TECHNISONIC INDUSTRIES LIMITED
www.til.ca
TAF-550 Installation & Operating Instructions
TiL 96RE187 Rev D
1-4
1.3 MODES
OF
OPERATION
The FM/AM selector switch located on the front panel of the TAF-550 is used to select operation
of either the TFM-138B FM Transceiver or the 91-DE AM Transceiver. The receive audio of the
selected transceiver will be routed over the headphone jack. Similarity the microphone connected
to the TAF-550 front panel will route transmit audio to the selected transceiver. Speaker Rx audio
for each transceiver can be manually turned on or off by the switch located under each speaker.
1.3.1 Transmit/Receive
Each transceiver may be operated in either of two modes; transmit or receive, as selected by the
Press-to-Talk (PTT) switch on the microphone.
(1)
TRANSMIT MODE
- When the PTT switch on the microphone is pressed, the transceiver
operates in the transmit mode. The PTT signal line is grounded by the microphone PTT
switch via the microphone lead and the MIC/PTT connector to the transceiver.
On the TFM-138B either a “TX” or “TT” will be shown after the frequency on the
alphanumeric LED display. A “TT” rather than a “TX” indicates that either a transmit
CTCSS tone or DPL code has been programmed.
For the 91-DE the Tx ON amber LED will go ON, indicating that the transmitter is
activated. Transmission will occur on the channel frequency displayed on the Liquid
Crystal Display (LCD). Frequency is determined by keypad entry of the operating
frequency or by recalling a stored channel.
(2)
RECEIVE MODE
- When the PTT switch on the microphone is released, the transceiver
operates in the receive mode.
On the TFM-138B either a “RX” or “RT” will be shown after the frequency on the
alphanumeric LED display. A “RT” as opposed to an “RX” means that a receive CTCSS
tone or DPL code has been programmed.
In the receive mode on the 91-DE the Tx ON amber LED will go OFF, indicating that the
transmitter is inhibited. Reception of the frequency displayed on the LCD will occur.
For the 91-DE the setting of the SQUELCH CONTROL determines the squelch threshold
level. When the SQUELCH CONTROL is rotated in the counter-clockwise direction, the
SQUELCH INDICATOR green LED will go ON, indicating that the squelch circuit is
connecting the demodulated audio to the VOLUME CONTROL. The setting of the
VOLUME CONTROL determines the audio level produced from the internal speaker.
When the VOLUME CONTROL is adjusted in the clockwise direction, the audio level will
increase.
The TFM-138B main and guard receiver squelch settings are located on the bottom panel
of the TFM-138B chassis. The TFM-138B squelch is factory set to 0.5uV.
1.3.2
AC and DC Operation
The unit can be operated by external 120 VAC, external 28 VDC, or external 12 VDC power.
1.
AC OPERATION
- An AC power cord P/N 927002-1 is supplied in the rear access cover
of the portable case assembly. During AC operation, the operator can elect to trickle
charge external batteries (24 V only) when connected to the DC connector configured for
24 Volts.
2.
DC OPERATION
- The unit can be operated from an external 24V DC supply within the
range of 21.6 VDC to 30 VDC. A DC connector is mounted on the rear of the Modular
Chassis which mates with DC Power Cable P/N 963212-1 (Not Supplied) to facilitate
external DC operation. DC Power Cable P/N 963213-1 will allow operation with a 12V DC
external input supply and is included with The TAF-550 System.
