1-1
SECTION 1
GENERAL DESCRIPTION
1.1
INTRODUCTION
This publication provides operating and installation information on the TFM-138 (with version
F10-B software), Transceiver manufactured by Technisonic Industries Ltd. The version F10-B
software is factory installed in TFM-138's with s/n F1540 and onwards. The unit offers 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 138-150 MHz portion of the band. If the TFM-138 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.
1.2
DESCRIPTION
The TFM-138, Transceiver is a frequency agile, fully synthesized airborne transceiver
capable of operating in the 138.000 MHz to 174.000 MHz frequency range in 2.5 kHz
increments with either 25 kHz or 12.5 kHz channel spacing. The Transceiver can operate
without restriction on any split frequency pair in the band and also incorporates a two channel
synthesized guard receiver.
The TFM-138 Transceiver provides 100 operator accessible memory positions, each of which
is capable of storing a transmit frequency, receive frequency, transmit frequency CTCSS tone,
receive frequency CTCSS tone, an alphanumeric identifier for each channel and
(in the TFM-
138 s/n 1540 and up only) wideband (25 kHz) or narrowband (12.5 kHz)
channel spacing
assignment. 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. Data
may also be entered via a PC computer with the provided software and optional PIB-100
programming interface box or via an older computer and PC Up/download cable, P/N 943165-
4.
1.3
PURPOSE OF EQUIPMENT
The TFM-138, 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 TFM-138 Transceiver. All units offer identical features
and performance except for the following differences:
TFM-138, P/N 921012-1
GREEN display and 28 Volt back lighting.
TFM-138, P/N 921012-1 (5V)
GREEN display and 5 Volt back lighting.
TFM-138, P/N 921012-2
RED display and 28 Volt back ligting.
TFM-138, P/N 921012-2 (5V)
RED display and 5 Volt back lighting.
Both P/N's 921012-1 and 921012-2 are always provided with 28 Volt back lighting unless a
specific request is made for 5 Volt AC operation.
Summary of Contents for TFM-138
Page 13: ...2 2 FIGURE 2 1 Operator s Switches and Controls TFM 138 F10 B software...
Page 24: ...3 2 FIGURE 3 1 Outline Drawing for Model TFM 138 Transceiver...
Page 26: ...3 4 Figure 3 2 Wiring Connections for TFM 138 Transceiver...
Page 30: ...3 8 FIGURE 3 4 Microphone and Sidetone Level Main and Guard Squelch Adjustment Access Holes...
Page 42: ...STEP SYSTEM PASS FAIL NOTES A 11...
