8
check back at a later stage! One of the disadvantages of AM is the shorter range compared to FM or SSB and the
higher sensitivity of AM for ignition interference and board computers.
In
FM
the transmission power is always the same, even when speaking, hence hardly any interferences of other
devices are to be expected in this mode. Instead, when speaking the frequency of the device varies, hence it is
called frequency modulation. Due to expected interferences in AM and SSB modes some countries for a long time
permitted only FM. Advantage is the greater range compared to AM and the same volume of nearby and distant
stations as well as a clear modulation sound. Loud noise, which can be heard with weak or missing signals, is a
disadvantage. In FM mode it is virtually impossible to leave the squelch open.
SSB
(
S
ingle
S
ide
B
and) marks the highlight in the development of long-distance voice transmission. The
transmission mode SSB avoids the disadvantage of the low range of AM and focuses the entire transmission power
on a minimum frequency width, where during a speech pause the power is nearly shut down to zero. During
receiving a special circuit makes sure that the “side bands” and “carrier”, which were cut off during transmission,
are restored. This allows an enormous improvement in range compared to AM and FM. Not only the transmitter has
a greater range, but also the receiver has, due to the halved bandwidth, better sensitivity. The price for this is the
disadvantage that for receiving very accurate tuning is necessary, and that during transmission interferences of
neighboring devices is greater. Due to the necessary fine tuning of the receiver with the
Clarifier
(10), the use of
SSB while driving a vehicle is a problem and can – such as making a phone call – distract from the traffic. SSB is
rather an operating mode for base stations. This is the reason why SSB today is only used by skilled radio
operators – you virtually have to train and develop some intuition for the correct setting.
USB and LSB
In SSB mode a conventional channel is separated in two halves: the so-called
upper side band
(
U
pper
S
ide
B
and,
USB
) and the
lower side band
(
L
ower
S
ide
B
and,
LSB
). Both can be used independently. Example: you transmit
on channel 9 in USB. In reality, for speaking you only use the frequencies from 27.065 up to approx. 27.070MHz,
while in LSB you are using the frequencies below 27.065MHz to approx. 27.060MHz. Both side bands are mirrored;
hence transmitter and receiver must be set to the same side band. Otherwise you only receive gibberish.
Set Transmission Power (3)
Your device has a stepless control for transmission power. In normal mode the knob
PWR
(3) should be set all the
way to the right (clockwise). In this setting 4 Watts in FM (carrier power), max. 12 W SSB (PEP power) and 4 Watts
(carrier power RMS) in AM are achieved. Turn counter-clockwise to reduce power to approx. 100mW. This is
recommended if you only want to be heard in absolute close-up range.
Incidentally:
it also reduces the general electric smog level, when only as much transmission power is set as is
necessary for the radio contact!
How to Receive SSB?
As the receiver station you cannot know, with which side band your counter station is transmitting. The fact that the
counter station is transmitting in SSB is easily detected, since the “squawking noise” is very different from FM or
AM signals. Receive first in USB. Very carefully turn the
Clarifier
. If you can hear a “Mickey Mouse” voice, try to
carefully fine tune to a recognizable pitch. If this does not work, then try the other side band
LSB
.
You need some routine until you can clearly hear your dialog partner in SSB mode. But shortly you will be
rewarded with the first DX (= long-distance traffic) connections.
Use Frequency Memory (9)
Frequently used frequencies or channels can be saved and accessed via the
MSAVE/MLOAD button
(9) with the
respective mode in 5 station memories. The settings will not be lost during temporary power failure, since the
device works with flash backup memory.
Input Channel in Station Memories (1-5) (9)
•
Tune into the desired channel. Press
FUNC + M-SAVE + Station memory (1-5)
to save the frequency.
•
After
FUNC + M-SAVE
at first
ME
for “Memory” is shown on the display.
Access Frequency from Memory (9)
Press
M-LOAD
and the
Station memory
(
1-5
) to access the station memory (after entering
M-LOAD
the display
shows
ME
).
