565 manual
September 2003
Part #74279
Printed in USA
32
Key PTT in SSB
determines whether or not
the ORION can be put into SSB transmit
mode by a closure to the front or rear panel
key jacks. If set to “on”, pressing a CW key
(or some other closure to ground connected
either of the key jacks) will put the radio into
transmit in SSB modes. If set to “off”, the
radio will not be put into SSB transmit in
SSB modes when a closure to ground is
present at one of the two jacks.
(VOX) VOX MENU
Figure 3-3 VOX Menu
The VOX menu is accessible by pressing
the button on the front panel immediately to
the right of the screen next to the “VOX”
annunciator.
VOX Gain
is the gain level required to put
the radio into transmit. This control
determines how sensitive the VOX circuitry
is to input from the microphone.
Anti-Vox
is set to prevent tripping of the
VOX circuitry. Set as needed to prevent
receiver audio through the speaker from
putting the radio into transmit.
Vox Hang
is used to define how long the
VOX remains engaged after the end of a
transmission. This is set to prevent the
radio from cycling back and forth between
transmit and receive during the course of a
normal conversation.
(RX) RX MENU
Figure 3-4 RX Menu
The RX menu is accessible by pressing the
button on the front panel immediately to the
right of the screen next to the “RX”
annunciator.
Sweep Range
is used for setting the range
of the real-time spectrum scope that is
available on the main receiver. There are 5
selectable widths of: 4.5, 9, 18, 36, and 72
kHz.
AGC is Automatic Gain Control and is used
to provide a reasonably uniform output at
audio from incoming signal strengths of
varying intensity.
One of the most useful, revolutionary new
features of ORION is fully programmable
AGC. AGC action can be programmed to
taste on each receiver for
FAST
,
MED
and
SLOW
settings, and a fourth setting,
PROG
,
allows the user to adjust any and all of the
AGC characteristics.
Refer to Figure 3-4 above. To adjust a
given parameter for each receiver, first
select the desired AGC on the receivers
before entering the menu system by using
the AGC button (see
(33) AGC
in Chapter
2).
For
FAST
,
MED
, and
SLOW
: The hang and
threshold parameters are fully adjustable.
AGC hang is the amount of time that the
AGC remains actuated before decay begins.
Threshold is the point at which a signal of a
given strength (expressed in microvolts) will
actuate the AGC system. The threshold
value in the AGC system acts like an IF gain
control for the receiver chain – turn the value
