Once you put the radio on your belt or in your pocket, you just made yourself into an RF black hole. Believe it or not, your body against the antenna blocks a good deal of the signal. This is why you see some police speaker microphones with the antennas on the mike instead of the radio.
That's true to an extent but, the 800 MHz frequencies those radios with the antenna mounted speakermics are used with are highly directional, far far more so than VHF frequencies would be, and they don't penetrate/pass-through our bodies nearly as easily as VHF freqs can and do hence the need to "get them higher" which means up above the body's interference meaning on the lapel-mounted speakermic.
I'd say that 800 MHz Radio Shack duckie is
amazing for pulling in stuff in the VHF range (and UHF too for that matter). It truly is a remarkable antenna for all that it offers. Maldol has some nice VHF-specific antennas, Comet has several, and then again there's the "King of the Hill" in my opinion, the Diamond RHC77A duckie/whip.
I've owned several of them and I have yet another one now for my Pro-164 and it's fantastic on VHF/UHF (since it's a Ham antenna, primarily) and it does fairly well on the 800 MHz band as well in my use.
