Section 4. Circuit Description - Kenwood AT-120 Operating Manual

SECTION 4. CIRCUIT DESCRIPTION
4
Figure11 shows a block diagram of the AT-120.
Directional Coupler
The directional coupler samples forward and
reflected power from the transceiver to the load. INPUT | DIREC- ANTENNA
Meter Circuit COUPLER
The forward and reflected power sampled by the
directional coupler is used for SWR measure-
ment. Forward power is calibrated with the CAL
control so reflected power is read as SWR. METER
.
CIRCUIT
Band Selector Switch
This selects the band to which the matching
circuit is tuned. In the '"THROUGH" position,
the antenna is connected directly to the trans-
ceiver, by passing the coupler, while still allowing
SWR measurement.
Antenna Coupler
The universal matching circuit is capable of
matching 20 to 3002 loads to the 502 input
impedance.
Figure 11. Meter Power Connection