Abstract: A tuning arrangement in a radio receiver includes a front-end circuit having a tunable band-pass filter that is capable of tunably selecting channels within at least one frequency band of an RF signal. A noise source coupled to an input of the tunable band-pass filter introduces a wide-band noise signal into the front-end circuit. A signal detector coupled to an output of the front-end circuit measures at least one signal power associated with a filtered noise signal derived from the wide-band noise signal. A tuning controller, coupled to the tunable band-pass filter by a tuning control signal, adjusts the tuning control signal in response to the at least one measured signal power for tuning the tunable band-pass filter to a desired filter response.

Abstract: The invention concerns a method of improving the dynamic properties of compacted and sintered products having a density between 6.8 and 7.6 g/cm3, preferably between 7.0 and 7.4 g/cm3. According to this method an iron based powder, graphite and a solid particular lubricant having a vaporizing temperature less the sintering temperature, preferably less than about 800° C. is compacted and sintered and the maximum particle size of the lubricant is selected so that the largest pores of a compacted and sintered product prepared from the composition are equal to or less than the largest pores obtained in a compacted and sintered product prepared from the composition without lubricant. The invention also concerns composition of an iron based powder, graphite and a solid particular lubricant having a vaporizing temperature less the sintering temperature, preferably less than about 800° C. and a maximum particle size less than about 0.

Abstract: A directional valve for a breathing apparatus, such as an anaesthetic machine, has a valve seat with a valve port and a valve plate resting loosely on a valve seat. The valve plate has a soft, pliant area on its surface in contact with the valve seat and a relatively rigid area across the valve port.