Raymarine Ray48 manual Antenna Connections, Antenna Mounting Suggestions, Grounding

2.4.3 Antenna Connections

The coaxial cable to your VHF antenna is intended to be connected to the antenna jack on the rear panel using a PL259 VHF type connector. The antenna cable can be cut to length but the overall cable length can be critical to performance. If you are uncertain, contact a professional installer or call our Product Support department. If a longer cable length is required, RG-58 (50 ohm) coaxial cable or equivalent cable may be used for runs up to a maximum of 50 feet. If the distance required is even greater, then we recommend using low loss RG-213 or equivalent cable for the entire run in order to avoid excessive losses in power output.

If the antenna RF connector is likely to be exposed to the marine environment, a protective coating of grease (Dow Corning DC-4 or similar) can be applied to the connector before connecting it to the radio. Any other extensions or adapters in the cable run should also be protected by silicon grease and then wrapped with a waterproofing tape.

2.4.4 Antenna Mounting Suggestions

The best radio in the world is useless without a quality antenna and good location. Mounting the VHF antenna properly is very important because it will directly affect the performance of your VHF radio. A VHF antenna designed for marine vessels should be used.

•Since VHF transmissions are essentially line-of light, mount the antenna where it is free of obstructions to obtain maximum range.

•If you must extend the length of the coaxial cable between the antenna and the radio, use a coaxial cable designed for the least amount of power loss over the entire cable length.

•Keep the coaxial cable between the radio and antenna as short as possible but remember to maintain the recommended 3 feet between the radio and antenna.

Please note that some antennas are supplied with a cable that may not be altered in any way. Please check the instructions supplied with your antenna before cutting or altering the cable.

2.4.5 Grounding

While special grounding is not generally required for VHF radiotelephone installations, it is good marine practice to properly ground all electronic equipment to the ship's ground system. The Ray48 can be connected to ground by attaching a wire to one of the screws on the unit's rear panel and then to the nearest ship's ground connection point.

The recommended wire to be used for such grounding is #10 AWG.

Fig.2-6 TYPICAL GROUNDING METHODS

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