VHF Antenna Installation Antenna Location, Cabling

MX535 UAIS Transponder Unit

Technical & Installation Manual

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3.5 Installation of VHF / GPS Antennas

Interference to the Ship’s VHF Radiotelephone

The AIS ship borne equipment, like any other ship borne transceiver operating in the VHF maritime band, may cause interference to a ship’s VHF radiotelephone. Because AIS is a digital system, this interference may occur as a periodic (e.g. every 20 seconds) soft clicking sound on the ship’s radiotelephone. This may become more noticeable if the VHF radiotelephone antenna is located close to the AIS VHF antenna, and when the radiotelephone is operating on channels near the AIS operating channels (e.g. channels 27, 28 and 86).

Attention should be paid to the location and installation of the various antennas, in order to support the antenna characteristics in the best possible way.

3.5.1VHF Antenna Installation

Antenna Location

Location of the mandatory AIS VHF-antenna should be carefully considered. Digital communication is more sensitive than analogue/voice communication to interference created by reflections caused by obstructions such as masts and booms. It may be necessary to relocate the VHF radiotelephone antenna to minimize interference effects.

To minimise interference effects, the following guidelines apply:

The AIS VHF antenna should have omni directional vertical polarisation providing 3 to 5 dB gain.

The AIS VHF antenna should be placed in an elevated position, as free standing as possible, with a minimum of 2 metres in horizontal direction from constructions made of conductive materials. The antenna should not be installed close to any large vertical obstruction. The AIS VHF antenna should have a visible sky of 360°. The AIS VHF antenna should be installed at least 3 meters away from interfering high-power energy sources such as radar and other transmitting radio antennas, and out of the way of the transmitting beam.

There should not be more than one antenna on each level. The AIS VHF antenna should be mounted directly above or below the ship’s primary VHF radiotelephone antenna, with no horizontal separation and a minimum of 2 metres vertical separation. If it is located on the same level as other antennas, the distance apart should measure at least 10 metres.

Cabling

The cable should be kept as short as possible to minimise attenuation of the signal. Double shielded coaxial cables equal to or better than RG214 are recommended.

RG214 at VHF attenuation per meter of app. 0.07 dB/m (45m = 3.15db) VHF AIS frequency app. 162MHz

All outdoor connectors on the coaxial cables should be fitted with preventive isolation, such as shrink-stocking with silicone to protect the antenna cable against water penetration. Coaxial cables should be installed in separate signal cable channels/tubes, and at least 10 cm away from any power supply cables. Crossing of cables should take place at right angles (90°). Coaxial cables should not be exposed to sharp bends, which may lead to changes to the characteristic impedance of the cable. The minimum bend radius should be 5 times the cables outside diameter.

Grounding

Coaxial down-leads must be used for all receiving antennas, and the coaxial screen should be connected to the ground at one end.

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MX535 specifications

The Leica MX535 is a compact and sophisticated point-and-shoot camera designed for photography enthusiasts who appreciate both portability and high-quality imaging capabilities. Known for its exceptional optical performance and robust build quality, the MX535 offers a unique blend of classic Leica aesthetics with modern technological advancements.

One of the standout features of the Leica MX535 is its 24-megapixel CMOS sensor, which delivers stunning image quality with high resolution and impressive detail. Coupled with the Leica Maestro image processor, it ensures fast processing speeds and excellent noise control even at higher ISO settings. Photographers can expect vibrant colors and dynamic range, making the MX535 ideal for various shooting conditions.

The camera is equipped with an integrated optical viewfinder, providing a clear and bright view of the scene. This feature is particularly favored by photographers who enjoy composing their shots visually rather than relying solely on electronic displays. The 3-inch LCD screen on the back provides intuitive access to settings and playback, making it easier to review images in bright sunlight.

A significant technological advancement in the Leica MX535 is its autofocus system, which employs contrast detection and offers multiple focus points for greater precision. This system allows for quick focus adjustments and ensures that subjects remain sharp even in challenging lighting situations. Additionally, the camera features different shooting modes, including manual focus, giving photographers the flexibility to achieve their desired creative vision.

The MX535’s construction is robust, featuring a magnesium alloy body that not only enhances durability but also provides a comfortable grip. Its weather-sealed design makes it suitable for outdoor photography and protects it against dust and moisture, providing versatility for photographers who enjoy various environments.

Another key characteristic of the Leica MX535 is its compact design, making it easy to carry anywhere without compromising on quality. With its sleek lines and classic design elements, it attracts attention while embodying the timeless heritage of Leica cameras. The camera also supports full HD video recording, allowing users to capture motion alongside still images with stunning clarity.

In conclusion, the Leica MX535 stands out as a premium compact camera that combines exceptional image quality, advanced technology, and an elegantly durable design. With its impressive features, it caters to both amateur and experienced photographers who seek a reliable and stylish camera for everyday use or special events.