3-1-3 PRE-AMPLIFIER CIRCUITS (RF UNIT)The IC-756PRO has 2 gain levels of pre-amplifier circuits.One has 10 dB gain over a wide band frequency range andthe other one has 16 dB gain for the 21–28 MHz bands.When the [PREAMP] switch is set to [PRE1] or [PRE2], thesignals are applied to the pre-amplifier 1 (Q441, Q442) orpre-amplifier 2 (IC451) circuit, respectively. Pre-amplified orbypassed signals are applied to the RF amplifier circuits(Q501, Q601).