User's Manual

5-5
5-2.6. INSTALLATION AND OPERATION
5-2.6.1 Selecting 400 to 420 MHz Frequencies:
Press the [FREQ] key (keypad [1]) to select frequency entry mode. To select a frequency,
enter the desired frequency.
5-3. ECS- 8 OPTION - PART NUMBER 01-P42311K001
5-3.1. GENERAL INFORMATION
This option allows 8.33 kHz tuning in t
he
VHF/UHF bands, and user selectable 8.33 kHz
receive channel spacing in the 117.9750 to 136.9750 MHz band.
It also allows the operator to
place the radio into Aviation mode, which restricts the operating
frequency range from 117.9750 to 136.9750 kHz, with tuning increments of 25 and 8.33 kHz.
Channel spacings of 25 or 8.33 kHz are assigned automatically by frequency, following the ICAO
standards for frequency entry.
This mode also restricts modulation to AM, and allows PT only, disabling the CT feature of
the radio.
5-3.2. ENABLING AVIATION MODE
To place the transceiver in the Aviation Mode, start with the
transceiver powered off and then press and hold the 4 [AV]
keypad while turning on the power. The unit will remain in
the aviation mode through subsequent power cycles until it
is returned to the normal operating mode.
The transceiver will set all the channel data for each
channel to a default value (118 MHz, PT, AM, 25 kHz
bandwidth, low power).
To return to the normal operating mode, start with the
transceiver powered off and press and hold the 6 [MODE]
key while turning on power.
The transceiver will reset all the channel data for each
channel to the default values (225 MHz, PT, AM, 25 kHz
bandwidth, low power).
.
5-3.3. TUNING AND CHANNEL SPACING IN AVIATION MODE
When in the Aviation Mode, the manner in which the frequency is entered and displayed
determines the actual operating frequency and the channel spacing. The
ICAO standard
mandates that specific channel spacings (either 25 or 8.33 kHz) shall be assigned to specific
frequency
entries. This also means the frequency that is entered and displayed may be different
from the actual frequency the transceiver is tuned to.
The Aviation Mode Frequency Chart below shows an example of how to enter frequencies
to select the desired operating frequency and channel spacing. 118 MHz is used in the table as
an example; however any frequency from 117.9750 to 136.9750 kHz may be selected.
For example, if the desired actual operating frequency is 118.000 MHz with a channel
spacing of 25 kHz, enter 118000 using the keypad or remote command. The result will be what is
shown in line 1 of the chart. If, however, the desired frequency is still 118.000 MHz but this time
with a channel spacing of 8.33kHz, enter 118005 and the result will be as shown in line 2 of the
chart. Note that the transceiver will display 118005 even though it is tuned to 118.000 MHz.
In some cases, only 8.33 kHz channel spacing is allowed. Examine lines 3 and 4 of the
chart. Because tuning increments of 8.33 kHz are allowed, the next possible operating frequency
after 118.000 MHz is 118.0083 MHz. In this case only 8.33 kHz channel spacing is available for