Codan Radio Communications VT-3H040-S-HSO ユーザーズマニュアル
Enhanced FM Synthesizer Instruction Manual
IM10-OS3AH
29-71.4 MHz - General Information
5
General Information
Introduction
The OS(R/T)-3H Synthesizer is a compact, fully
shielded and environmentally rugged frequency
synthesis module that is the nucleus of every
MT-3 synthesized Receiver and Transmitter
radio module. The OS(R/T)-3H generates a high
stability, low distortion radio frequency signal in
one of several frequency bands. The OS(R/T)-
3H utilizes an internal temperature compensated
9.6 or 10.0 MHz reference to produce a signal
stable to ±1 ppm within the temperature range of
-40°C to +60°C. Alternately, the OS(R/T)-3H can
be disciplined by an external 9.6 MHz or 10 MHz
reference of higher stability. All synthesizer
modules are designed to be easily removed
for programming, calibration and/or repair. The
synthesizer circuitry is distributed between two
printed circuit boards (PCBs) which are isolated
yet interconnected via photo-logic optical
transceivers that effectively eliminate residual
electrical noise between digital and analog
circuitry. Further shielding of the synthesizer’s
RF fi lter circuitry is provided by an internal
shielded enclosure.
shielded and environmentally rugged frequency
synthesis module that is the nucleus of every
MT-3 synthesized Receiver and Transmitter
radio module. The OS(R/T)-3H generates a high
stability, low distortion radio frequency signal in
one of several frequency bands. The OS(R/T)-
3H utilizes an internal temperature compensated
9.6 or 10.0 MHz reference to produce a signal
stable to ±1 ppm within the temperature range of
-40°C to +60°C. Alternately, the OS(R/T)-3H can
be disciplined by an external 9.6 MHz or 10 MHz
reference of higher stability. All synthesizer
modules are designed to be easily removed
for programming, calibration and/or repair. The
synthesizer circuitry is distributed between two
printed circuit boards (PCBs) which are isolated
yet interconnected via photo-logic optical
transceivers that effectively eliminate residual
electrical noise between digital and analog
circuitry. Further shielding of the synthesizer’s
RF fi lter circuitry is provided by an internal
shielded enclosure.
OS(R/T)-3H Enhanced Synthesizer
Family Models
Family Models
The OS(R/T)-3H Synthesizer Module is utilized
in both the MT-3 Receiver and Transmitter
product lines. In MT-3 Transmitters, the OS(R/
T)-3H synthesizer provides a modulated, low-
level RF signal to the Power Amplifi er module.
In MT-3 Receivers, the OS(R/T)-3H synthesizer
provides a low noise local oscillator (LO) signal
that either directly drives the mixer circuitry or
fi rst drives a buffer amplifi er which precedes
the mixer circuitry (if a higher LO drive signal
is required for enhanced intermodulation
capability).
in both the MT-3 Receiver and Transmitter
product lines. In MT-3 Transmitters, the OS(R/
T)-3H synthesizer provides a modulated, low-
level RF signal to the Power Amplifi er module.
In MT-3 Receivers, the OS(R/T)-3H synthesizer
provides a low noise local oscillator (LO) signal
that either directly drives the mixer circuitry or
fi rst drives a buffer amplifi er which precedes
the mixer circuitry (if a higher LO drive signal
is required for enhanced intermodulation
capability).
Note: This section of the manual provides
service and operating information for
just the synthesizer modules listed
below. It is important to establish the
correct synthesizer model number,
as documentation is model-specifi c.
The model number can be found on
the synthesizer label, located on the
synthesizer module top cover.
just the synthesizer modules listed
below. It is important to establish the
correct synthesizer model number,
as documentation is model-specifi c.
The model number can be found on
the synthesizer label, located on the
synthesizer module top cover.
This section of manual covers the following
Synthesizers:
Synthesizers:
OST-3H035
29-38 MHz RF output
installed in FM transmitter
OST-3H045
38-50 MHz RF output
installed in FM transmitter
OSR-3H061
50.4-71.4 MHz RF output
installed in FM receiver
All OS(R/T)-3H Enhanced Synthesizer Modules,
regardless of the frequency band, use the same
digital PCB and mechanical construction. There
are, however, signifi cant differences between
the various models when it comes to the
analog PCB. Each model’s specifi c sub-band
of operation within a given frequency band is
determined through SELECT components on the
corresponding analog board.
regardless of the frequency band, use the same
digital PCB and mechanical construction. There
are, however, signifi cant differences between
the various models when it comes to the
analog PCB. Each model’s specifi c sub-band
of operation within a given frequency band is
determined through SELECT components on the
corresponding analog board.