Circuit Descriptions and Serial Control Information ...... 2
Control bits
Element
Notes
Post-Process Gain
A fixed 2.0dB gain stage.
15
Pre-emphasis
A selectable pre-emphasis stage set around
1.0kHz, with a characteristic of 6dB per octave.
It is available for use when transmitting data signals
such as FFSK. See Table below for Powersave
information.
Deviation Limiter
and
A pre-set amplitude limiting stage for deviation
control.
Post-Deviation Limiter Filter
This lowpass filter which is selected with the
Deviation Limiter, is adjustable to Narrow (2550Hz)
and Wide (3000Hz) bandwidths, allowing for
different channel-spacing requirements.
16
– Narrow filter bandwidth,
cut-off = 2550Hz.
– Wide filter bandwidth,
cut-off = 3000Hz.
0
1
CTCSS/Data Input
17
– Disable Input path to Mixer system
– Enable Input path to Mixer system
0
1
15 18 19
Pre-Emphasis
Limiter and Post-Dev LPF
Drive Selected
X
0
0
1
1
1
0
0
0
0
1
1
Powersaved
Powersaved
Enabled
Powersaved
Powersaved
Powersaved
Enabled
Enabled
Powersaved
Powersaved
Test Path
Post-ProcessPath
Post-Process Path
Post-Process Bypass
Bias
1
X
X
VCO Reference Drive Attenuator
20 21 22
The in-line control attenuator for the VCO reference
channel drive output.
– Gain Set
-28dB
-24dB
-20dB
-16dB
-12dB
-8.0dB
-4.0dB
0.0dB
0
1
0
1
0
1
0
1
0
0
1
1
0
0
1
1
0
0
0
0
1
1
1
1
VCO Reference Drive Amplifier
23 24 25 26
The in-line control amplifier/attenuator for the VCO
reference channel drive output.
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
– Gain Set
-2.75dB
-2.50dB
-2.25dB
-2.00dB
-1.75dB
-1.50dB
-1.25dB
-1.00dB
-0.75dB
-0.50dB
-0.25dB
0dB
0.25dB
0.50dB
0.75dB
1.00dB
Output Drive Control
Used in conjunction with Bit 36 to control output
27
functions.
Reference ...... Figure 4
7
CMLMICRO [ CML MICROCIRCUITS ]
