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after hearing the last dit. With mode B, you
start the same, then let go of both paddles
after hearing the second dah. The C will
self-complete in mode B; in mode A the last
character sent will be the second dah.
The CW keyer can also be turned off from
the front panel using the SP button but
mode A or mode B can only be selected via
the menu. See (29) SP/VOX in Section 3.
CW RISE/FALL
Available settings: 3 to 10 ms.
CW RISE/FALL allows the operator to adjust
the rise and fall time of the transmitted CW
envelope. The adjustable values are 3 ms
to 10 ms, depending on whether the internal
keyer or external keying is used, and the
speed at which the internal keyer is set. The
default value is 5 ms. Lower values like 3
ms will result in a "harder" keying sound with
a quicker slope from keying initiation to full
envelope and back. Higher values result in
more gentler slopes for the CW transmit
envelope on the "make" and "break" and
result in a softer transmitted CW note.
Use of ALC to control the output power will
corrupt the attack time of the CW character.
For instance, a CW wave is generated to
produce a character with 1 volt peak and a 6
ms rise time. If there is 6 dB too much gain
in the transmit loop, ALC will be reached
when the CW wave reaches .5 volt. At that
point the rise time is 3 ms, not 6 ms. That
change in the rise time will happen on the
first character, and the ALC time constant
will determine what the change in rise time
will be over the transmission. This may be
improved by changing the transmitter gain,
the level of the CW wave or both.
The OMNI-VII uses the voltage derived from
the bridge circuit as a reference for 100
watts output. Each band is calibrated in
production. This sets the required DSP
output. The CW waveform is generated in
DSP and uses a raised cosine for the attack
and decay. The level of the DSP waveform
for the power selected can be calculated
from the level given for 100 watts before the
key is pressed. The keyed signal is
adjusted slightly to compensate for
variations in load impedance. The attack
588 manual
Part #74409
Printed in USA
time is calculated as the time required for
180 degrees of the cosine.
AUTO SWEEP
Available settings: ON, OFF.
The momentary sweep scope on OMNI-VII
can automatically re-sweep without pushing
the SWP button.
When turned to ON, once the red cursor
present on the sweep display is moved to
either edge of the shown swept range, the
sweep function will re-enable without
pushing the SWP button again.
SWEEP RANGE
Available settings: 3, 30, 300 kHz.
The SWEEP RANGE setting determines
what range of frequencies are swept when
the SWP button is pushed.
See (15) SWP in section 3 of the manual for
complete information on how the momentary
spectrum sweep operates on OMNI-VII.
VOX TRIP
Available settings: 0-100%
This control determines how easily signal
input into the microphone will open (trip) the
VOX circuitry and put the radio in transmit in
SSB, AM, and FM modes. The higher the
value, the easier the radio goes into transmit
when talking into the microphone.
ANTI-VOX
Available settings: 0-100%
ANTI-VOX is used to inhibit receiver audio
from tripping the VOX circuitry. Higher
values require more noise to activate VOX,
lower value require less noise to activate
VOX.
VOX HANG
Available settings: 0-100%
VOX HANG is used to determine how long
the transmitter remains keyed after VOX
activity before the radio switches back to
receive. This is to prevent the radio from
cutting back and forth between transmit and
receive with each syllable and/or word.
Higher values keep the transmitter keyed for
longer periods of time.
Second release – August 2007
23
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