SHF is Full of New Discoveries and Challenges!
Unique Propagation and High-speed Video Communication
SHF bands cover frequencies from 3 GHz to 30 GHz. SHF radio waves have high directivity, making them widely used in various wireless systems such as satellite communications, TV broadcast relay links, wireless LANs, and radar sensor networks. However, these professional wireless systems operate under the assumption that "SHF radio waves travel in straight lines."
Amateur radio in the SHF bands, on the other hand, utilizes not only direct propagation but also various propagation modes, including mountain diffraction (knife-edge diffraction), rain scatter, and reflections for communication. This creates a continuous series of surprises, and makes SHF an attractive band full of new discoveries and challenges. Furthermore, SHF bands have wide frequency allocations, allowing operators to enjoy various types of communication including TV video and high-speed, high-capacity data.
Industry First Multi-Band 144 MHz to Microwave Transceiver!
|905
- Adopts a separated configuration with controller and RF unit for direct antenna mounting
- Power is supplied to the RF unit through a controller cable
- Optional CX-10G 10 GHz transverter
- Achieves high-accuracy frequency stability by using GPS (GNSS) signals
- Real-time spectrum scope covering a wide bandwidth of up to 50 MHz
- Supports FM-mode ATV
Discover New Frontiers in SHF Communication!
In bands above 1200 MHz, you can enjoy unique communications, such as ATV (Amateur Television), high-speed data, and beacons, not available in other bands. Furthermore, since the SHF band has very wide bandwidth, you can easily enjoy various types of communication.
Experience Unique Propagation
While SHF bands are often thought to only allow direct wave communication, you can also utilize reflected waves, diffracted waves, rain scatter, and radio ducting. These propagation modes are actively utilized in the amateur radio world to communicate with stations beyond line-of-sight and distant locations.
Direct Wave
SHF band direct waves can reach any location within the line-of-sight range.
Propagation loss < Antenna gain + Output Power
Line-of-sight propagation distance:
Examples:
Elevation = 1000 m (3281 ft)→ Distance = 133 km (82.6 mi)
Elevation = 2000 m (6561 ft) → Distance = 187 km (116.2 mi)
Rain Scatter
High frequencies are attenuated by rainfall—the stronger the rainfall, the greater the signal loss. However, in amateur radio, you can also take advantage of reflections from raindrops to make contacts.
Diffraction/Reflection
When highly directional radio waves pass through mountainous terrain, they may diffract around sharp peaks—a phenomenon known as knife-edge diffraction. Radio waves can also reflect off mountains and tall buildings. These mountain reflections vary, depending on factors such as snow cover and surface moisture, which affect propagation distance. This unpredictable propagation makes SHF band operation exciting.
Radio Ducting
Radio ducting occurs when specific atmospheric conditions—such as temperature, pressure, and humidity—form a propagation path that behaves like a waveguide for radio waves. A temperature inversion layer, formed between a warm, dry air mass above and a cooler, moist layer below, can trap and guide radio waves by bending or reflecting them within the layer. As the radio waves bounce between the inversion layer and the ground or sea surface, they can travel over much greater distances than under normal conditions.
Amateur radio operators actively try to use radio ducting to communicate with distant stations, though it can sometimes interfere with commercial radio services.
Building Antennas and Accessories
Since SHF bands have very short wavelengths, antennas are easier to build yourself compared to other bands. In fact, there are enthusiasts who make antennas or build accessories such as transverters using inexpensive tools available at home improvement stores (DIY stores).
Output Power is the Same for Everyone
In the HF bands, the output power you can be licensed for varies, depending on your license class. However, in the SHF bands, the output power is the same, regardless of license class. One of the attractions is that beginners and advanced operators alike can enjoy operating under the same conditions (output power).
Please refer to the Amateur Radio regulations in your country for SHF band operation.
IC-905 Makes SHF Operation Easy - Even for Beginners!
Easy Setup! Beginner-friendly
Easy configuration with clear MENU screens & touch operation!
Features graphical, easy-to-understand MENU displays and an excellent touch panel interface. Even beginners can easily configure settings and enjoy SHF bands in all modes.
Easy Amateur TV Communication
Simply connect an analog camera for easy video communication!
With FM-mode ATV support, you can enjoy video transmission and reception using just the IC-905 by connecting an analog camera. Enlarged video display is also possible.
ATV Video Reception Example
Enlarged Video Display Example
On-Air Stations Are Clearly Visible
Finding Contacts with the Spectrum Scope
The IC-905's real-time spectrum scope covers up to 50 MHz of wide bandwidth. Even across the wide SHF bands, you can visually identify on-air stations. On-air stations are clearly visible at a glance. You will not miss any signals.
Basic Knowledge You Need to Know
Antennas
SHF band waves are highly directional and maintain their polarization, making it important to check polarization compatibility with the other station, before trying to make contact. Up to 1200 MHz and 2400 MHz, Yagi antennas and multi-element loop antennas are commonly used. From 5.7 GHz and above, horn antennas and parabolic dish antennas become standard. Some sources also publish antenna templates for DIY antennas, so try searching the Internet.
Coaxial Cable
SHF band coaxial cables need to be kept as short as possible to minimize loss. Additionally, even with the same internal structure, cables can have different names and flexibility, depending on their outer jacket. Since characteristics are determined by the cable's internal structure, it is difficult to judge by appearance alone. It is best to consult with a reliable shop for purchase, or look for cables at microwave flea markets and amateur radio event vendor areas.
Finding Contacts
One method is to use beacon stations to check propagation conditions and adjust antenna direction to locate stations for contact. You can also participate in local microwave roll calls or join "Field Day", where microwave enthusiasts from across the country go on-air simultaneously.