NR140C SWR Sweep

I ran an SWR sweep for this antenna. It's a mono band gain antenna for the Ham 1.25M band. It's about the same size as the Comet CA-2x4SR people claim is resonate on the same band, it's not marketed by Comet for the band. I suspect due to the similar size and some of the design details might explain why this might be the case.

There is no datasheet for the antenna so I had to make one of my own:

The Diamond NR140 is a high-gain, monoband mobile antenna for the 1.25-meter (220 MHz) amateur radio band.

The following specifications apply to the NR140BNMO model, which uses an NMO mounting base. 

Key specifications

• Frequency Range: 222–225 MHz

• Antenna Type: Mobile vertical antenna, monoband

• Gain: 3.8 dBi

• Power Rating: 100 watts

• Height: 36.200 inches (approx. 3 feet)

• Element Phasing: 1/2 + 3/8 wave

• Mounting Base: NMO (New Motorola Mount)

• Connection: NMO mobile mounting base not included; compatible with NMO mounts.

• Fold-Over Feature: Yes. The fold-over design is for manual use, and the antenna is not built to withstand impact from objects like tree limbs at speed.

• Magnet Mount Compatibility: Yes, though the magnet mount is sold separately. 

Design and features

• Construction: The antenna is described as strong and well-constructed, with good build quality reported by some users.

• Performance: The NR140 is a high-quality monoband antenna designed for optimal, no-compromise performance on a single band. It is more efficient than multi-band antennas in its specific frequency range.

• Appearance: The antenna has a natural, metal finish.

• Manufacturer: Diamond Antenna, a manufacturer with a reputation for producing durable products.