11.4.1
RECEIVE FREQUENCY SELECT
The first mixer stage of the Receiver Downshifter Module must be configured for the center frequency
of the receive signal. Switches SW1 and SW2 are used to set the receive frequency. The resolution of
the switch setting is 250 Hz and is selected by switch SW1-1. The next switch (SW1-2) has twice the
value of SW1-1, and so-on. The value of each receive frequency setting switch is given in Table 11-2.
The switches are cumulative (the sum of all of the individual switch values gives the total frequency
setting). The frequency selected by SW1 and SW2 must be set for 2 kHz less than the center
frequency of the receive signal, rounded down to the nearest 250 Hz.
For example, a receive frequency of 68.5 kHz would be set as follows:
68.5 kHz – 2 kHz = 66.5 kHz
SW2-5
OFF
64.0
kHz
SW1-4 OFF
2.0 kHz
SW1-2 OFF
0.5 kHz
TOTAL 66.5
kHz
Table 11-2. Receive Frequency Select Switches
Switch Value (kHz)
Switch
ON
OFF
SW1-1
0
0.25
SW1-2
0
0.5
SW1-3
0
1.0
SW1-4
0
2
SW2-1
0
4
SW2-2
0
8
SW2-3
0
16
SW2-4
0
32
SW2-5
0
64
SW2-6
0
128
SW2-7
0
256
SW2-8
0
512
RFL 9785
RFL Electronics Inc.
June 18, 2009
11-6
(973) 334-3100