Akai AA-A35 - Tuner Performance

5-2. TUNER PERFORMANCE
5-2-1 General Description
(1) Functions
a) 20-Ch or 16-Ch Random Presetting of Stations
When initialized, discrimates between A45 and
A35/25, and against A45, enables 10 stations each
front (1 to 10) and back (11 to 20) or a total of
20 stations to be preset, while against A35/25,
enables 8 stations each front (1 to 8) and back
(9 to 16) or a total of 16 stations to be preset.
The presetting permits the random storage of
station data irrespective of band, and for FM
stations, the MONO/STEREO segregating data
will also be contained in the storage.
b) Two Tuning Styles: AUTO and MANUAL
The AUTO Scan Tuning that once the UP/DOWN
key is pushed, will continue scanning until a
station is captured, and once it is captured, will
stop scanning, and the MANUAL Tuning that will
scan only when the key is held down, and when it
is released, will stop scanning, are the two tuning
styles enabled.
(LW is shifted in 1K steps for MANUAL and 9K
steps for AUTO.)
c) Switching of MONO and STEREO Receiving
Modes
The MONO/STEREO mode switching function has
been incorporated for FM reception, and is also
included in the stored station presetting data.
5-2-2 Acceptance of Key Input
SINGLE PRESSING
i
2amsec
CONTINUOUS
DEPRESSIONS
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Pele te te ate
Soom: 50 50 50 $0 50
Fig. 5-4
© Chatterings will be absorbed for 24 msec.
© Continuous depressions will be accepted first at 24
msec after the depression start, second at 500 msec
after the first, and then at every 50 msec thereafter.
@ All multiple depressions shall be inhibited. Once a
multiple depression is made, no key inputs will be
accepted until after all of the depressed keys have
been released.
5-2-3 Initial Setting (RST Mode)
a) FL Display:
INPUT SOURCE = pmEser ———>
TUT fo ewacre
TM
scan woos it
Fig. 5-5
b) The received frequency will be at the lowest in the
FM band for each destination:
c) The mode will be STEREO (FM AUTO).
d) The scan mode will be MANUAL.
e) All the preset channels will be at the lowest FM
frequency.
f) The last frequencies of individual bands of the
tuner will be the lowest frequencies.
5-2-4 Status in a Backup Mode
Basically, the status immediately before engaging the
backup will all be sustained, but slight deviations will
be involved, as listed below.
a) When a backup mode is engaged during AUTO
SCAN, the scanning will stop.
b) When a backup mode is engaged in a storage stand-
by mode, the standby will be disengaged.
c) The pre-backup status will be sustained for about
3 weeks.
5-2-5 Active and Non-Active Modes at Tuner
(1) Active Mode
This is a mode after the data has been transmitted to
the microcomputer (A1007A) of AMP to have the
input selector of AMP switched to TUNER, that is, a
mode where all the tuner performance has been
enabled. :
The data for the microcomputer of AMP will be
transmitted from port R4, (A1007T Pin @) when
the BAND, UP/DOWN, and Preset CH keys have
been pushed, and its timing will be as illustrated
below.
Pin @)
R4I (A007 T)
SERVICE MANUAL AA-A35/L: