|Discontinued Amateur Base Transceivers|
IC-756 Pro III Roofing Filter
The Icom IC-756 ProIII uses a fundamental-mode monolithic crystal filter for the roofing filter. Although it is more expensive than overtone-mode filters, the fundamental-mode filter has a better shape factor and is less susceptible to intermodulation distortion under strong-signal conditions. This is the same 15kHz crystal filter used in the IC-7800.