8
•
You can tune the frequency via the
CHANNEL
knob (9) on the unit or with the UP/Down buttons on the
microphone.
•
Press
FUNC
followed by
2
to toggle between the display modes.
Frequency Steps (channel knob)
Per default the frequency steps are 10 kHz. You can change the step width by key
STEP (5)
to 1, 10 or 100 kHz
steps. After 1 x pressing
STEP
you will see the cursor appearing below the corresponding digit of the frequency
readout, depending how often you press the button. Now you can select the digit of Your choice with the channel
knob or up/down. Pressing
FUNC (12)
will switch back to 10 kHz default step system. The 10 kHz steps now will
start from the before shifted frequency!
Example:
You have used
STEP
and the channel switch and reached 29.138 MHz.
Now you press
FUNC
and use
the
channel switch
again. Your next frequency will be
29.148 MHz, 27.158 MHz and so on.
Buttons AE 485 S (5-12)
The buttons of your unit are multi-functional and change automatically – according to the mode – or in combination
with the
FUNC
button
(12)
manually. To avoid confusion you will find only the name of the corresponding function
in this user manual. For instance for pressing the
MODE
button you will find “
MODE
” and not the all names of all
functions for this button, such as
“
MODE/LOW/5
”. Furthermore, all button functions, which are only possible in
connection with the
FUNC
button, are printed in blue.
Select Mode
Press the
MODE
button (8) to toggle between AM, FM, USB and LSB. The selected mode is displayed. The
abbreviations stand for:
AM
Amplitude modulation A3 with full carrier
FM
Narrow band
frequency modulation (max. 2.0 kHz range)
USB
Single-sideband modulation, upper side band
LSB
Single-sideband modulation, lower side band
The different modes for Amateur radios are partly historical, as Amateur radio started with AM more than 50 years
ago.
AM (amplitude modulation)
mode corresponds with the technical operation of medium wave and short wave
broadcast und is, except for CB radio, currently used for aircraft radio. While speaking the transmission power is
adjusted rhythmically (technical term “modulated”). AM is traditionally the radio system used by truck drivers
worldwide for CB radio. The low background noise is advantageous if for instance in low interfering diesel trucks
squelch is left open during standby operation. A disadvantage is the lower communication range compared to FM
(because of higher allowed power in FM) or even SSB and the varying volume between near and far stations.
In
FM
mode the transmission power is always the same when speaking, thus hardly any interferences from other
units are to be expected in this mode. Instead the frequency of the unit varies during speaking and for this reason it
is called frequency modulation. Advantage is a greater range compared to AM and a constant volume of near and
far stations as well as a clear modulation sound. Some noise is a disadvantage and can be heard with weak or
missing signals. In FM mode it is basically not possible to leave squelch open in standby operation. FM is used on
the 10 m Band only for operation via repeaters.
SSB
(
S
ingle-
S
ide
B
and) marks the height in the development in long distance traffic voice transmission. SSB mode
avoids the disadvantage of low range of AM and concentrates all transmission power on a minimum frequency
width with speech pauses reducing the output to nearly zero. For reception a special circuit ensures that the
transmission of cut off “sidebands” and the “carrier” are again restored. This achieves an enormous increase in
range compared to AM and FM. Not only does the transmitter reach further, also the receiver is substantially more
sensitive through the halved bandwidth. All this has to be paid for with the disadvantage of a very fine tuning being
necessary for reception and that there is a higher risk of interferences of nearby devices during transmission. Due
to the necessary fine tuning of the receiver with the “
Clarifier
” (11) the use of SSB in moving vehicles is a problem
and can distract in an objectionable way from the traffic, similar to using a mobile phone. SSB is rather a mode for
base stations. This is also the reason, why today only experienced radio operators use SSB – you really have to
train and develop a sure instinct for the correct setting.
USB and LSB
In SSB mode a conventional channel is divided in two halves: the so-called
upper sideband
(
USB
) and the
lower
sideband
(
LSB
). Both can be used independently. Example: you transmit 28.500 MHz in USB. In reality you use
