Apr/2006 - Honeywell KHF 1050 System Installation Manual

2.C. Antenna Coupler Tune Fault
The antenna coupler must tune the antenna prior to being able to make a
transmission. Keying the microphone on a previously untuned channel initiates a
tune sequence that can last up to 30 seconds. (If the channel has been previously
tuned, the retune time typically takes less that 50 msec.) In the event the antenna
coupler cannot find a tune, a tune-fault will be indicated. The manner in which the
tune-fault is manifested to the pilot is controller and set-up dependent. In addition
to any visual indication, in a system that has the tune tone enabled, a tune fault will
be indicated by the steady tune-in-progress tone changing to an intermittent
beeping tone.
Visual indications:
• Using a PS 440 Controller, the frequency digits will flash to indicate a
tune-fault.
• With a MC-850, a "TUNE FAIL" message will appear.
• When using a RM-855 Controller, no visual indication is available. The beeping
tone is the only tune fault indication.
To clear the tune fault, either change the operating frequency or momentarily press
the PTT. It is advisable to try up to three tune attempts to tune the antenna to a
particular frequency. If repeated tune faults are observed, refer to the Tuning
Failure Section in
2.D. Receiver Performance Check
1. If an operating frequency is properly displayed on the controller, listen to the
speaker or headphones. Ensure that the aircraft audio panel is properly set to
select the HF audio.
2. Select the USB Voice (UV) mode, SBH type squelch. (SBH is the default
squelch type. If using an RM855, only the SBH type is available.) Adjust the
squelch level to OFF. Adjust the volume control on the PS440 controller, and/or
the volume control on the audio panel. Depending on the frequency or channel
selected, a signal may be heard - or perhaps just atmospheric static.
NOTE: If the aircraft is located in a metal hangar, both signals and noise may
be weak. It is advisable to have the aircraft outside the hangar to
perform the receiver or transmitter tests.
Select a channel with a known usable signal. One possibility is one of the
time-and-frequency standard stations operating on frequencies of 2.5 MHz, 5
MHz, 10 MHz, 15 MHz, or 20 MHz.
Revison 2
N
KHF 1050 SYSTEM INSTALLATION MANUAL
"Table 1004 - Fault Isolation Checklist"
23-10-09
.
Page 1006

Apr/2006