The transmit frequency will automatically track the receive frequency
when tuning, providing for simplex operation. To verify the transmit fre-
quency, press and hold the ENT button located on the end of the right
knobs. RX and TX will be illuminated on the display and the transmit fre-
quency will be displayed in the upper row.
3. Tune the antenna coupler. Momentarily press the push-to-talk button
to initiate antenna tuning. During the tuning process the TX lamp (just
below the TEST button) will flash and the frequency numbers will blank.
A tune tone will be heard, if enabled during system installation. When
the TX lamp stops flashing and the frequency reappears, the antenna
tuning cycle is complete and you are ready to transmit on the selected
In the event the antenna coupler is unable to tune to the selected fre-
quency, the frequency digits and the TX lamp will flash. If enabled, a
tune tone will sound intermittently. Press push-to-talk once or twice to
clear the fault or initiate another tune cycle attempt. The fault may also
be cleared by selecting a different frequency. After the new frequency is
selected, press the push-to-talk to tune the antenna coupler.
NOTE: The KHF 1050 stores the antenna coupler tune information for
previously tuned frequencies. If the antenna coupler was previously
tuned for the current frequency (or nearby frequency) the antenna cou-
pler may not need to be tuned and transmission may begin immediately.
It is advisable to always press the push-to-talk button after selecting a
new frequency to initiate antenna tuning. Otherwise poor reception may
be experienced or it may not be possible to hear a ground station which
SEMI-DUPLEX DIRECT TUNING
If operating in a situation that requires a
transmit frequency that is different than the
receive frequency (semi-duplex) a different
transmit frequency may be tuned.
1. Turn the left outer knob to FREQ. See
Figure 5. The frequency shown in the
upper row of the display is the receive fre-
quency indicated by the RX on right of the
2. Press and hold the ENT button.
3. Momentarily press the FUNC button,
then release the ENT button. The transmit
frequency can now be tuned independent of the receive frequency. Note
that TX is now illuminated on the display indicating that the displayed fre-
quency is the transmit frequency. See Figure 6.
Revision 0 Mar/2003
KHF 1050/PS440 Pilot's Guide