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Odd Telephone Line "Signal"

Question for your guys experienced in telephone circuits...

Every 30 minutes it looks like my on-hook voltage drops from 50VDC to ZERO for a fraction of a second.

It happens so fast I can't get an accurate read on it... but the auto-ranging DVM drops from "V" to "mV"

What is this all about? ...Jim Thompson

-- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

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| 1962 | I love to cook with wine. Sometimes I even put it in the food.

Reply to
Jim Thompson
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Some one may be working at the CO.

Moving a rack or something.

I was this when I got DSL.

My Caller ID box went berserk over this for days, then it stopped.

hamilton

Reply to
hamilton

Some one may be working at the CO.

Moving a rack or something.

It was like this when I got DSL.

My Caller ID box went berserk over this for days, then it stopped.

hamilton

Reply to
hamilton

This is deadly on 30 minute intervals. I even was able to set an accurate pop-up on my calendar to make sure I watched the DVM ;-) ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |

      Remember: Once you go over the hill, you pick up speed
Reply to
Jim Thompson

This is their test desk. It probably is actually a program on their #5 ESS or whatever switch you are on, and it scans all the lines and connects the test equipment to all on-hook lines to check for anomalies like weak grounds. By analyzing this data with programs, they can detect trends, such as water getting into cables, that need immediate attention. It might not become evident from customer service requests until several weeks later.

Jon

Reply to
Jon Elson

Either the CIA, the Taliban, or Homeland Security is tapping your line.

Hope This Helps! Rich

Reply to
Rich Grise

It is the feds establishing their wire-tapping system. Since 911 this warrantless search has been increasing. And your tin hat will not help..

Reply to
Robert Baer

=A0 =A0 ...Jim Thompson

=A0 =A0| =A0 =A0mens =A0 =A0 |

=A0 | =A0 =A0 et =A0 =A0 =A0|

=A0|

=A0 =A0 =A0 |

Hi Jim

It might be those "science-fiction" analog line TDR - one dimensional radar?:

Time Domain Reflectometer (TDR):

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If somebody dig/cut/short/water-short the analog phone-line(s) the telephone company can pinpoint how far down the line it happened - and when; with an accuracy of 1/2 hour?

-

Many bigger network switches has TDR-features on TP-cable for trouble- shooting purposes.

The reason - Gbit (and 10 Gbit) requires enormous amount of DSP - why use a little DSP on TDR?

/Glenn

Reply to
Glenn

Automated loop test. If the line is inactive, it gets tested, if active then it is skipped until the next test.

--
I'm never going to grow up.
Reply to
PeterD

Hook up a scope (digital?) put it on a relatively slow trace and trigger on the drop with some pre-trigger time set.

--
Paul Hovnanian     mailto:Paul@Hovnanian.com
------------------------------------------------------------------
Fast wine, loose cars, old women.
Reply to
Paul Hovnanian P.E.

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