RadioRanked verdict
Updated Aug 2026HYS 21-inch NMO Kit with L-Bracket vs Retevis Heavy-Duty Fiberglass GMRS Mobile
Our pick
Retevis Heavy-Duty Fiberglass GMRS Mobile$69.59
The Retevis Heavy-Duty Fiberglass is the clear winner for GMRS use, though the choice depends on your radio service and vehicle constraints.
The single most important differentiator is electrical length. The HYS at 0.26 wavelengths on VHF is a compromise antenna that trades performance for compactness. The Retevis at 1.90 wavelengths on GMRS delivers genuine multi-wavelength performance with realistic gain around 6.3 dBi, supporting its claimed 6.5 dBi figure honestly. The HYS claims 2.15 dBi, which aligns with what its quarter-wave design should produce on VHF, but at UHF it becomes a full-wave radiator where its performance profile shifts unexpectedly.
Buy the HYS if you need a compact dual-band VHF/UHF mobile antenna for tight vehicle installations where the 21-inch form factor is essential. Buy the Retevis if you operate GMRS or have space for a 48-inch antenna and want genuine multiband performance with realistic gain and efficiency.
The Retevis is the better engineered antenna for its intended purpose. The HYS is useful only if space forces your hand. Given nearly identical scores despite the Retevis's physical and electrical superiority, the choice ultimately tracks your installation constraints and frequency band.
By use case
Which should you buy?
New operator needing a complete kit
This kit provides the necessary mount and cable for easy first-time installation.
HYS 21-inch NMO Kit with L-BracketOff-road enthusiast requiring maximum reach
The longer whip ensures superior signal strength when maximizing antenna height.
Retevis Heavy-Duty Fiberglass GMRS MobileBudget-conscious operator prioritizing cost savings
At a significantly lower price point, this kit offers excellent value for VHF/UHF use.
HYS 21-inch NMO Kit with L-BracketGMRS specialist needing high performance and range
Its specialized design provides optimal gain and coverage specifically for GMRS frequencies.
Retevis Heavy-Duty Fiberglass GMRS MobileOperator with limited vehicle space or low clearance
The shorter, more compact size makes it ideal for daily driving in urban environments.
HYS 21-inch NMO Kit with L-Bracket
Reasons to choose HYS 21-inch NMO Kit with L-Bracket
- 43% cheaper ($39.99 vs $69.59)
- Also covers VHF (146 MHz)
- Lower profile by 27.2 in (533 mm vs 1224 mm)
Reasons to choose Retevis Heavy-Duty Fiberglass GMRS Mobile
- Also covers GMRS (465 MHz)
Spec battle
Spec-by-spec breakdown
Made your choice?
HYS 21-inch NMO Kit with L-Bracket
$39.99 on AmazonRetevis Heavy-Duty Fiberglass GMRS MobilePICK
$69.59 on AmazonMore head-to-heads