Simple Fax Interceptor

Overview

This hack is for a simple and portable facsimile interceptor.  It is based around a slightly modified Panasonic PC/FAX Store 40, Model KX-FB40.  This device is a stand-alone fax receiver that is meant to take the place of a regular, full-size fax machine.  The stock Panasonic PC/FAX Store 40 can store up to around 40 pages of standard text faxes.  The Model KX-FB80 will double that to around 80 pages.  The stored faxes are then "downloaded" via a computer with a fax modem and fax software which has a Manual Receive Now option, such as WinFax or Microsoft Exchange.

A good use for this device is to add an external 12 volt rechargable battery and some aligator clips for the phone line connector, then hide it at the bottom of a telco Network Access Interface (NAI) or terminal box at your intended target's phone line location.  Of course, you'll need to somehow physically disconnect the phone line going to your target's fax machine, as you don't want their fax machine to pick-up!  If you really want to be sneaky, set up remote call forwarding on the target's fax line and forward their fax calls to some phone line out in the boonies.  Anyone calling the target's fax phone number will automatically be forwarded to your new interceptor box.  Collect your faxes, disconnect the box, clean up your mess, and disable call forwarding (or reconnect the wires to the binding posts).  Easy as pie.

A couple of little bugs with this operation, though.  You'll need to manually set the Panasonic PC/FAX Store 40 to answer on the same number of rings as the target's fax machine to avoid causing any suspicion.  Also, if the target's fax machine has one of those customized "message received" messsages, well, you're screwed.  Remember though, people are stupid.  Especially if they are $2600 Magazine subscribers.

The complete twenty page Panasonic PC/FAX Store 40 operating instruction manual will be included at the end of this article.  It explains the computer/software setup in much more detail.  It will also tell you how to adjust the number of rings before answering.  It can only be set to one, four, or five rings.

Pictures

Panasonic PC/FAX Store 40, Model KX-FB40 right out of the box.  I found it at a thrift store for $3.  Have fun finding yours at that price!

Front panel overview.

Rear panel overview.

Inside view.  I think the faxes are stored in a Toshiba TC58A040F EEPROM.

Connector view.  From left-to-right: PC, EXT TAM, LINE, and DC 12V.

LINE and DC 12V will need to be modified to make this device portable.

Bottom view of the main PC board.  Oh look, an extra solder pad for a Toshiba TC58A040F EEPROM.  I'll bet that is the only difference between the 40 page and 80 page models.

Side view of the LINE and DC 12V connections.

New solder connections.  On top, the stock DC power adapter was removed and two wires are soldered onto their old pads.  These will go to an external 12 volt rechargable battery.  Below that, is the LINE connector.  The plastic RJ-11 jack is removed and some "J.S. Popper" test clips from an old lineman's handset are added.  Regular aligator clips will also work.  Note how they are soldered sideways.  You can use the unused solder pads on the RJ-11 jack to support for the wires.  Add a zip-tie for even more support.

New case overview.  It should be quite weather resistant.  Be sure to run the aligator clips through a hole and rubber grommet in your new case.

The main PC board is attached to the lid of the new case using a little hot-melt glue and some art foam.  Try to avoid drilling any holes.  You'll want to try and keep water out.

Some L-brackets, two-part epoxy putty, and more art foam are used to secure the Panasonic LC-R121R3PU rechargable sealed lead-acid battery.  Current draw for the device is around 300 mA during standby, and it jumps to 500 mA when receiving an incoming fax.  The power and memory LEDs can be removed to reduce the overall current draw slightly.

Completed.  Hmm...  It looks a little queer, like Emmanuel Goldstein.

Ahh...  That's better.
























Panasonic PC/FAX Store 40 Manual