2 and 3 AM, my phone will
> spontaneously emit two tiny rings (it has a real bell, not a tone
> generator, and goes ding -- ding).

(stuff deleted)

> Does anyone have an idea what's causing this?  Does NEw England Tel
> send out some kind of test pulse that my phone (an AT&T Trimline 230)
> is oversensitive to?

The telco is doing automated testing in the middle of the night.  The
phone is probably sensitive to belltap ... meaning that it would tend
to 'ding' when an extension with a rotary dial is dialed.

The ringer is responding to a test voltage on the line that has a fast
rising edge.


Tad Cook   Seattle, WA  Packet: KT7H @ N7ENT.#WWA.WA.USA.NA
Phone: 206/527-4089     MCI Mail: 3288544   Telex: 6503288544 MCI UW  
USENET:...uw-beaver!sumax!amc-gw!ssc!tad   or, tad@ssc.UUCP