Abstract: An RF signal reception method includes mixing a received signal and a local oscillator signal to form a down converted signal. The down converted signal formed from the received signal is a modulated non-zero low frequency carrier referred to as a low frequency carrier desired signal. The low frequency carrier desired signal is extracted from undesired signals and interferers by using low or band-pass filters and the resulting signal is AC coupled to low frequency amplifiers for amplification. A digital representation of the low frequency carrier desired signal is then formed by digitally sampling at an analog-to-digital converter. The digitized desired signal may be further processed by digital signal processing devices for obtaining voice and/or data messages.

Abstract: Method and apparatus for affixing a circuit board with a protective chassis by affixing the circuit board substantially near the center of the long axis of the circuit board so that ends of the circuit board along the longer axis of the circuit board can flex freely uninhibited by the chassis. In the event that the circuit board-chassis unit is hit or dropped, since the mechanical shock is transmitted from the impact point on the chassis only to the approximate center of the circuit board, circuit components on the circuit board located away from the center of the circuit board will experience a reduced level of mechanical shock. Also, solder joints will experience less mechanical stress because there is less circuit board bending. This reduction in the level of mechanical shock to the circuit board increases the chances that the circuit components will not be damaged or become detached from the circuit board.