Revision 0 10640I00.Slk - Honeywell KHF 1050 System Installation Manual

Preliminary - Subject to Change Without Notice
In the event that the operating frequency selected had
previously been tuned by the KAC 1052 Antenna Coupler, the
antenna coupler will utilize stored tune information and
match to the antenna in less than 50msec. However, changes
in antenna impedance can occasionally result in the KAC
1052 needing to retune on a previously tuned frequency.
3. Upon completion of the tune cycle, the tune indication
will disappear and the display will return to a normal
recieve window. The receiver audio will likely be stronger
than it was prior to tuning the antenna and it may be
necessary to readjust the squelch if there is significant
noise on the channel. The system is now ready to transmit
voice communications.
4. In order to ensure good audio quality of the transmitted
signal, a microphone-ground-loop test is recommended. To
check for microphone ground loops, select the AM mode on
an unused frequency. Key the system with no modulation,
preferably covering the microphone element with your hand.
Listen for any squeal or popping sound in the speaker or
headphones. A squeal or popping sound tends to indicate
that a microphone ground loop exists. Microphone ground
loops will result in distorted audio. Such a ground loop
is usually the result of the microphone audio low line
being tied to airframe ground at multiple points.
5. Listen to the sidetone in the headphones or speaker while
transmitting, both in USB Voice (UV) and in AM. A raspy
sound may indicate that RF interference is feeding back
into the HF or audio system.
6. While transmitting a voice test message in USB Voice (UV),
observe other electrical equipment in the aircraft and
note any interference observed that correlates to the HF
transmission.
7. Voice communications should be established with a ground
station or another aircraft. See Section 7.B.(4)(b).
Revision 0
10640I00.SLK
N
KHF 1050 SYSTEM INSTALLATION MANUAL
23-10-09
Page 1008
Mar/2003