DANIELS
ELECTRONICS LTD.
TM
VHF Enhanced Extra Wideband Receiver Instruction Manual IM10-VR3H040-AB
5-5
5.3
OS(R/T)-3(A/H) Synthesizer Factory Configuration
The OS(R/T)-3(A/H) Synthesizer is factory configured as follows:
• Internal 9.6 MHz reference selected.
• VCO modulation (via audio processor) enabled (OST TX versions only)
The corresponding internal synthesizer jumper settings are:
Digital
Board
• Jumper JU2 not installed
9.6 MHz internal frequency reference selected
or
• Jumper JU2 installed
10.0 MHz internal frequency reference selected
Analog
Board
• Jumper JU1: 'B' position
Internal frequency reference selected
• Jumper JU2 not installed
Internal frequency reference selected
5.3.1
Jumper Configuration
Solder jumpers are clearly marked on both synthesizer digital and analog circuit boards
.
Refer to
the "OS(R/T)-3(A/H) Digital Board Component Layout (Bottom)" diagram and the applicable
"OS(R/T)-3(A/H) Analog Board Component Layout (Top)" diagram in section 6 for jumper
locations
.
The following list details the required jumper configuration for the two synthesizer
operating modes:
1) Internal
reference
.
Install jumper JU1-B, on the Analog Board (Standard)
.
The internal
temperature compensated crystal oscillator (TCXO) provides the reference signal with a
stability of ±1 ppm from -30°C (Optional -40°C) to +60°C.
2)
External reference input
.
Install jumper JU1-A and JU2 on the Analog Board
.
This
mode is used in applications requiring better than ±1 ppm frequency stability
.
An
external reference signal must be provided at synthesizer SMB connector J1
.
3)
Reference Frequency Select
.
Install jumper JU2 on the Digital Board to select a
10.0 MHz reference frequency
.
When not installed, the reference frequency is by default
9.6 MHz
.
JU2 must not be installed when using the internal 9.6 MHz TCXO reference
.
JU2 is used by the microcontroller to establish the correct reference frequency division
ratio
.
(Located on the Digital Board; The Synthesizer module must be removed to
change jumper JU2.)
Caution
: Care must be exercised when reinstalling the synthesizer module on the Transmitter
Main board or the IF/Audio board
.
Pay careful attention to pin alignment before
pressing the synthesizer module into its mating sockets.