Highfields Amateur Radio Club
Technical Pages.

Vehicle specific radio fitting hints and tips:
Nissan Technical, General Information.
(Applies throughout the range).
This was taken from the Nissan Website Technical Section.
All I have done is reformat the text, add a few highlights
and put the content of 5 pages onto 1 page.

1. Mobile Radio Equipment Installation Guidelines.

• The information in this guideline is intended for use by those installing two-way radio equipment (transmitters and receivers) in vehicles. This guideline is intended for radio equipment marked with a CE symbol and which has the transmitting antenna installed on the outside of the vehicle.
• It has been prepared in accordance with current engineering principles and generally accepted practices, using the best information available at the time of publication.
• These guidelines are intended to supplement, but not be used in place of, detailed instructions for such installations which are the sole responsibility of the manufacturer of the land mobile radio.
• Since it is not possible to cover all possible installations of two-way radio equipment, Nissan cannot be held responsible for incidental or consequential damage arising from the use of the information contained herein.
• Certain land mobile radios or the way in which they are installed may affect vehicle operations such as engine performance and driver information, entertainment and electrical charging systems. Expenses incurred to protect the vehicle systems from any adverse effect of any such installation are not the responsibility of Nissan.
• Nissan vehicles are designed and tested for safe operation with correctly installed and used mobile and amateur radio communication equipment with up to 50 Watts of transmission power (see table 1 for power limitations with respect to frequency).
• Mobile radio equipment with greater than the maximum power for the respective frequency band (see table 1) may require special precautions beyond those outlined in this document.

Warning: Ensure that the maximum power for the respective frequency band outlined in table 1 is not considered a risk to vehicle occupants’ health with regard to electromagnetic fields generated in the vehicle. If this is considered a health risk it is advised to reduce transmitting power to an acceptable level.

• Nissan vehicles are designed with special consideration to the vehicle’s electronic systems to ensure there is no interference with listed radio frequency signals.
• To ensure compatibility with vehicle electronic systems, radio and telephone equipment must be installed properly by trained personnel in accordance with these general guidelines.
• Before using the vehicle all installations should be checked for evidence of interference between the newly installed communications equipment and the vehicle’s electronics.

2. Guidelines for installation.

Locating the Transceiver.

The transceiver location should be selected so that:

• It uses a solid mounting.
• It does not interfere with the vehicle operating controls.
• It is provided with sufficient ventilation.
• It does not obscure the driver’s view.
• Any illumination from the equipment does not cause reflection in the windows.

Warning

Do not mount any radio equipment in the deployment path of the airbag system.

Before using screws to mount the radio equipment, check the path of the screw will not damage vehicle wiring.

Connections to the radio equipment should be easily accessible so that the equipment may be removed for operation in transportable mode, or for repairs and servicing.

Routing the Wiring.

The cable should be as short as possible. Heavy-duty cable of a low electrical resistance should be used on long cable runs to minimize voltage drop.

The power connections must be made directly to the vehicle’s battery.

Avoid using the cigar lighter or “Power Point” outlets as power sources for radio communication equipment.

The connections should be fused as close to the battery as possible using a weatherproof fuse holder. Ensure the positive and negative power leads are twisted together to improve the radio equipments immunity to noise.

recommendation:

It is recommended that a fuse be placed in the transceiver negative lead to prevent possible transceiver damage should the battery to engine-block ground lead be disconnected inadvertently.

Avoid chafing or pinching of the wires during the routing of wires between the passenger and engine compartments. Use grommets over any exposed or sharp edges and seal all holes to ensure moisture resistance.

Route and secure all engine bay wiring away from mechanical hazards such as hot exhaust manifolds and all moving parts (Steering column, throttle linkage, fans etc).

Maintain as large a distance as possible between the power leads of the radio equipment and the vehicle’s electronic modules and wiring. Avoid looping wires and running power leads in parallel with the vehicle wiring over long distances.

Locating and Installing the Antenna.

The antennae for radio equipment should be mounted on the roof or at the rear area of the vehicle.

Nissan does not recommend using the bonnet to locate the antenna because the driver could be exposed to direct electromagnetic energy. The long term effects of this energy are currently unknown.

Diagram 1 shows suitable locations for mounting the antenna with regard to safe operation of the vehicle for the frequencies and power outlined in table 1.

Permanently installed antennae are preferable to magnetic, glass or body lip mounts for anything other than low power or temporary installations. Most of these alternative antennae can reflect significant power back towards the feed point; this reflected power could then radiate from the feeder cable inside the passenger compartment and be picked up by the vehicle wiring. However, a magnetic-mount antenna is a good tool for checking the proposed fixed antenna location for unwanted effects.

Glass mount antennae are only suitable for low power installations and consideration should be given to any special properties of the glass that may affect the antenna’s performance, such as coatings for privacy, solar gain and defrosting. Nissan does not recommend the use of glass mount antennae and favours permanent body mount antennae.

Warning: Do not mount glass mount antennae on glass that has integrated vehicle antennae for entertainment and driver convenience systems or integrated elements for heating.

Magnetic mount antennae should be mounted in a location that does not interfere with electrical solenoids or the vehicle compass, if fitted.

Nissan does not recommend the use of magnetic antennae and favours permanent body mount antennas.

It is important to ensure that the antenna is tuned correctly and the reflected power is kept to less than 10%

Recommendation:The radio installation should be checked regularly for proper SWR and any signs of damage or deterioration to ensure continuing compatibility with the vehicle.

The antenna location is a major factor in these effects.

Routing the Antenna Cable

The antenna cable should be of high quality, fully shielded coaxial cable (at least 95% shield coverage), and kept as short as possible whilst avoiding any looping. Ensure attention is given to the connector quality and termination techniques.

The antenna cable should be treated in the same way as the control and power ables. Avoid sharp edges, pinches, kinks and excessive tightening of cable ties. The cable should be no longer than is necessary and routed so as to avoid running in parallel with vehicle wiring over long distances. It should not contain any looping. If it is necessary to cross over wiring, cross perpendicularly.

3. Trouble Shooting

Should vehicle-radio interference develop following installation, the source of the problem should be identified prior to further operation of the vehicle. Most interference problems can be eliminated by following the guidelines below.

Possible causes and solutions of vehicle-radio interference include:

• Antenna location (move antenna to another position)
• Antenna feed line routing (locate as far as possible from vehicle electronics and wiring)
• Inadequate shielding or loose/corroded connectors on the antenna feeder cable
• Mismatched antenna or high SWR
• Power feeds not connected directly to the vehicle battery.
• Power feed routing (locate as far as possible from vehicle electronics and wiring).

Recommendation:

If vehicle-radio interference problems persist after following these guidelines, contact your radio equipment manufacturer for additional assistance.