Technical Manual

TAG11263-1
RF AMPLIFIER
TR403
MIXER
AE401
AE402
2nd OSC.
MIXER
455kHz
TR401, TR402
21.4 MHz
CER
FL402
IC401
MIXER, IF AMP & DET.
TR410
1st OSC.
FL401
IF AMP
XL402
XL401
455kHz
CER
FL403
CV404
(OPTIONAL)
TR404
TP403
IMAGE
FILTER
GND GND
CV407
CV406
CV405
TP405
RSSI
DET
DELAY
FL404
DECODER
TP401
SINAD
FSK
COMP.
FILTER
QUICK
CHARGE
AMP
PHASE
1V
REG
TR406
1V
SUPPLY
1V
TP402
INT.
REF.
RXEN
LOWB
AGC CONTROL
TLA 852/FLA 872
TM1205 Issue 2Page 3 - 4
Figure 3.2: Receiver Block Diagram
3.2 DUAL CONVERSION RECEIVER
The incoming RF signal is received by the aerial AE401/AE402 which is tuned by
CV404. Capacitors C401, C405 and inductor L416 provide matching to RF amplifier
TR401, TR402. The amplifier, typically, yields a voltage gain of 20 dB. R401 and
R402 provide DC bias.