Receiving Ssb Signals - Yeti Communications Huracan HR-07-NZ Owner's Manual

Receiving SSB Signals

There are four types of signals presently used for communications in an Amateur band: AM, FM,
USB and LSB. When the MODE switch on your unit is placed in the AM position, only standard
double sideband and in FM position, only frequency deviation, full carrier signals will be detected.
An SSB signal may be recognized while in the AM or FM mode by its characteristic " Donald Duck
" sound and the inability of the AM or FM detector to produce an intelligible output, the USB and
LSB modes will detect upper sideband and lower sideband respectively , and standard AM signals
SSB reception differs from standard AM reception in that SSB receiver does not require a carrier
or opposite sideband to produce an intelligible signal. A signal-sideband transmitted signal
consists only of the upper or the lower sideband and no carrier is transmitted. The elimination of
the carrier from the AM signal helps to eliminate the biggest cause of whistles and tones heard on
channels which make even moderately strong AM signals unreadable.The reduction in channel
space required also helps in the receiver because only half of the noise and interference can be
received with 100% of the SSB signal.
An SSB signal may be received only when the listening receiver is functioning in the same mode.
In other words, an upper sideband signal (USB) may be made intelligible only if the receiver is
functioning in the USB position. If the lower sideband (LSB) signal is heard when the receiver is in
the USB mode, no amount of tuning will make the signal intelligible.
The reason for this may be understood if you consider that when modulation is applied to the
transmitter's microphone in the USB mode, the transmitter's output frequency is increased
whereas in the LSB mode the transmitter's output frequency is decreased. The result in listening
the receiver is that when the MODE switch is in the proper position either USB or LSB.
A true reproduction of signal tone of modulation will result, and if the tone is increased in
frequency such as a low pitched whistle will caused a high-pitched whistle you will hear the
increase in the output tone of the receiver. If the incorrect mode is selected, an increase in tone of
a whistle applied to the transmitter will cause a decrease in the resultant tone from the receiver.
Thus when a voice is used in place of a whistle or tone, in the proper listening mode the voice will
be received correctly whereas in the incorrect mode, the voice will be translated backwards and
cannot be made intelligible by the voice lock control. When listening to an AM transmission, a
correct sideband is heard in either mode since both upper and lower sideband is received.
Once the desired SSB mode has been selected, frequency adjustment may be necessary in order
to make the incoming signal intelligible, the CLARIFIER control allows the operator to vary
frequency above and below the exact-center frequency of the received signal. If the sound of the
incoming signal is high or low pitched, adjust the operation of the CLARIFIER. Consider it as
performing the same function as a phonograph speed control. When the speed is set to high,
voices will be high-pitched and if set too low, voices will be low-pitched. Also, there is only one
correct speed that will make a particular record produce the same sound that was recorded. If the
record is played on a turntable that rotated in the wrong direction (opposite sideband) no amount
of speed control (CLARIFIER) will produce an intelligible sound.
An AM signal received while listening in one of the SSB modes will produce a steady tone (carrier)
in addition to the intelligence, unless the SSB receiver tuned to exactly the same frequency by the
Clarifier control. For simplicity it is recommended that the AM modes be used to listen to AM
signals.