 The allocated bands for amateurs are many megahertz wide, allowing for high-fidelity audio transmission modes (FM) and very fast data transmission modes that are unfeasible for the kilohertz-wide allocations in the HF bands.While "line of sight" propagation is a primary factor for range calculation, much of the interest in the bands above HF comes from use of other propagation modes.A signal transmitted on VHF from a hand-held portable will typically travel about 5–10 km depending on terrain.