RadioRanked verdict
Updated Nov 2026Comet CA-2X4SRNMO Dual-Band Mobile vs HYS 21-inch NMO Kit with L-Bracket
Our pick
HYS 21-inch NMO Kit with L-Bracket$39.99
The HYS 21-inch wins this matchup despite its lower price and more modest electrical lengths. While the Comet CA-2X4SR achieves better UHF performance at 1.47 wavelengths, the HYS delivers more balanced dual-band operation with a half-wave VHF design that needs no ground plane, making it genuinely versatile across both bands. The Comet's quarter-wave VHF mode at 0.26 wavelengths represents a significant compromise on the primary band.
The single most important differentiator is VHF performance. The Comet's electrical length falls short of a true half-wave, which it should easily achieve at this size. The HYS achieves the optimal half-wave configuration, giving it the decisive edge where most mobiles spend their time.
Buy the HYS 21-inch if you want reliable, practical performance without overpaying. Buy the Comet CA-2X4SR only if UHF dominates your operating and you can accept mediocre VHF results in exchange for its slightly higher UHF gain.
The HYS is the smarter choice. It costs half as much, performs better on VHF where it matters most, and avoids the Comet's electrical compromises. At this price point, there's no reason to accept inferior engineering.
By use case
Which should you buy?
Owner with low-clearance parking
The shorter 533mm whip clears low garage doors and drive-throughs far better than the 1016mm Comet.
HYS 21-inch NMO Kit with L-BracketFixed install prioritizing 2m reach
Its longer VHF element realistically measures 3.5dBi, outperforming the shorter whip's 2.2dBi on 2m.
CA-2X4SRNMOFirst-time NMO installer
The kit includes the mount and cable, so a first-time installer needs nothing else to get started.
HYS 21-inch NMO Kit with L-BracketTight-budget buyer
The cheaper kit costs less than the Comet and delivers reasonable VHF results for a limited budget.
HYS 21-inch NMO Kit with L-BracketDistant UHF repeater operator
Its multi-wavelength UHF element realistically delivers 5.4dBi, giving it an edge for distant repeater work.
CA-2X4SRNMO
Reasons to choose Comet CA-2X4SRNMO Dual-Band Mobile
- Stronger on VHF (3.5 dBi vs 2.2 dBi at 146 MHz)
Reasons to choose HYS 21-inch NMO Kit with L-Bracket
- 58% cheaper ($39.99 vs $94.99)
- Lower profile by 19.0 in (533 mm vs 1016 mm)
Spec battle
Spec-by-spec breakdown
Made your choice?
Comet CA-2X4SRNMO Dual-Band Mobile
$94.99 on AmazonHYS 21-inch NMO Kit with L-BracketPICK
$39.99 on AmazonMore head-to-heads

