Technical description
4-20 HF SSB Transceiver 9323/9360/9390/9780 Technical Service Manual
Clarifier
The operation of the clarifier control, when selected on the front panel of the
control head, is read by microprocessor IC2 via IC1 [1 04-02974]. The
information is then sent via the external I
2
C bus [1 04-02976 Sheets 1 and 2].
For each clarifier step detected, the microprocessor IC101 [1 04-02976]
reprograms synthesiser IC13 [1 04-02972 Sheet 1] or IC10 [1 04-03135
Sheet 1], shifting VCO2 in 10 Hz steps from the nominal frequency. The clarifier
has a range of ±50 Hz for channels 2 MHz to 5 MHz and then increases with
frequency at a rate of ±10 ppm above 5 MHz.
The operation of the clarifier is achieved by varying both VCO2 and the reference
frequency dividers according to the "look-up" table in the transceiver’s operating
system. Thus the phase comparison frequency is not constant, but varies from 1.1
to 2.0 kHz.
An audible indication is given when the clarifier reaches its upper or lower limit.
The clarifier automatically resets to the mid frequency when another channel is
selected or the transceiver power is interrupted.
To Next Page
Loading...
Need help?
General
