Use of Microcomputer This IC-280E is the world's first amateur transceiver with a P-channel MOS 4-bit microcomputer. Frequency control, band-edge detection, and the display are accomplished by the microcomputer. The 3-channel memory is controlled electrically by the use of a 256-bit RAM area. The circuits for these IC-280E functions are equivalent in capability to conventional circuits having a large number of C-MOS MSI's. Separable Control Unit The control portion (front panel) of the IC-280E can be separated from the rest of the unit, and the two parts can be connected with a cable. The control unit is approximately one-third of the whole unit; therefore, the IC-280E can be easily mounted almost anywhere in a car. Superior Receiving Characteristics The use of newly developed low-noise and large dynamic range junction FET's (for the RF amplifier and the first mixer) and of helical cavity filters (for the antenna and RF circuits) provides excellent sensitivity and intermodulation distortion characteristics. A pair of high quality monolithic crystal filters facilitates very stable receiving and excellent durability. Highly Stable Transmitting Characteristics Both the directly amplified VCO output without the use of multipliers or mixers and the use of a power module in the PA unit produce very clean transmitting signals without spurious radiation. RF power is selectable 10W (HIGH) and 1W (LOW).