Attenuator - AOR AR8000 Operating Manual

Small tuning steps of 50 Hz or 100 Hz should be used for tuning in LSB and
other similar modes USB & CW.
The AR8000 being a hand held wide band receiver cannot offer the
receive performance of a dedicated short wave receiver such as the AOR
AR3030 or base wide band receiver AOR AR3000A. This is due to the
limitation of size, as a result the receiver's AGC (Automatic Gain Control)
circuitry bandpass circuits and reference stability cannot be as complex.
The AR8000 will however provide adequate results for oceanic, ship to
shore and amateur band listening etc.
The SSB frequency display is not offset (like some other units). However being
such a compact wide band receiver, it will not be unusual for the SSB display
to be a few hundred Hz off frequency when listening to known frequencies such
as VOLMET (airband weather forecast service). For example the European
5.5050 MHz VOLMET service may appear between approximately 5.5045 and
5.5055 MHz... this is considered normal.
USB
Upper Side Band - The same comments apply as for LSB. By convention,
Radio Amateurs also use USB above 10MHz.
All long range shipping and oceanic air traffic (as well as long range military
aircraft) use USB. DATA modes such as RTTY, SITOR, PACKET, FAX etc
may be resolved using USB.
CW
Continuous Wave - Often referred to a Carrier Wave or Morse code "dots and
dashes". Commonly used on the short wave bands by radio amateurs toward
the lower end of each band allocation. Some commercial use is still made by
shipping etc although its use is being phased out due to the introduction of
automated stations.
6-12 [ATT] Attenuator ON/OFF
The attenuator adds 10dB of signal reduction to the RF input stages of the
AR8000 to reduce the possible effects of signal overloading due to connection
to an external aerial or when the receiver is used in close proximity to strong
transmissions.
The AR8000 has two settings for ATT (attenuator), On and OFF. When the
attenuator is ON, the legend "A" appears on the top
line of the LCD in the seventh position from the left
hand side.
To toggle the attenuator On/Off while in VFO mode
press [FUNC] [1] the legend "A" confirms selection
and incoming signals will be reduced in strength. To
toggle On/Off again just repeat the sequence [FUNC]
[1], the legend "A" is extinguished when the