588 manual
Second release – August 2007
32
Part #74409
Printed in USA
FSK OPERATION
Selection of the FSK mode will allow the
OMNI-VII to operate true FSK RTTY. The
FSK circuitry is controlled through the ACC
1 jack on the rear panel of the transceiver.
Pin 5 on the ACC 1 rear panel jack is the
MARK/SPACE or FSK input. This input is
typically connected to the FSK output on a
modem or terminal unit. The OMNI-VII
receives FSK using lower sideband. The
center of the filter passband is preset so any
bandwidth filter used will be centered on the
standard FSK MARK/SPACE 2125/2295 Hz
tones.
The OMNI-VII display indicates the transmit
MARK frequency. There is also user control
called FSK TX DATA in the menu for
selecting whether the MARK is the low tone
or high tone (the standard is low tone). This
allows the transceiver to be used with either
TTL or open-collector keying schemes.
The monitor function is available in FSK
mode and may be used to monitor the
transmitted tones. See (25) MIC/MON is
Section 2.
ON- SCREEN STATUS
MESSAGING
There are several status messages that can
appear at the upper right of the radio screen
under certain circumstances to warn the
operator of a potential problem or to inform
that an operation the transceiver cannot
process is being attempted.
NO AUTO 6M – This message appears on
the screen if an attempt is made to use the
TUNE button to actuate the optional
automatic antenna tuner on the 50 MHz
band. To remedy, go into the menu, turn the
autotuner to OFF and then the TUNE and/or
PWR buttons can be used to generate a
carrier on 50 MHz.
HIGH CURRENT - The OMNI-VII is
equipped with a current limiting circuit. At
23 amps current draw HIGH CURRENT will
appear on the upper right of the screen. At
25 amps, an internal silicon controlled
rectifier will open and power to the radio will
be shut off. Radio power can be restored by
cycling the power switch or your 13.8 Vdc
power source.
OVER TEMP – OMNI-VII uses an internal
temperature gauge on the final amplifier. If
the temperature exceeds 70 degrees C, this
message will appear on the screen and the
transmitter will be disabled for a minimum of
one minute. After one minute, the firmware
will perform a temperature status check on
the final amplifier. If the temperature has
reached 65 degrees C, the transmitter will
be re-enabled and the OVER TEMP
message will disappear from the screen. If
the radio is still over 65 degrees C after one
minute, the OVER TEMP message will
remain on the screen and the transmitter will
continue to be disabled until the temperature
drops to that point.
TUNE FAILED – shown momentarily if the
radio attempts to tune with the automatic
antenna tuner and the tuner cannot tune, or
if the radio is set up to use the autotuner and
the tuner does not “answer” when queried
by the radio. When TUNE FAILED occurs,
the radio will automatically switch the
automatic tuner to BYPASS.
ON-SCREEN BARGRAPH METER
OMNI-VII employs a digital bargraph meter
on the transceiver screen.
When in use on receive, the bargraph S-
meter indicates received signal strength.
The S-meter is calibrated to read S9 with a
50 uv signal at the antenna connector.
Previous transceivers were calibrated to
register S9 with a 50 uv signal without pre-
amp or any attenuation engaged. OMNI-VII
has been programmed to register an
accurate strength of the signal regardless of
internal amplifiers or attenuation.
On transmit, the bargraph meter can be
used to monitor either transmit output power
or SWR. See the description of
TX METER
elsewhere in this manual.
OPERATING SPLIT FREQUENCY
Operating split frequency is commonly used
in DX operation on the HF amateur radio
bands. Stations will often transmit on a
clear frequency while listening for callers on
another nearby frequency.
Let’s say a DX station is calling on 14.195
MHz and is telling callers “listening up 5 to
10”. You in turn should call on 14.200 to
14.205 MHz and listen for a reply on 14.195.
