Furuno FS-1503 - 1 Lo PLL VCO; Oscillation Frequency on each Band

2-16
T
C
CR505 CR506
CR508 CR507
C
C
C
Q503
12 V
VCO OUT
VCO CONT
R519
R520
R522
H/L
(Changing capacitance)
(L)
C
(C1) (C2)
(C4)(C3)
T501 - 504
BAND Select
(f
VCO
)
f
VCO
=
(C1 + C2) + (C3 + C4)
(C1 + C2)
×
(C3 + C4)
L
×
2
π
1
Note)
· C2, C4 Variable with H/L Signal
· C1, C3 Variable with VCO CONT
T501 - 504
·
C = 1000 pF
·
CR506 to 508 = 1SV232
(Variable capacity diode)
Figure 2-8 1Lo PLL VCO
Table 2-6 Oscillation Frequency on Each Band
Band Set Frequency VCO Output Frequency
1-L 0.1 to 2.99999 MHz 54.55500 to 57.45499 MHz
1-H 3.0 to 5.99999 MHz 57.45500 to 60.45499 MHz
2-L 6.0 to 9.49999 MHz 60.45500 to 63.95499 MHz
2-H 9.5 to 13.49999 MHz 63.95500 to 67.95499 MHz
3-L 13.5 to 17.49999 MHz 67.95500 to 71.95499 MHz
3-H 17.5 to 21.49999 MHz 71.95500 to 75.95499 MHz
4-L 21.5 to 25.49999 MHz 75.95500 to 79.95499 MHz
4-H 25.5 to 29.99999 MHz 79.95500 to 84.45499 MHz
Note)
The above table shows the VCO output frequency on TLX and FAX modes. Add an
offset frequency for other modes.
Reference)
PLL1, PLL3, DDS and BAND data are set in the following order every time
set frequency and/or class of emission is changed.
1) DDS data setting
2) PLL1 data setting
3) SYN shift register data setting (1Lo Band data)
4) PLL3 data setting