3-6
To the band filter circuit
HP F
LPF
HP F
BPF
RF
AMP
BRF
HPF
D3252,D3253
HP F
ATT BP F
LP F
BPF
RF
AMP
LP FLPF
HP F
HP F
BP FATT
HP F
13.9-20.9MHz
f c=500MHz
1.6-2.0MHz
BW=20MHz
3.5dB
2.0-3.4MHz
6.9-13.9MHz
1LO
3.4-6.9MHz
BW=10MHz
144-148MHz
430-450MHz
HF BAND ->
VHF/UHF BAND ->
BW=20MHz
0.03-1.6MHz
UHF: 524.487-594.487MHz
40.0-60.0MHz
1.6-74.8MHz
60.0-74.8MHz
HF/VHF: 124.517-324.487MHz
20.9-40.0MHz
fc=500MHz
f0=146MHz
fc=74.8MHz
1st MIXER VUHF/HFTX
From the 2nd TX IF circuit
FI3051FI3052
IC3051
D3272
6dB
IC3031
MAIN UNIT
1ST TX IF CIRCUIT (MAIN UNIT)
The 1st TX IF signal from the 2nd TX IF circuit is applied to
the 1st TX mixer (D3252 and D3253), then mixed with the 1st
TX LO signal, resulting in a signal at the TX frequency.
The converted TX signal is applied to the TX amplifi er circuit.
• While operating on the HF, 50 MHz and 70 MHz bands -
The TX signal is passed through the LPF (L3261 to L3263,
C3216 to C3267) and one of the BPFs, depending on the
operating frequency, to remove unwanted signals.
The fi ltered signal is applied to the TX power amplifi er cir-
cuit.
• 1st TX IF CIRCUIT
• While operating on the 144 MHz and 430 MHz bands -
The TX signal is passed through the LPF (L3261 to L3263,
C3216 to C3267) and BRF (D3272, L3271, L3272, C3271 to
C3273).
• 144 MHz band signal
The TX signal is passed through the 3 dB attenuator (R3035
to R3037) and 146 MHz BPF (MAIN UNIT: L3032 to L3035,
C3036 to C3046), and then amplifi ed by the RF AMP
(IC3031).
The amplifi ed signal is applied to the TX power amplifi er cir-
cuit.
• 430 MHz band signal
The TX signal is passed through the 3.5 dB attenuator (R3052
to R3054), and amplifi ed by the RF AMP (IC3051). The am-
plifi ed TX signal is sequentially passed through the BPF
(FI3052), LPF (L3052, C3053, C3054) and BPF (FI3051).
The fi ltered signal is applied to the TX power amplifi er cir-
cuit.
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