The Diamond NR77AM is a compact dual-band mobile antenna designed for vehicular installations operating across VHF (144MHz) and UHF (430MHz) frequency bands. Built with an optimized structural profile, this mobile transceiver element integrates a high-reliability electrical design that balances length and performance. The base section terminates in a standard MP (PL-259 compatible male profile) RF connector, facilitating clean mechanical matching onto standard heavy-duty mobile coaxial cable mounts.
The radiating element relies on distinct electrical wavelength configurations for each operating band to ensure efficient signal propagation. On the 144MHz VHF band, it functions as a 1/4 wave antenna layout. When operating on the 430MHz UHF band, it transitions to a 1/2 wave radialless design, providing a localized gain rating of 2.15dBi and allowing the antenna to maintain high radiation efficiency without requiring a direct grounding plane connection at that frequency. With a total power rating of 100W FM, it safely handles typical mobile transceiver outputs while maintaining a Voltage Standing Wave Ratio (VSWR) of less than 1.5:1 at resonance.
Features
- Dual-band integration optimized for concurrent 144MHz and 430MHz radio installations.
- 1/2 wave radialless configuration on UHF to minimize ground plane dependence.
- Compact structural length of 0.67m reduces risk of overhead obstruction contact.
- Standard MP base connector for secure matching onto mobile mounting hardware.
- Robust construction with a low-weight profile of 140g to limit mount stress.
Technical Specifications
| Parameter | Specification |
|---|---|
| Brand | Diamond Antenna |
| Model Designation | NR77AM |
| Operating Bands | VHF (144MHz) / UHF (430MHz) |
| System Gain (UHF) | 2.15dBi (430MHz) |
| Maximum Power Rating | 100W FM (Total) |
| Electrical Type (144MHz) | 1/4 wave |
| Electrical Type (430MHz) | 1/2 wave radialless |
| Nominal Impedance | 50Ω |
| VSWR Threshold | Less than 1.5:1 |
| Base Connector Type | MP (PL-259 profile) |
| Total Length | 0.67m |
| Net Weight | 140g |
Package Content
- 1x Diamond NR77AM Dual-Band Mobile Antenna Element
