Parts List

2-2 VHF Enhanced Transmitter Instruction Manual VT-3 132 - 174 MHz
• MODE 2: Jumper J6 in, jumper J7 in the 'y' position, jumper J18 in the 'x' position
- the audio processor is switc hed by a PTT signal
- the synthesizer module is enabled all of the time
- standby current: Typically 65 mA
- start-up time: Typically 25 ms
• MODE 3: Jumper J6 in, jumper J7 in the 'x' position, jumper J18 in the 'y' position
- the audio processor is enabled all of the time
- the synthesizer module is switched by a PTT signal
- standby current: Synthesized - not used in this mode
- start-up time: Synthesized - not used in this mode
• MODE 4: Jumper J6 in, jumper J7 in the 'x' posit ion, jumper J18 in the 'x' position
- the audio processor is enabled all of the time
- the synthesizer or crystal module is enabled all of the time
- standby current: Typically 90 mA
- start-up time: Typically 10 ms
The front panel depicted in Section 3.1 bears a DPDT toggle switch (mounted on the Front Panel
Board; see the Transmitter Main Board Manual) which controls the operation of the VT-3 132 -
174 MHz Transmitter. When in the 'OFF' position, the transmitter is turned off; however, the + 13.8
Vdc remains on the Transmitter Main Board terminals and on the Amplifier Module. When in the
'KEYED' position, +9.5 Vdc is supplied to the transmitter circuitry and the transmitter is
continously transmitting. When this switch is in the 'NORM' position, +9.5 Vdc is supplied to the
transmitter circuitry although the transmitter remains quiescent until keyed from one of several
Push-To-Talk (hereafter PTT) inputs. The red indicator LED is illuminated during transmit.
Microphone, RF output and optional reference input are mounted on the front panel; power and
other signal connections are provided by a type 'F' connector at the rear of Transmitter Main Board.
Details on their function can be found in the Transmitter Main Board Manual.