Comet SBB-1NMO Compact Dual-Band Mobile vs Retevis Heavy-Duty Fiberglass GMRS Mobile

The Retevis Heavy-Duty Fiberglass is the clear winner here, but the choice depends on your radio band.

The critical difference is electrical length. The Comet SBB-1 is a dual-band compromise: it works reasonably well on UHF at 5/8 wavelength (4.7 dBi realistic), but its VHF side is severely compromised at only 0.20 wavelengths, delivering just 0.7 dBi. The Retevis is purpose-built for GMRS at 1.90 wavelengths, achieving a realistic 6.3 dBi and justifying its claimed 6.5 dBi gain.

If you operate primarily on UHF or GMRS, the Retevis wins decisively. If you need VHF performance, the Comet is the least-bad option available at this price point, though it is inherently limited. The Retevis costs 29 percent more and is physically larger, which matters on some vehicles. Owners report satisfaction with both units (4.4 and 4.5 stars respectively across meaningful sample sizes).

Buy the Comet SBB-1 if you genuinely need dual-band coverage and VHF is unavoidable. Buy the Retevis Heavy-Duty if you operate GMRS or primarily UHF and can accommodate the extra length.

The Retevis is the sounder general purchase.