User's Manual

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 lighting.
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.