PAGE 10 AR5000 OPERATING MANUAL
5-10 Volume control (AF GAIN)
The volume control is located to the left of the front panel
underneath the signal meter. It is used to set the required
audio output through the loudspeaker or headphone.
When turned fully clockwise the volume is at maximum,
when rotated fully anti-clockwise the volume is reduced
to minimum.
5-11 ACC 1 accessory number one socket
A front panel accessory socket is located to the lower left
corner of the front panel which provides outputs for audio,
tape motor switching and discriminator.
A standard 8-pin mini-din connector is used (which is widely
available or the optional CR5000 tape lead may be used).
The pin-outs for ACC 1 are as follows:
1 12V d.c. output with a maximum available current of
30mA (useful for feeding electret microphones and other
low power devices). The voltage will fluctuate depending
upon supply voltage being fed to the AR5000.
2 Detector output (without audio filtering), useful for
improving performance of certain decoders such as
pagers etc. The level output is 180mV RMS and
impedance is 100k OHMS or greater.
3 Audio input. The receiver’s audio amplifier stage can
be configured to use signal from an external device rather
than from its own receive circuits. This permits
break-out of signal for processing (DSP etc) which is then
reapplied to the receiver for amplification. The input circuit
is configured for a level of 180mV at a nominal impedance
of 100k OHMS.
As the internal audio path needs to be cut as part of the
break-out set-up, the microprocessor has to be
configured accordingly. To select EXTERNAL AUDIO
INPUT press
then press the
key
four times to display “
AUDIO INT
AUDIO INT
AUDIO INT
AUDIO INT
AUDIO INT
”. Rotate the
SUB DIAL
to display “
AUDIO EXT
AUDIO EXT
AUDIO EXT
AUDIO EXT
AUDIO EXT
” then press
. The usual
sound from the receiver will be muted until an external
audio signal is applied (fed back in).
Of course, the set’s own audio may be fed out through
the ACC 1 socket and back in again which increases the
receivers flexibility under certain professional monitoring
applications.
Note: At high volume levels, a low level leakage of internal
audio signal may still be heard from the receiver’s
speaker... this is normal and does not represent a fault
(or problem).
4 & 5 Tape record motor switching using a non-polarised
photo-MOS relay. The switched output is designed for
low voltage (12V) d.c. with a maximum current of 350mA,
the insulating voltage is 40V. The switch-on-impedance
is 1.2 OHMS.
6 High level audio output. The AR5000 provides both
high and low level audio output for feeding tape recorders
and other remote devices, the output is independent of
volume control level. Pin 6 provides a level of 700mV
RMS @ 600 OHMS, ideal for line output.
7 Low level audio output. Pin 7 provides a level of 2mV
RMS @ 600 OHMS, ideal for microphone input of tape
recorders.
8 Ground.
5-12 Headphone socket
This quarter inch (6.3mm) socket is located on the left
hand side of the front cabinet directly underneath the power
and
keys. A pair of headphones or earphone may
be connected with an impedance of 8 OHMS or greater.
When this headphone socket is used, the internal speaker
and any external speaker will be automatically
disconnected.
5-13 Front panel keys
- POWER
This rectangular shaped plastic key located in the upper
left corner of the front panel switches the set On/Off.
- FUNCTION
This key is located to the upper left of the front panel and
selects SECOND FUNCTION of the front panel keys.
When pressed a reverse “FUNC” appears in the top left
of the LCD. The FIRST function of the keys are printed
on their faces (in orange for words and white for numbers),
the SECOND functions are printed in white directly above
the corresponding key.
For example, the select KEY LOCK, press
followed by
If you wish to cancel “FUNC” press
a second time,
or
or
or tune the receiver using the
MAIN
DIAL
or
SUB DIAL
.
