Instruction Manual

1-1
B page
SECTION 1
GENERAL DESCRIPTION
1.1 INTRODUCTION
This publication provides operating and installation information on the TDFM-136, Digital
Transceiver manufactured by Technisonic Industries Limited. The TDFM-136 is Project 25
(P25), Phase 1 compliant. The unit offers digital or conventional analog FM communications
over an extended frequency range with selectable channel spacing and is intended for use (in
the U.S.) only by government agencies or contractors thereto, who have obtained licensing
for operation in the 136-150 MHz portion of the band. If the TDFM-136 transceiver is used
in CANADA, operation is restricted to the following sub bands: 138-144, 148-148.99,
149.005-150.005 and 150.05-174 MHz. Furthermore the frequency agile transceiver is
restricted to airborne use must not be operated as a base station in Canada.
1.2 DESCRIPTION
The TDFM-136, Transceiver is a frequency agile, fully synthesized airborne transceiver
capable of operating in the 136.000 MHz to 174.000 MHz frequency range in 2.5 kHz
increments with either 25 kHz analog, 12.5 kHz analog channel spacing and P25, 12.5 kHz
digital modulation on a channel by channel basis. The Transceiver can operate without
restriction on any split frequency pair in the band and also incorporates a two channel
synthesized guard receiver.
The TDFM-136 Transceiver provides 150 operator accessible memory positions, each of which
is capable of storing a transmit frequency, receive frequency, transmit frequency CTCSS tone
or DPL code, receive frequency CTCSS tone or DPL code, an alphanumeric identifier for each
channel and in the TDFM-136, wideband (25 kHz analog) or narrowband (12.5 kHz analog)
channel spacing assignment. The P25 mode (12.5 kHz digital) channels include both NAC and
Talk Group capability.
Operating frequency and other related data are presented on a 48 character, two line LED
matrix display. Data entry and function control are performed via a 12 button keypad. Preset
channels may also be scrolled and scanned through keypad function activation.
1.3 PURPOSE OF EQUIPMENT
The TDFM-136, Digital VHF/FM Transceiver is designed to provide secondary airborne
communications to facilitate operations which are typically performed in a low altitude
environment. The transmitter section of this unit has a minimum of 8 watts and does not
exceed 10 watts output power, which may be reduced by a front panel switch to 1 watt, in
order to reduce interference to land based systems.
1.4 MODEL VARIATION
There are four variations of the Model TDFM-136 Transceiver. All units offer identical features
and performance except for the following differences:
TDFM-136, P/N 981087-1 GREEN display and 28 Volt back lighting.
TDFM-136, P/N 981087-1 (5V) GREEN display and 5 Volt back lighting.
TDFM-136, P/N 981087-2 RED display and 28 Volt back ligting.