Dmd20 Clocking Options; Clock Selection - Radyne DMD20 Installation And Operation Manual

Theory of Operation

3.6 DMD20 Clocking Options

The following paragraphs define the types of clocking options available to the user at the Front
Panel of the DMD20.

3.6.1 Clock Selection

As shown in Figure 3-9, both the Tx Clock and the Buffer Clock source may be independently
locked to one of the following:
SCT (Internal Oscillator)
SCTE (External Tx Terrestrial Clock)
EXC Clock (External Clock Source)
Rx Satellite Clock (Loop Timing)
EXT IDI (Drop and Insert)
For loop timing applications the SCT Clock Source can be selected to be Rx Satellite Clock.
J19
SD
TT
ST
HIGH STABILITY
High Stability
Oscillator
EXTERNAL
J10
EXT REF
TRANSMIT
RECEIVE
J16
EXT CLK
J8
IDI
CLOCK
RECOVERY
NORMAL
INVERTED
J19
RT
BUFFER CLK
BUFFER CLK POL
RD
DATA POLARITY
INVERT NONE
INV. TERR&BASE
INV. BASEBAND
INV. TERR DATA
3-10
SCTE
SCT
INTERNAL
REF FREQ
SRC
SCT CLK
SRC
SCR
EXT IDI
EXT BNC
SCT
SRC
SCTE
RX SAT
Figure 3-9. Clocking and Polarity Diagram
DMD20/DMD20 LBST Universal Satellite Modem
INVERT NONE
INV. TERR&BASE
INV. BASEBAND
INV. TERR DATA
DATA POLARITY
CLOCK &
DATA
Tx CLK
CLK POL
SRC
NORMAL
INVERTED
AUTO
CLOCK & DATA
RECOVERY
MODULATION
DEMODULATION
TM103 - Rev. 2.5