Kenwood KT-990D Service Manual page 8

Active Reception Circuit
START
Tuning operation start
No Manual mode
Preset tuning
Yes] Auto mode
RF SELECTOR RF SELECTOR
DISTANCE DISTANCE
IF BAND IF BAND
NARROW NARROW
Tunung start
Auto-scanning
Up/Down
_ Tuni ti t
Radio wave
detected?
Yes
Auto-scanning
stop
Field strength
measurement
Yes
RF SELECTOR
DIRECT
interference
detection
Interference
present?
iF BAND IF BAND
WIDE NARROW
Tunung operation End] If the ANT Input is very small (less than 1OdBF)
the Forced Narrow mode is activated regardless
of the presence or absence of interference.
RF SELECTOR
DISTANCE
Present