AR5000 OPERATING MANUAL PAGE 19
Providing the AUTOMODE facility has been engaged
(so that the “AUTO” legend is displayed above the right
hand digit of frequency readout), you may monitor the
frequency or tune the receiver using the
MAIN DIAL
or
SUB DIAL
. The AR5000 microprocessor will automatically
select the appropriate tuning increment, mode and I.F.
bandwidth from the detailed automode bandplan data
pre-programmed into the receiver (specific to each world
market area). If automode is not active, press and hold
the
key for more than one second. The “AUTO”
legend on the LCD will confirm operation.
6-5 Correction of frequency during input via
the numeric keypad
Should a mistake be made while entering frequency via
the keypad in VFO mode, the
key may be used to
backspace delete the entry from the right hand side. If all
digits are deleted, the display will return to the previous
frequency.
6-6 Selecting tuning step (increment)
The specification for channel occupancy, step (separation)
and mode are decided by and allocated by departments
of Government following International discussions.
Not surprisingly the allocation of frequency bands are not
the same all over the world and channel separation (step)
varies from band to band. As an example, the channel
separation (step) for the medium wave band in Europe is
9 kHz while in the U.S.A. it is 10 kHz.
For the above reason it is necessary to alter the STEP
size according to local bandplan conventions. The
AR5000 has been pre-programmed at the factory with all
the bandplan data (specific to each market area) so that
the AR5000 will automatically select the appropriate step
size and mode for the frequency chosen. This greatly
simplifies operation of the receiver while you are
familiarising yourself with all the facilities.
The pre-programming of step size may be manually
overridden so you may choose alternative settings at will
or when bandplans are updated.
The tuning step (often referred to as the tuning rate or
increment) is usually automatically set by the AR5000
using the automode bandplan information - WHEN
AUTOMODE IS ENGAGED.
To enable AUTOMODE, press and hold the
key
for more than one second, the “AUTO” legend will
appear on the LCD above the right hand (last) digit of
the frequency readout to confirm selection.
Most known step sizes are available with the exceptions
such as TV channels which are allocated with 6MHz or
4MHz spacing. There will be occasions when you may
wish to change the automode step selection so it is
possible to customise the step size used by the
MAIN DIAL
and
SUB DIAL
(step size may also be programmed in search
mode).
MAIN DIAL
MAIN DIAL
MAIN DIAL
MAIN DIAL
MAIN DIAL
Only when the VFO mode is engaged may the
MAIN DIAL
be used to select the receive frequency. Rotate the
MAIN DIAL
to change the receive frequency, alternatively
the
and
keys can be used. Frequency will
step in the pre-programmed step size as dictated by the
automode bandplan data.
The
key enables the step size for tuning the
receiver to be customised.
Press the
key, the flashing legend “STEP” on the
LCD confirms that the STEP SELECT MENU has been
activated. If the legend ”
AUT
AUT
AUT
AUT
AUT
” is displayed above-right,
then the step will automatically be determined from the
automode bandplan data. As soon as another selection
is made automode is cancelled.
At this point the
SUB DIAL
may be rotated to select a new
step size for the
MAIN DIAL
from the following list: 0.001
kHz (1 Hz), 0.010 kHz (10 Hz), 0.050 kHz (50 Hz), 0.100
kHz (100 Hz), 0.500 kHz (500 Hz), 1.000 kHz, 5.000kHz,
6.250 kHz, 9.000 kHz, 10.000 kHz, 12.500 kHz, 20.000
kHz, 25.000 kHz, 30.000 kHz, 50.000 kHz, 100.000 kHz
and 500 kHz.
Once the selection has been made press
to accept
any changes. If you wish to abort step size selection press
In addition, unusual step sizes may be entered using the
numeric keypad (i.e.
for 22 kHz or
for 200 Hz). Acceptable input range is
1 Hz to 999.999 kHz.
Important: The receive frequency must be divisible by
the step size or the receiver will not receive the desired
frequency or follow the bandplan.
Examples:
Receive frequency / Step size must = round number
433.200MHz/20kHz = Divisible (433200 / 20 = 21660 all okay)
152.010MHz/20kHz = Not divisible (152010 / 20 = 7600.5 so must
use the special STEP-ADJUST
FACILITY detailed section 6-7
of this manual).