Table of Contents
Advertisement
SECTION 3
3-1 GENERAL
An 8-bit microprocessor controls the AT-141. The antenna tuner matches the antenna system to the transceiver by using four
kinds of detector circuits.
(1) FORWARD POWER DETECTOR
(2) SWR DETECTOR
(3) PHASE DETECTOR
(4) IMPEDANCE DETECTOR
Detailed descriptions for each circuit as follows.
TRANSCEIVER
FORWARD (FWD)
POWER DETECTOR
CIRCUIT
3-2 FORWARD (FWD) POWER DETECTOR CIRCUIT
This circuit ensures the input power from the transceiver is
low enough to be handled by the attenuator within the tuner.
The RF power from the connected transceiver is detected at
the power detector (L1) and then convert into a DC voltage.
The converted voltage is applied to the CPU (IC15, pin 62)
and then analyzed input RF power.
• FORWARD POWER DETECTOR CIRCUIT
L1
INPUT
(FROM RL1)
D1
R13
CIRCUIT DESCRIPTION
RL1
ATTENUATOR
PHASE DETECTOR
CIRCUIT
IMPEDANCE
DETECTOR
CIRCUIT
FWD
DATA
To RL2
C2
R9
R72
R8
C3
C4
C178
To CPU
(IC15, pin 63)
RL2
SWR
DETECTOR
CIRCUIT
TO
RL1, RL2
Z
PH
SWR
DATA
DATA
DATA
LOGIC
CIRCUIT
3-3 SWR DETECTOR CIRCUIT
The SWR detector detects the reflected signal from the
antenna system.
The reflected signal is detected at the SWR detector (L4)
and then converted into DC voltage at D13, D14. The con-
verted voltage is applied to the CPU (IC15, pin 62) and the
CPU controls the setting of the coils and capacitors in the
matching network.
• SWR DETECTOR CIRCUIT
INPUT
(FROM RL1)
B - 3 - 1
ANT
MATCHING
NETWORK
LED
CIRCUIT
R30
R29
L4
OUTPUT
(TO RL2)
R28
R31
C18
D14
R36
R37
D13
C21
To CPU
(IC15, pin 62)
Advertisement
Table of Contents
