Firestik Antenna Company 2M-4 5/8 Wave 2M Mobile Antennas

Firestik Antenna Company 2M-4 5/8 Wave 2M Mobile Antennas are an omni-directional antenna designed for the 144 to 148 MHz, 2-meter amateur band. They offer the lowest angle of radiation of any mobile VHF antenna, making them a well-kept secret among knowledgeable users. These 5/8 wave (both physical and electrical) antennas have a nominal impedance of 50-52 ohms and can achieve an average tuned SWR of 1.5:1 over 4 MHz. The overall length is 48.2 inches (122.4 cm) and provide a gain of 6 dB over isotropic antenna and 3 dB over a 1/4 wave antenna. These 2M mobile antennas are rated at 400 watts AM and 800 PEP

In addition to their wide bandwidth and low angle of radiation, these antennas are resistant to static noise and can be tuned to higher frequencies. Test bench results show that the frequency increases by 300 KHz for every 0.125 inches of fiberglass/wire removed from the antenna.

Their core is made of 3/8 in. (0.375 in. or 10 mm) solid fiberglass, using a special Firestik formula for a balance of ruggedness and flexibility. The conductor consists of double-insulated 19-gauge copper wire. The covering is high-quality PVC with added UV and pigment stabilizers. The antenna base is chrome-plated machined brass with standard 3/8-24 in. threads, ensuring full compatibility with all wide range of mounts and accessories.

These are ground-plane dependent antennas, requiring a metallic counterpoise to perform properly. They are not suitable for use on non-metallic (composite) vehicles or those with insufficient metal. However, they can be used to build a base station antenna if a ground-plane is provided. When used with a transmitter (as opposed to a receiver), these antennas should be tested and tuned across the transceivers operating frequency. Using an untested, untuned antenna for transmitting can damage the transmitter's circuitry.

Important: Ground-plane dependent antennas require mounting brackets and antenna stud mounts that are grounded to a chassis ground point. Powder coating, paint, and/or anodized surfaces are insulating coatings and must be removed down to the metal surface wherever a grounding point is required.

Specifications:

• Frequency Range: 144 - 148 MHz

• Power Rating: 400 watts AM, 800 PEP

• Wavelength: 5/8

• Gain: 6 dBi

• Height: 48.2 in.

• 3/8-24 in. Threaded Base