Comet CH-32 (BNC) vs Diamond RH77CA (BNC)

The Diamond RH77CA is the clear winner here. The single most important difference is electrical length: at UHF, the Diamond reaches half-wave efficiency at 0.55 wavelengths with realistic gain of 2.8 dBi, while the Comet is severely compromised at only 0.06 wavelengths with -5.3 dBi. On VHF both antennas are electrically short, but the Diamond's 0.19 wavelengths is less crippled than the Comet's 0.02 wavelengths. The Comet's tiny 44 mm form factor makes it genuinely pocketable, but that advantage disappears the moment you need actual performance.

The Diamond costs six dollars less, has more than three times the review count from owners, and owners report slightly higher satisfaction. Critically, its 381 mm length is still portable on a handheld despite the dramatic performance improvement.

Buy the Comet only if pocket size absolutely trumps performance and you operate primarily on VHF where both are weak. Buy the Diamond if you actually want the antenna to work, especially on UHF where it functions as a proper half-wave radiator.

Get the Diamond RH77CA. It outperforms significantly, costs less, and owners prefer it.