VHF COMMUNICATIONS ANTENNAS
DME AND TRANSPONDER ANTENNAS
VHF COMMUNICATIONS ANTENNAS
The VHF antenna P/N 2448-88-00 is an
airborne communication antenna capable of
transmitting and receiving signals in the VHF
band from 118 to 156 MHz (extended)
including VDL mode 2.
Aircraft that are equipped for IFR operations
commonly have 2 or 3 separate VHF comm radios,
which utilize separate antennas. When two VHF
comm antennas are installed on small aircraft, the
best coverage is usually obtained with one antenna
on the top and the other on the bottom of the
fuselage. The ELT antenna can cause serious
interference with VHF communications.
WHAT IS AN ELT ANTENNA?
The ELT antenna P/N 2632-82-00 is designed
to transmit emergency signals on the 121.5,
243 and 406 MHz international frequencies.
This low profile, high performance, external
antenna is suitable for high -performance
aircraft.
COMMON MISTAKE IN INSTALLING VHF
COMMUNICATION ANTENNAS
A common mistake is installing a VHF comm too far
forward on the upper fuselage.
DME AND TRANSPONDER ANTENNAS
WHAT IS DME?
Distance measuring equipment (DME) is a radio
navigation technology that measures the slant
range(distance) between an aircraft and a ground station
by timing the propagation delay of radio signals in the
frequency band between 960 and 1215 megahertz (MHz).
WHAT IS TRANSPONDER ANTENNAS?
The transponder in an aircraft is a radio receiver and
transmitter in one box which receives the ATC
interrogation on 1030 MHz and transmits its coded reply
on 1090 MHz.
These two antennas are treated as equals
because they use similar frequencies,
polarization and modulation. The DME and
transponder antennas should be separated
from each other by at least 2 feet.