On my attached picture, you can see both x36 scanners on ProScan. You'll notice that both scanners are monitoring the exact same system, even on the exact same frequency. Both scanners are using the Radio Shack magnetic mobile mount antenna, mounted on my roof. Both scanners are also attached to separate GRE Super Amplifiers. Since both scanners are attached to the same equipment, on the same system and frequency, why would the signal strength be different on each radio? I've noticed that while monitoring both radios at the same time, the 536 has cleaner audio. Would that mean that the 536 is more sensitive than the 436?