Beams with variable length elements by Ultrabeam
Yagis are antennas, which element lengths are changed mechanically by a controller. This ensures that the antenna is always perfectly adjusted to the operating frequency. The design of the Yagi can be optimized to your location, taking height above ground and ground conductivity into regard. Did you ever try this with a conventional beam?
The Ultrabeam antennas are characterised by an extremely robust and carefully designed construction, mechanically and electrically. Here are some details of the individual components:
Ultrabeam takes special care of the mechanical quality and solidity. When we visited the manufacturing facilities in Italy for the first time we were very impressed by the care for details and the really solid construction. For example, the developer paid particular attention to the safe transport of the Copper-Beryllium (CuBe) tape inside the tubular elements. The simple solution would have been to use just a spring in the reel to pull back the CuBe band. But Ultrabeam uses a new system called 'VRS', Variable Reeling System where the reel is driven by the stepper motor, as well as using a spring to assure a good tension. The changing diameter of the tape on the reel is compensated for by a clever mechanic system. The CuBe tape is always safe on the reel.
The tubes, in which the CuBe tape moves, are made from light fibreglass and consist of three or four segments, depending on antenna model. These segments are assembled and fastened with heat shrink materials. Since May 2010 the fibreglass tubes are made from a special, nearly transparent and lighter material. This makes the antenna optically 'lighter' and less eye-catching, the material has a better UV resistance, and you can watch the CuBe tape move in the tubes. That makes diagnosing problems much easier.
All Ultrabeam directional antennas (except the Rotary Dipole and the 2-Element antenna) come with a large system to support the element tubes. This support plate holds the Element Housing Unit (EHU) plus has very solid aluminum blocks to support the tubes. With the large 21.5m long elements the support is even larger and has two clamps for each tube on either side. This makes sure that the EHUs are not subject to bending load.
The driven elements have two contacts with a surface om 10mm², providing reliable electrical contact of the feed line. This enables the Ultrabeam to handle a maximum power of 5kW PEP or 3KW CW key-down. The EHUs are made from ABS and coated with a special, UV and weather resistant varnish. Fed elements have a PL socket (female), each EHU has a water proof socket for the 4 conductor control cable (old system) or a 4 wire cable permanently attached (new system).
The boom of all Ultrabeam antennas is made from square tubes (6086 T6 aluminum). This assures that the elements are always installed absolutely horizontal on the boom. The 4-element antennas have a double boom for extra reinforcement, resulting in even lower torsion at little additional weight. Each element and the boom are colour coded, preventing any misunderstanding when assembling the antenna. The mast plate, fixing the boom to the mast is cut from stainless steel and very solid (the plate for the 4-element antennas uses 6 mm strong material!). The boom of the 4-element antennas uses additional trusses above the boom for added rigidity. The required installation material and nylon rope is included. All mounting hardware is made from aluminum or stainless steel (except boom reinforments), with metric screw threads.
Ultrabeam Control Cable for Antennas
Each motor unit (EHU, Element Housing Unit) requires a 4 or 6 wire cable. 4 wires are used by the stepper motor, and in some cases two additional wires are required for a relay. This relay switches the balun configuration between 25 and 50 Ω. This is required for some antenna designs, switching is done automatically. Some antenna models require two further wires for the transfer relay which selects the radiating element. This transfer is required for some models for the rapid 180° direction exchange, or when changing the configuration per band. Again, this switching is handled automatically by the controller.
WiMo supplies each Ultrabeam antenna with a ready-to-use cable with connectors attached. The price of the antenna always includes a 30m long cable, otehr cable lengths are available on request. To order a different cable length (only longer cables possible) just order the number of meters required in addition to the 30m cable. The suitable cable type is mentioned below each antenna. The supplied cable is fitted with connectors which must be connected to the EHUs and the controller. This prevents any misunderstandings when assembling a 'do it yourself' cable. The disadvantage of this system is that you have to make a larger hole in the wall to feed the cable through. If required you can cut the cable at a suitable place, feed it through a small (10 to 12mm) hole and reconnect it afterwards with the help of screw joints.
Ultrabeam antennas offer the following special features:
- • The antennas have a square boom. This fixes the elements always horizontally on the boom, even after a storm.
- • The newly developed VRS Variable Reeling System makes sure that the retracting force for the CuBe tape is always constant, independent of of the position of the elements.
- • All mounting hardware (except boom reinforcements) are made from stainless steel or aluminum and have metric sizes.
- • The controller have discrete transistor drivers for the stepper motors. These drivers can handle up to 10A current and are short-circuit proof and protected against errors in wiring.
- • Software updates for the controller are available free of cost via Internet.
- • The controller has a large colour LC display (touch screen) with menu oriented use. A serial CAT interface is installed with every controller.
- • The control wires are connected with water protected connectors to the EHUs. No more simple terminal strips.
- • Ready-made control cables are available as an option (state required length, 30m is standard). Just plug the cable into the motor units and into the controller - and go!
- • Direct interface with many microHAM devices: microKEYER-II, MK2R/MK2R+ and Station Master. See below for details.
The control unit RCU-06
Each Ultrabeam antenna is supplied with the convenient RCU-06 control unit, which is used to operate the antenna. A large, colour touch display serves as input for all settings. During normal operation, the respective band is selected here and the antenna can then be adjusted in fixed scrits. It becomes even more comfortable if you connect the controller to the CAT interface of the transceiver. So the antenna can always follow the set frequency. In order to be able to integrate existing devices such as a power amplifier, the controller has a CAT output on which the transceiver's data can be passed on.
A software is available for the computer, which can also control the antennas via the USB interface of the controller. So you are not only dependent on the controller for control. This is especially important for remote controlled stations. With the PC software you can also make various settings, e.g. adapt the antenna modelling to the local conditions. For example, the influence of the ground (height above ground, ground conductivity) can be stored in a separate antenna model, and you can achieve a higher efficiency of the antenna.
The RCU-06 controller is also available separately, for example to retrofit older antenna systems. Please note that the pin assignment of the control cable between old controller and RCU-06 is different! If required we can offer suitable adapters. Suitable for the controller and transceiver we offer some CAT cables.
Ultrabeam and microHAM interfaces
The cooperation between Ultrabeam and microHAM ensures that the microHAM interfaces micro KEYER II, MK2R/MK2R+ and Station Master can directly control the antennas. This has the following advantages:
Ultrabeam - Data transmission protocol
We document the procedure for transferring commands and data at this point in the hope that program authors will be able to use this information and incorporate the controller into their programs. Please do not hesitate to contact us if you have any questions. The description is only available in English.