Diamond Car and Truck Mobile UHF Antenna

Diamond UHF mobile antenna – main technical characteristics

The Diamond antenna uses a vertical radiator with a 5/8-wave electrical design. The frequency-adjustable configuration is accompanied by a manufacturer's cutting chart. Its documented VSWR is below 1.5:1 when properly adjusted. The antenna requires a separate mounting base, so the mounting arrangement and coaxial cabling must be selected according to the vehicle's specifications.

Diamond UHF mobile antenna technical specifications

• Frequency range: 340-520 MHz.
• Antenna design: 5/8 Lambda.
• Antenna gain: 3.4 dB.
• Maximum input power: 250 W in FM mode.
• Impedance: 50 ohms.
• VSWR: below 1.5:1.
• Antenna length: 57 cm.
• Weight: 170 g.
• Connector: PL male.

These specifications describe the antenna when adjusted to the appropriate frequency. The 340-520 MHz range does not mean that identical impedance matching is achieved at every frequency without adjustment.

What frequency range does the Diamond UHF mobile antenna support?

The UHF mobile antenna can be adjusted for frequencies between 340 and 520 MHz. This allows the length of the radiating element to be matched to the selected operating frequency. Adjustment is performed according to the manufacturer's cutting chart, after which impedance matching must be verified through VSWR measurement. The radio equipment must also support the intended frequency range and comply with the applicable operating requirements.

5/8 Lambda antenna design for UHF radio communication

The electrical length of a 5/8 Lambda antenna is related to the wavelength of its operating frequency. Vertical radiators of this type have a radiation distribution that differs from conventional quarter-wave antennas. However, actual performance also depends on the installation environment and antenna system matching. The antenna should therefore be checked and adjusted in its final mounting position on the vehicle.

What does 3.4 dB antenna gain mean?

The documented antenna gain is 3.4 dB. This value describes the antenna's radiation characteristics and does not indicate active signal amplification. Actual radio communication performance depends on several factors, including transmitter power, antenna position, coaxial cable losses, and surrounding obstacles. Impedance matching and secure antenna mounting must therefore be considered alongside gain.

430 MHz antennas and the 70-centimetre amateur radio band

A 430 MHz antenna can be used on suitable frequencies within the 70-centimetre amateur radio band when correctly adjusted. The 340-520 MHz range includes these frequencies, but frequency-specific adjustment remains necessary. When selecting an amateur radio antenna, the radio's transmit power, PL connector compatibility, and intended operating frequency must all be checked.

What transmit power does the Diamond mobile antenna support?

The Diamond vehicle radio antenna has a maximum power-handling capacity of 250 W in FM mode. This specifies the upper limit of permitted RF input power, not power generated by the antenna. The connected transmitter must not exceed the documented rating. When designing the complete antenna system, the power-handling capabilities of the coaxial cable and connectors must also be verified.

50-ohm antenna impedance, VSWR, and frequency-specific adjustment

The antenna impedance is 50 ohms, and the documented VSWR is below 1.5:1 when properly adjusted. Voltage Standing Wave Ratio describes the impedance matching between the antenna and transmission line. Shortening the radiating element is a permanent modification, so the manufacturer's cutting chart must be followed accurately. We recommend checking the VSWR with a suitable UHF measuring instrument after adjusting the antenna.

What PL connector and coaxial cable are required?

The antenna features a PL male connector, also known as a PL-259 connector. A compatible antenna mount with the corresponding female connector is required. A 50-ohm coaxial cable should be used between the radio and antenna mount. Cable length, frequency-dependent attenuation, and connector compatibility must all be considered when selecting the cable.

Antenna mounting, mechanical dimensions, and vehicle installation

When planning antenna mounting, the antenna's 57 cm length and 170 g weight must be considered. A compatible PL female antenna mount can be selected from magnetic, through-hole, or bracket-mounted solutions, provided that the accessories are mechanically suitable. The coaxial cable must be routed so that it does not interfere with the vehicle's controls, and the antenna must remain securely mounted.

How should you select the right Diamond UHF mobile antenna?

Begin by determining the radio's operating frequency. Next, verify the 250 W FM power limit, 50-ohm impedance, and PL connector compatibility. Then select a suitable antenna mount and coaxial cable for the vehicle. After installation, the antenna's frequency-specific adjustment and VSWR must also be checked.

FAQ – Diamond UHF mobile antennas

• What frequency range does the antenna support?
  It can be adjusted to the required operating frequency between 340 and 520 MHz.
• What is the antenna gain?
  The documented gain is 3.4 dB.
• What is the maximum power rating?
  The antenna supports a maximum input power of 250 W in FM mode.
• How long is the antenna, and how much does it weigh?
  The antenna is 57 cm long and weighs 170 g.
• Which connector does the antenna use?
  It features a PL male connector and requires a compatible antenna mount with a PL female connector.
• Is frequency-specific adjustment required?
  Yes. The radiating element must be adjusted to the intended operating frequency using the manufacturer's cutting chart.
• What is the antenna impedance?
  The impedance is 50 ohms, with a documented VSWR below 1.5:1 when properly adjusted.

Summary

The Diamond UHF mobile antenna is a frequency-adjustable 5/8 Lambda mobile antenna designed for operation between 340 and 520 MHz. Its main technical characteristics include 3.4 dB gain, a maximum FM power rating of 250 W, 50-ohm impedance, and a PL male connector. We recommend checking the radio's operating frequency, connector compatibility, antenna mount, and frequency-adjustment requirements together before purchasing.