Need tap into Telco line.

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Here in rapidly degenerating S.Africa where the judicial system has
become non functional, and majority controlling shareholders are
looting my inheritance by extracting all value for themselves by
way of [self appointed - legally] director's fees, I need some technology
leaverage. Obviously in a non-functioning society, you must DIY.

The looter's actions indicate that they are tapping into my phone line
which goes through their PABX.

In the telco-room I've located my pair and their pair on the
tag-blocks.

How would I best hear their speech ?
Since I've got easy regular access to the tag-blocks, and I seldom
receive calls, I could set-up occasionally for a few hours at a time.
Ie. not use a long-term set-up.

My first thought is to just temporarily connect my pair to theirs,
observing the polarity, and while leaving mine on-hook, just
tap-off my line into an amplifier, which I can hear while
I'm working.

A second refinement, would be to use capacitive coupling
to their pair.

I need to terminate my side with a high impedance, so that
the capacitive coupling can also have a high impedance.
So that it becomes insignificant when I receive or make a call.

If I remove my handset, so that only the audio amplifier
terminates my line, during 'listening in', would it work ?

And then by just connecting my handset and/or modem
could I expect to operate without significant cross-talk to
the looters line ?

Thanks for any info/feedback,

== "James bLond".

 

[default]

Here in rapidly degenerating S.Africa where the judicial system has
become non functional, and majority controlling shareholders are
looting my inheritance by extracting all value for themselves by
way of [self appointed - legally] director's fees, I need some technology
leaverage. Obviously in a non-functioning society, you must DIY.

Had you not put S.Africa - that sounds just like the U.S.

The looter's actions indicate that they are tapping into my phone line
which goes through their PABX.

In the telco-room I've located my pair and their pair on the
tag-blocks.

How would I best hear their speech ?
Since I've got easy regular access to the tag-blocks, and I seldom
receive calls, I could set-up occasionally for a few hours at a time.
Ie. not use a long-term set-up.

My first thought is to just temporarily connect my pair to theirs,
observing the polarity, and while leaving mine on-hook, just
tap-off my line into an amplifier, which I can hear while
I'm working.

A second refinement, would be to use capacitive coupling
to their pair.

I need to terminate my side with a high impedance, so that
the capacitive coupling can also have a high impedance.
So that it becomes insignificant when I receive or make a call.

If I remove my handset, so that only the audio amplifier
terminates my line, during 'listening in', would it work ?

And then by just connecting my handset and/or modem
could I expect to operate without significant cross-talk to
the looters line ?

Thanks for any info/feedback,

== "James bLond".

Don't do it, you'll be breaking the law!

Hypothetically speaking:

Assuming all telephones work the same the world over (more or less) a
capacitive coupling might be the way to go - the problem is that you
may have to use coax to keep the hum down or keep the line short - but
at least that is harder to detect. High impedance to a phone line
isn't that high - works in your favor a few thousand ohms would be
"high."

If they monitor the current - they'd pick up your extra telephone if
you wired that into the circuit - but that would have to be done prior
to the patch blocks. They'd certainly catch the clicks when you
connected, and that would give you up.

Another approach might be to add a tape recorder with a VOX (voice
operated switch) and hide that in the patch room. The advantages are
no wire directly from you to them and you'd only get caught while
checking the recorder. You don't have to be there 24/7 to listen in.
The batteries last a long time with a VOX, as does the tape.

Disadvantage is trips to check the tape and replace batteries, risk of
getting caught. You might use a wall wart to power the recorder - but
check that on your own line first to see that it doesn't introduce hum
on the phone lines. You'd still have to change tapes periodically.
Any mediocre forensics lab could lift your prints from the equipment.

Add a FM transmitter to the line - if you're reasonably close.
Downside is that someone nearby may inadvertently intercept the
signal. But it would minimize risk while checking tapes.

Finally - consider an inductive pickup. When I was in high school I
bugged my sister's conversations with boyfriends. I had this really
cheap cheesy plastic tape recorder with 3" reel to reel tapes. I
found the terminal in the basement of the house and added a coil of
wire to one side of the line (broke the connection and put the coil
-20 turns of wire ~1" diameter in series with one leg). When she got
on the phone I'd slip one of those "pickup" coils that is supposed to
go on the earpiece of one's telephone to record the conversation, into
the loop I added and recorded the conversation.

You might even be able to slip a pick up coil between the twisted pair
for enough signal - never tried it myself so I don't know if it would
work. I made a coil and that worked so I had what I wanted and didn't
experiment further.

Don't do it!

 

[Homer J Simpson]

How would I best hear their speech ?

Google (how to tap a telephone) got 15 million hits.

http://www.paladin-press.com/ would be my other search.

 

[Frithiof Andreas Jensen]

The looter's actions indicate that they are tapping into my phone line
which goes through their PABX.

So why make them aware of that? Feed them duff information at
strategic points! If I was "them" I would bug your office too and
perhaps your car to get more "coverage".

In the telco-room I've located my pair and their pair on the
tag-blocks.

So easy. Not very security conscious are they?

How would I best hear their speech ?

Buy a tape recorder designed for this application (many businesses
sell them), find an unused pair, wire that to the buggees pair in the
block (preferably on the back side of the blocks so to hide your pair
in the mess in there - but, really, would they ever check if anyone
can access the terinals?), place the tape recorder at a convenient
point on the other end of the pair. That way you only risk being seen
messing with the block once.

 

[default]

The problem with adding a coil across the line is that it will draw
current and very likely "look" like a phone is off hook.

Not suggesting a coil connected across the line, just adding a coil in
series with one leg of the line with a pick up coil to make a
transformer. The slight impedance and resistance 20 turns of wire
adds in negligible.

Come to think of it one of those audio speaker transformers might also
work and might keep the impedance low so no hum is picked up from the
line to the listening post.

 

[Tomi Holger Engdahl]

Here in rapidly degenerating S.Africa where the judicial system has
become non functional, and majority controlling shareholders are
looting my inheritance by extracting all value for themselves by
way of [self appointed - legally] director's fees, I need some technology
leaverage. Obviously in a non-functioning society, you must DIY.

The looter's actions indicate that they are tapping into my phone line
which goes through their PABX.

In the telco-room I've located my pair and their pair on the
tag-blocks.

How would I best hear their speech ?

Read those documents:
http://www.epanorama.net/documents/telecom/telerecord.html
http://www.epanorama.net/documents/telecom/teleinterface.html

Connect the output of the circuit to suitable listening amplifier
that can send the amplified sound to headphones or some other
telephone line.

Since I've got easy regular access to the tag-blocks, and I seldom
receive calls, I could set-up occasionally for a few hours at a time.
Ie. not use a long-term set-up.

My first thought is to just temporarily connect my pair to theirs,
observing the polarity, and while leaving mine on-hook, just
tap-off my line into an amplifier, which I can hear while
I'm working.

A second refinement, would be to use capacitive coupling
to their pair.

Cpacitive coupling to the pair and amplification near
the coupler is a working approach to listen to signal
on telephone line.

I need to terminate my side with a high impedance, so that
the capacitive coupling can also have a high impedance.
So that it becomes insignificant when I receive or make a call.

If I remove my handset, so that only the audio amplifier
terminates my line, during 'listening in', would it work ?

And then by just connecting my handset and/or modem
could I expect to operate without significant cross-talk to
the looters line ?

Propably not.