What is A Single Sideband and How It Is Different From HF

When starting in front of a radio for the first time, a technician might be more comfortable with the VHF and UHF operations that are used for telephones. These phone frequencies use simplex FM channels along with the corresponding repeaters. The FM frequency used in UHF and VHF operations is very easy for anyone to get their first ever Technician Class License. After gaining some experience as a technician, individuals might want to advance their skill on the radio and move toward single sideband operations used in the phone. Radio contacts are more advanced and have a broad range when the Single sideband operations are used. These are the operations that allow for international and all long-distance communication opportunities. In general, these operations are perfect for distance communications unlike the distance covered by an FM frequency. When starting with a single sideband operation, you will be able to get the phone frequency for 10 meters even with the Technician Class licence. Accessing longer distances means that you have to skip over the horizon when propagating through the ionosphere.

The Technicalities Behind SSB

Simply put, the SSB is a form of AM frequency. They are known to consume lesser bandwidth than the standard AM signal. When you take a closer look at the AM frequency, you will realise that they are 6kHz wider and have two bands. Each of these bands is found on either side of the primary frequency. They are also a mirror of each other. The two sidebands carry the voice signals on either side of the main AM signal. The speciality of the AM wave is that it can transmit high quality of sound and covers a broadband spectrum.

Now, the most significant thing about the Single Sideband is that it uses only one of the sidebands of the AM signal. Therefore, the signal is only half of the AM band. Having to use only one of the two sidebands means that these things can occur:

  1. The signal that is transmitted because of the Single Sideband ensures that very little of the available spectrum is utilised. Using one band only allows for more signals to pass through the same frequency without any disruption.
  2. Due to the narrow nature of the sideband, the signals are robust and denser. Theresuting effect is a powerful punch to the information transmitted than what can be achieved through the AM or FM frequency as a whole. The entire AM or FM frequency is broad which means that more information and power has to be fed into the signal which is only a waste of spectrum, which is why amateurs prefer the single sideband frequency.

It can be a worry for amateurs to choose between the two available bands. Therefore, a simple rule of thumb is followed without getting into too many technicalities. The higher sideband is used when the signal transmission is over 30 meters. If the transmission is lesser than 30 meters, then the lower band is used. In most cases, higher sideband is used. The lower sideband allows only five USB channels.


Comments are closed.