I am looking for a handheld Spectrum Analyzer BK2650 (Link1 below) or Field Strength Analyzer Protek 3290 (Link2). The problem is that I cannot see the major differences between them, yet there's a major price difference of $1000-2000. Can anyone tell me what the major differences between a spectrum analyzer and Field Strength Analyzer? Is it in demodulation ways, sweep speed, display freq span, or some extra stuff that I do not need as an amateur/electronics hobbyist? Thanks.