RadioRanked verdict
Comet
Comet CA-2X4SRNMO Dual-Band Mobile
The length genuinely buys performance here, particularly on 70cm, but you are trading a lot of convenience and money for it. Fine for a fixed vehicle you are not squeezing into tight spaces.
Proprietary RR score
How we scored it
Performance is derived from the antenna's length in wavelengths on each band it covers, not from the advertised gain. How we score →
Length versus wavelength
What 1016 mm Buys You
An antenna radiates according to its length measured in wavelengths, not according to the number on the packaging. Here is where this one lands on each band it covers.
| Band | Wavelength | This antenna | Works out as |
|---|---|---|---|
| VHF146 MHz | 2053 mm | 0.49 λ | half wave |
| UHF435 MHz | 689 mm | 1.47 λ | multi-wavelength |
Decision helper
Is this antenna right for you?
Yes, if you're…
- ✓Fixed installs where reach matters more than looks
- ✓Operators who want a longer, higher-performing NMO whip and can live with the size
Skip it, if you're…
- ✕Low-clearance parking (garages, drive-throughs)
- ✕Budget builds (the shorter Comet SS-460 costs less than half as much)
Tradeoffs
The good and the bad
What we like
- Genuine multi-wavelength length on 70cm, not just a marketing label
- Established Comet build quality, 4.6 stars
- Wideband coverage beyond the ham allocations
What we don't
- 40 inches is unwieldy for daily driving and low clearances
- $90 is a lot for an antenna with no printed gain figure to hold it to
- NMO mount and coax sold separately
Ready to buy?
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Overview
The Comet CA-2X4SRNMO is a 40-inch (1016 mm) dual-band NMO whip built for wideband VHF/UHF coverage beyond the ham bands. Comet does not publish a specific gain figure, but the length tells the story: on 2 meters it sits right at half wave, and on 70 centimeters it stretches to 1.47 wavelengths, well into multi-wavelength territory where a well-designed element genuinely gains over a simple quarter wave.
Our model puts that at roughly 3.5 dBi on 2m and 5.4 dBi on 70cm, a real step up from a basic whip, which is what "high-gain" should mean on an antenna this long. The cost is size and price: 40 inches is a lot of whip to live with day to day, and at $90 you are paying for that length. It needs an NMO mount and coax, neither included.
Specifications
| Frequency bands | VHF, UHF |
| Connector | NMO |
| Length | 1016 mm |
| Antenna type | mobile |
| Flexible | No |
| color | Black |
| unitCount | 0 |
Key Features
- Wideband dual band performance enables operation across the full 2M and 70cm amateur bands with extended coverage for VHF and UHF public safety, commercial, and scanner use Designed for users who need more than standard ham band operation, the CA-2X4SRNMO covers a broad frequency range with optimized tuning to support amateur radio, commercial frequencies, and general scanning applications.
- High-gain mobile antenna design provides strong transmit and receive performance for communication in urban, rural, and obstructed areas Its efficient radiating structure enhances both outbound and inbound signal strength, making it ideal for mobile operators who require reliable communication over varying terrain or long-distance repeater paths.
- NMO connector base ensures compatibility with the most widely used mobile mounting systems, allowing easy integration with magnet mounts, trunk mounts, fender mounts, and permanent NMO installations The universal NMO standard provides a secure, weather-resistant connection and makes upgrading from other NMO antennas simple without needing to replace the mount.
- Flexible and durable whip construction resists wind, vehicle movement, low-clearance conditions, and vibration during travel The CA-2X4SRNMO’s flexibility greatly reduces the risk of bending or damage during everyday driving, offering long-term reliability for commercial fleets, emergency responders, and amateur radio users.
- Flexible and durable whip construction resists wind, vehicle movement, low-clearance conditions, and vibration during travel The CA-2X4SRNMO’s flexibility greatly reduces the risk of bending or damage during everyday driving, offering long-term reliability for commercial fleets, emergency responders, and amateur radio users.