Pre-Selector - Furuno FS-1575 Service Manual

BAND-4: 8000 to 17999.9 kHz

2. Pre-selector

The pre-selector couples the two stages of resonator with a capacitor to configure
Band-pass filters with narrow bandwidth.
It switches the capacitance of capacitor inserted parallel to the resonator to tune to
the received frequency. For switching, frequencies between 1450 and 4999.9 kHz are
divided into 36 bands.
Pre-selector Frequency Division (kHz)
1450 to 1499.9 1800 to 1849.9
1500 to 1549.9 1850 to 1899.9
1550 to 1599.9 1900 to 1949.9
1600 to 1649.9 1950 to 1999.9
1650 to 1699.9 2000 to 2049.9
1700 to 1749.9 2050 to 2099.9
1750 to 1799.9 2100 to 2149.9
Note) Insertion loss is 6dB or less in the band of 3.0999 MHz or less and 4dB or less in
the band of 3.1 MHz or more.
PRESEL: 2200 to 2249.9 kHz
CONFIDENTIAL (internal use only)
This confidential document is used only by FURUNO authorized persons.
It is strictly prohibited to reproduce the document in whole or in part without prior written permission of FURUNO.
0dB
Table 7.3.2 Pre-selector Frequency Division
2150 to 2199.9 2500 to 2549.9
2200 to 2249.9 2550 to 2599.9
2250 to 2299.9 2600 to 2699.9
2300 to 2349.9 2700 to 2799.9
2350 to 2399.9 2800 to 2899.9
2400 to 2449.9 2900 to 2999.9
2450 to 2499.9 3000 to 3099.9
0dB
7-39
7.3 Receiver Circuit
BAND-5: 18000 to 29999.9 kHz
3100 to 3249.9
3250 to 3349.9
3350 to 3549.9
3550 to 3699.9
3700 to 3947.9
3950 to 4199.9
4200 to 4549.9
PRESEL: 4200 to 4549.9 kHz
0dB
4550 to 4999.9
0dB