Family Radio CTCSS 'Type 2' Encoder and Decoder
CMX808A
1.4
External Components
C1
C2
C3
C4
C5
C6
C7
C8
22pF
22pF
0.1µF
0.1µF
100pF
0.1µF
Note 1
0.1µF
±20%
±20%
±20%
±20%
±20%
±20%
±20%
±20%
R1
R2
R3
R4
1MΩ
22kΩ
100kΩ
Note 1
±5%
±10%
±10%
±10%
X1
4.0MHz
±100ppm
Note:
1.
R3, R4, C5 and C7 form the gain components for the Rx Input Amplifier. R4 should be
chosen as required by the signal level, using the following formula:
Gain
=
−
R3
R4
C7 x R4 should be chosen so as not to compromise the low frequency performance of this
product.
Figure 2 Recommended External Components
2003 CML Microsystems Plc
6
D/808A/6