Abstract: A mobile radio communications device has a first crystal oscillator for providing a first master clock frequency for the timebase of a first communications system, a second crystal oscillator for providing a second master clock frequency for the timebase of a second communications system, and a phase locked loop connected between the first and second crystal oscillators and arranged to lock the first and second crystal oscillators together so that the two timebases cannot drift.

Abstract: A mobile radio communications device has a first crystal oscillator for providing a first master clock frequency for the timebase of a first communications system, a second crystal oscillator for providing a second master clock frequency for the timebase of a second communications system, and a phase locked loop connected between the first and second crystal oscillators and arranged to lock the first and second crystal oscillators together so that the two timebases cannot drift.

Abstract: A system for detachable mounting a component onto a printed circuit board comprises a printed circuit board having a through-hole, a compression spring constructed from, or coated with, an electrically conductive material, and a component having an electrical contact thereon. The compression spring having a first end of a diameter larger than the diameter of the through-hole, and a second end smaller than the diameter of the through-hole. The second end of the compression spring passes through the through-hole and is secured at its first end to the first side of the printed circuit board. The second end of the compression spring protrudes beyond the second side of the printed circuit board. When the component is placed against the second side of the printed circuit board, the compression spring is compressed and the desired electrical connection is formed.