What is HF SSB?

Do you require Long Range Communications?

HF SSB is the answer

HF means High Frequency whereas SSB means Single Sideband

HF & SSB radios are capable of providing communication over hundreds to thousands of Kilometres.

Buy our high frequency Codan Products at Comm Spec

HF provides communication beyond the range that is possible with conventional VHF/UHF systems, which rely on the line-of sight between communicating parties. HF on the other hand, achieves long distance communication by bouncing its signal off the ionosphere (sky waves) as shown in the Diagram below. Until recently there had always been a dead space of roughly 70 -220 Km between the point where the ground wave terminated and the point where the first sky wave returned to earth.

Standard Base Station Antenna Propagation

This operational shortcoming is unacceptable and a solution has been found by using the NVIS System. Under this system, the antenna radiates a signal near vertically up to bounce down off the ionosphere, thus providing an uninterrupted footprint from ground "0" to a radius of 6,000 Km or more.

NVIS Base Station Antenna Propagation

This operational shortcoming is unacceptable and a solution has been found by using the NVIS System. Under this system, the antenna radiates a signal near vertically up to bounce down off the ionosphere, thus providing an uninterrupted footprint from ground "0" to a radius of 6,000 Km or more.

Two Way Radios and Cars

Mobile radios fitted in cars require little maintenance if the radio and antenna are permanently installed. However our engineers find that in lots of cases when the radio is fitted in hire cars the radio/antenna has to be easily removable. This results in the use of magnetic mounted antenna and the radio fitted under one of the front seats. Because the wiring is not fixed it is likely to get damage and become unreliable.

The two main areas that cause the most problems are that aerial cable and the microphone cable. Damage to the aerial cable will reduce the coverage area, put excessive strain on the electronics of the radio and area of radio coverage becomes unreliable. If the cable is not repaired or replaced expensive repairs to the mobile may be also required. Unfortunately as the aerial cable is coaxial it is not simply a case of a visual inspection but needs to tested with calibrated test equipment.

Damage to the microphone cable is also hard to detect as the cable is made up of very thin flexible wire, if it is damaged it will result is intermittent communication until it fails completely.

Some customers have obtained magnetic antennas that have a small magnetic base and very thin aerial cable (coax) believing that this will solve problems with the area of coverage - wrong! an antenna that is used for two way communication needs to be adjusted to operate on the required frequency efficiently.

The magnetic base is too small to keep the antenna on the roof of cars when passing under such things height restriction bars in car parks. Two-way radios and base stations should be checked at lest once a year to ensure that the equipment is operating within manufactures specifications and licensing requirements.