Parts List

2-4 VHF Enhanced Transmitter Instruction Manual VT-3 132 - 174 MHz
A channel can be selecte d from a set of 15 (maximum possible) factory programmed channels by
the four channel select lines available at the rear 'F' connector on the Transmitter Main Board. A
single user selectable channel is set by switches located on the Transmitter Main Board. See the
Transmitter Main Board Manual for details.
2.3 Transmitter Assembly and Adjustment
All modules are mounted on the Transmitter Main Board which then forms a single assembly. An
enclosure is formed by an extruded aluminum shell that slides over the Transmitter Main Board as
illustrated in section 3.2). This shell also serves as a heatsink to remove heat from the Amplifier
module and for this reason, it is important that the four screws that bond the shell to the amplifier
module (Screws B in Section (3-2)) be installed before prolonged operation of the transmitter.
Moreover, the surface of the Amplifier module that contacts the shell should be clean and free of
foreign material. The enclosure is completed by the installation of front and rear plate s which are
fastened to the Transmitter Main Board (see Transmitter Main Board Manual for parts lists).
Transmitter alignment is performed on a module by module basis and detailed steps are provided in
the respective manuals. Alignment is simplified by using an SR-3 Sub rack, SM-3 System Monitor,
and RF extender cable to provide transmitter power and signal interconnection. Alternatively, +9.5
Vdc and +13.8 Vdc, as well as any required test signals, may be applied directly to the individual
modules. Refer to the corresponding manuals for details.
2.3.1 Complete Transmitter Alignment
A complete Transmitter Alignment is performed at the factory and should not be required under
normal circumstances. A large change in operating frequency, as discussed in the next section,
may require a complete realignment operation. This operation requires that all the transmitter
modules be aligned on a per module basis in the following order.
Sequence Module Manual Reference
(1) Transmitter Main Board Section 2.2 of this manual,
Transmitter Main Board Manual.
(2) Synthesizer Synthesizer Manual
(3) Amplifier Amplifier Manual
(4) Audio Processor Transmitter Main Board Manual