DTC Communications T99FG User Manual
H25T99FG
DTC COMMUNICATIONS, INC.
Operating Instructions for the T99FG
Version 1.0
OP1920058
T99FG Ope rating Instructi ons page 1
©1999 DTC Communications, Inc.
H25T99FG
Introduction
The T99FG is a 200mW covert transmitter board, which may be installed in host devices
such as the Motorola FLEX™ pager housing. The output power does not change over its
operational battery life, unlike other covert transmitters due to a novel step-up switching
power supply circuit. The transmission is a narrow-band FM signal, of 5 kHz deviation.
The antenna is an internal loop antenna, tuned to the specific operating frequenc y. The
audio circuitry is built around a Gennum automatic gain control (AGC) circuit, and a
high-quality Knowles microphone. The efficient switching power supply converts the
1.5 volts from the Eveready L91 Lithium battery to 4 volts for operating the transmitter.
Battery life is over two hours at a constant 200mW. The internal antenna is custom
designed, and is individually tuned during manufacturing for maximum radiation. The
pager display and controls operate normally, contributing to the covert packa ging. The
pager, however, does not receive pages.
Description
Battery
The T99FG will operate correctly ONLY with an Eveready model L91 Lithium AA
battery installed. A fresh battery will operate the unit for over two hours. The T-99-FG
will operate for less than 15 minutes with a standard alkaline battery installed.
To install the battery, hold the pager face down and proceed as follows:
1) Unlock the battery door by sliding the door latch away from the battery door.
2) Slide the battery door in the direction of the arrow (toward the outer edge).
3) Lift the battery door away from the housing to remove it.
4) Place the battery into the battery compartment, taking note of the positive (+) and
negative (-) markings on the battery and the pager housing.
5) Replace the battery door and lock by sliding the door latch toward the battery door.
NOTE: The pager will sound the power up alert and IS NOW TRANSMITTING.
The transmitter is powered up from the moment the battery is inserted into the unit.
There is no power switch.
Audio Circuit
The audio circuit is based on a Gennum automatic gain control (AGC) microcircuit and
an internal, high-sensitivity Knowles electret microphone. When the pager is placed in
the holder and worn, the microphone is located behind a small hole on the side of the
pager facing up. Excellent audio quality will be achieved if this hole is kept clear of
fingers and clothing.
T99FG Ope rating Instructi ons page 2
©1999 DTC Communications, Inc.
Loading...