DTC Communications T2765KF User Manual

Key Fob

Covert Wireless Audio Transmitter/Recorder
Model T-2765-KF

The most important thing we build is trust

how to contact COBHAM

For operator and troubleshooting
information, customers are encouraged
to refer to the details in this manual. For
additional clarification or instruction, or to
order parts, contact COBHAM.

Customer Service is available Monday
through Friday between the hours of 9:00
AM and 5:00 PM EST at:

Tel: [phone]

Fax: [phone]

Website: www.cobham.com/surveillance

Email: [e-mail]

DTC Communications, Inc.

dba Cobham Tactical Communications &
Surveillance

486 Amherst Street

Nashua, New Hampshire 03063

copyright notice

Copyright © 2010 - 2011

COBHAM All rights reserved. No part of this
document may be reproduced, transmitted,
transcribed, stored in a retrieval system or
translated into any language or computer
language, in any form or by any means,
including but not limited to electronic,
magnetic, mechanical, optical, chemical,
manual or otherwise, without the prior
written permission of COBHAM.

disclaimer

The information in the document is subject
to change without notice. COBHAM
makes no representations or warranties
with respect to the contents hereof, and
specifically disclaims any implied warranties
of merchantability or fitness for a particular
purpose. COBHAM reserves the right to
revise this publication and to make changes
from time to time in the content hereof
without obligation of COBHAM to notify
any person of such revision or changes.

2

PN OP1920583 REV. C

manual conventions

NOTE: Describes special issues you should be aware of
while using a particular function.

WARNING: Calls out situations in which
equipment could be damaged or a process could be
incorrectly implemented, but in which operator safety is
not a factor.

TIP: Describes application hints.

TABLE OF CONTENTS

Introduction ....................................................................................................................4-5

Accessories .................................................................................................................. 4

Quick Start................................................................................................................4-5

Operation .................................................................................................................6-10

Programming ..............................................................................................................11-19

Watermarking ..............................................................................................................20-21

Specifications ......................................................................................................................22

Contact Us ......................................................................................................................23

3

INTRODUCTION

Accessories

• 1 T-2765-KF Transmitter

• 2 AAA Lithium 1.5V batteries (non­rechargeable)

• 1 Data sheet

• 1 Operator’s Manual

• 1 Screwdriver

• 1 Programming/Watermark Software

• 1 USB Cable

NOTE: The unit does NOT power
up automatically when the
battery is inserted.

Microphone

Introduction

The T-2765-KF is a disguised surveillance device hiding an integrated microphone, synthesized
analog FM (narrow or wideband) VHF radio transmitter and high-capacity (1GB) digital audio
recorder with real-time clock and watermarking. It picks up local audio and transmits and/
or records it. The powerful 100mW transmitter can be received by compatible receivers. It
is powered by a single, commonly available, AAA Lithium 1.5V battery, and can operate for 3
hours, when both transmitting and recording, or 14 hrs when recording only. Local control is by
3 buttons on the unit. When a button is pressed, a vibrator motor provides positive momentary
feedback of the operating mode to the user. Unit configuration, and recorded audio data
download, is performed over a USB connection via supplied software

The T-2765-KF transmitter incorporates its own internal Tibbets microphone, that can be
configured for AGC (Automatic Gain Control) mode for maximum audio dynamic range, or
fixed gain.

The frequency of the T-2765-KF is user-programmable (recommended within ±1MHz of
factory setting). It is designed for personal protection and evidence gathering missions.

The Keyfob disguise is designed to look like an authentic factory-supplied unit to allow its overt
presence without attracting attention.

This manual describes the operation of the Keyfob T-2765-KF.

NOTE: There are no visual status indicators (eg: LEDs) on the unit.

Mini-Keychain Screwdriver is included in kit for changing

the battery. Turn either barrel-end counter-clockwise to

reveal the required Phillips head.

Phillips Slotted

4

The following Quick Start procedure assumes the T-2765-KF has already been configured
via USB as desired. Factory-set transmit frequency and/or other parameter settings can be
modified as described in the Programming section, starting on page 11.

Install the battery by removing the End-Cap using the screwdriver provided, and inserting
the battery, with anode (battery button) head first (unit is protected against accidental
insertion the wrong way round). Re-attach the End-Cap. Note that the unit does

not

power up

automatically.

A Vibrator Motor gives momentary feedback of operating status when buttons are depressed.
Functionality is controlled by the buttons to be in one of five modes:

QUICK START

USB Connector - Battery

Mode Initiating Button(s) Tactile Feedback

RECORD: Unlock 1 pulse

TRANSMIT: Lock 2 pulses

TRANSMIT & RECORD Lock then/or Unlock* 3 pulses

PANIC Panic 4 pulses

(SWITCHING) OFF: Lock AND Unlock Vibration switches on
then slowly dies away.

Whenever one of the above modes is toggled off, the resulting mode is whatever is indicated
by the Vibration feedback.

*If RECORD is activated when TRANSMIT is already active, or vice versa, the unit enters
TRANSMIT & RECORD state.

The T-2765-KF is designed to operate in the 150 - 174 MHz frequency band.

Battery
Compartment
End Cap

Transmit ON/

OFF Button

Record ON/OFF

Button

Panic ON/OFF

Button

5

OPERATION

Tibbets
Microphone

Unit Configuration Prior To Deployment

The unit is configured prior to deployment with supplied software via the USB connector. This
allows the user to:

• Set the transmit frequency. It is recommended to stay within +/- 1 MHz of the factory
setting (or significant transmit range reduction may result).

• Select AGC (Automatic Gain Control) or Fixed Gain audio mode.

• Download, and delete, recorded audio files.

• The User is also provided the Serial Number of the device when the unit is connected.

For details of the configuration operation, see Programming, starting on page 11.

Local Control

Control in the field is via the three buttons. They allow simple switching of the Transmit and
Record functions, plus a Panic mode that overlays an alarm tone on the transmitted audio (not
present on the audio recording) to silently alert monitoring teams to an emergency situation.
The Panic button incorporates 3 Braille dots for location out of the user’s range of vision (e.g. in
a pocket). Feedback indicating operating mode is provided by vibration.

6

Button Operation

• To prevent accidental activation, all buttons require at least a 1-second depression.
The Panic-OFF function requires a 3-second press.

• The TRANSMIT, RECORD and PANIC buttons toggle their respective functions ON and
OFF.

• If the unit is OFF, it automatically powers ON when the any of the three buttons are
pressed.

• PANIC (Alarm icon) - This enables/disables a 1kHz pulsed audio tone on the Radio
transmission, and facilitates silent signaling to those monitoring the radio transmission.

• RECORD (Unlock icon) - This activates/deactivates the integrated Audio recorder

• TRANSMIT (Lock icon) - This activates/deactivates the radio transmitter

• The unit is switched OFF by depressing the TRANSMIT and RECORD buttons
simultaneously. You may also turn-OFF each individual function by pressing the
appropriate button.

• Status Indication - The unit has no visible indicators to prevent compromise of the
unit’s covert nature during operations. It contains a small Vibrating Motor that provides
momentary feedback when buttons are depressed to confirm the operating mode
(TRANSMIT ONLY, RECORD ONLY, TRANSMIT & RECORD), or OFF. See page 5.

NOTE: If the unit is transmitting, pressing a button will cause the transmission to
cease during the vibration feedback response period. Transmission is immediately
restored thereafter. Recording is not similarly affected.

OPERATION

Transmit ON/

OFF Button

Record ON/OFF

Button

Panic ON/OFF

Button

7

OPERATION

NOTE: Always make sure you have

fresh batteries installed.

TRANSMITTING

The FM transmitter operates in the following mode:

• Analog Narrow - 2.5kHz FM deviation

NOTE: The unit does NOT power
up automatically when the battery is
inserted.

NOTE: Behavior when SD card fills up
while recording: If, while recording,
the device runs out of SD storage
space, the device operation will go
to a non-recording state. This will
be the OFF state if RECORD only was
set or TRANSMIT if the TRANSMIT &
RECORD mode was set. No indication
is given during these transitions (to
avoid compromising the user by
unexpected vibration).

NOTE: Behavior when SD card is
already full: If, when trying to activate
the RECORD mode of the Key Fob,
you do not get the expected vibration
feedback from the device (1 vibration
for RECORD only, or 3 vibrations for
TRANSMIT & RECORD) then the SD
card may be full. You would need to
download and/or delete some or all
existing files to make space.

8

Note that transmitted audio is analog, and is not
scrambled or encrypted.

WARNING: Always make sure the unit is properly turned-OFF before removing the
battery cover. If, while the unit is recording, the end cap is removed, thereby breaking
the battery connection, the audio recording may be irretrievably corrupted. Ensure the
unit is switched OFF using the Transmit and Record buttons (see page 7) with vibrator
feedback confirmation prior to end cap removal.

• Press the Lock (TRANSMIT) button to turn the unit ON and commence transmission.

• Turn ON a radio receiver tuned to the same frequency. Verify reception by hearing the
transmitted live audio.

RECORDING

The unit records uncompressed audio in .wav files that, when downloaded, can be replayed on
Windows Media Player, or other compatible software. The recorded audio is band-limited to
the range 300 – 3000 Hz. Dynamic range is not preserved in AGC mode. In Fixed Gain mode,
the dynamic range is limited to approx 40 dB.

The unit can hold up to 20 hours of recorded audio. A new audio file is created for each
recording session (i.e. whenever Recording is toggled on then off). If the memory becomes
full during a recording, Recording will stop. It is the User’s responsibility to ensure adequate
memory (28.8 MB/hr) is available at the start of the mission.

NOTE: File size is limited to 60 minutes for technical reasons. For continuous
recordings exceeding one hour, a new, seamless file is automatically created every hour.