1-16 (No.RA033<Rev.001>)
2.6.4.2
1st-Mixer circuit
The filtered signal from the front-end circuit is heterodyned with the first local oscillator signal from the PLL frequency synthesizer cir-
cuit at the first mixer (IC403) to become a 58.05 MHz first intermediate frequency (IF) signal.
Fig.12 1st-Mixer circuit
2.6.4.3
1st-IF circuits
The IF1 signal produced by the 1st-Mixer circuit is transmitted through either one of two 1st-IF circuits with different bandwidth.
The signal passes through the WIDE band consisting of D601, D603, XF601, Q601, XF603, D613 and D615 only in Analog_Wide
mode.
Meanwhile,the signal passes through the NARROW band consisting of D602, D604, XF602, Q602, XF604, D614 and D616 in
Analog_Narrow, Digital_Narrow or Digital_Very-Narrow mode.
XF601 and XF602 is 2 pole and XF603 and XF604 are 4 pole Monolithic Crystal Filters (MCF). They are BPF for removing spurious
noise occurring close to the desired signal. The DC switch consists of Q603 and Q604 switches the WIDE and NARROW bands of
the 1st-IF circuits.
Fig.13 1st-IF circuits
136~174MHz
58.05MHz
IF1
IC403
Mixer
1st local
194.05~232.05MHz
SW
SW
SW
50IF1
50IF1
W / N
Q601
MT3S111P
Q602
MT3S111P
Q605
MT3S111P
SW
D601-604
RN142S
Q604
EM6M2
Q603
SSM3J36TUT
D613-616
RN142S
XF601
L7B-0005-00
XF603
L7B-0007-00
XF602
L7B-0006-00
XF604
L7B-0008-00
Summary of Contents for NXR-5700
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