Comet SMA-24J (SMA-Female) vs Nagoya NA-701G (GMRS)

The Comet SMA-24J is the clear winner for general amateur radio use, though the choice ultimately depends on your intended application.

The most important differentiator is electrical length and honest specifications. The Comet achieves 0.65 wavelengths on UHF, delivering realistic 2.9 dBi gain that matches its claimed performance. The Nagoya, by contrast, is only 0.22 wavelengths at GMRS frequencies and significantly overstates its gain by about 2.6 dB, claiming 2.15 dBi when its physical length supports only minus 0.4 dBi. This is a fundamental credibility problem that extends beyond just GMRS use.

The Comet's longer 450 mm design makes it a versatile dual-band antenna performing respectably on both VHF and UHF, though VHF performance is limited at quarter wave. The Nagoya's 140 mm length is genuinely optimized only for GMRS frequencies and would underperform significantly on other bands.

Buy the Comet SMA-24J if you operate across multiple bands or want an honest all-rounder antenna. Buy the Nagoya NA-701G only if you operate exclusively on GMRS and prioritize maximum portability, accepting its compromised performance and misleading specifications.

The Comet is the safer, more capable choice for most amateur operators.