Abstract: A closed positive pressure evaporation system for evaporating samples in preparation for analysis comprising a plurality of sample vials where each sample vial has associated therewith an inlet and an outlet. An chamber is provided having a heat source and a holder for positioning and holding the sample vials with reference to the heat source. A distribution manifold is connected via tubing to the inlet of each sample vial for distributing purified inert gas, such as Nitrogen, to each sample vial held by the holder in the chamber. A collection manifold is connected via tubing to the outlet means of each sample vial for collecting purified inert gas, such as Nitrogen, and gases from each sample vial connected to the distribution manifold. The chamber, distribution manifold and collection manifold coacting to expose a sample in each sample vial to only purified inert gas, such as Nitrogen, during the evaporation of the sample.

Abstract: A television frequency-to-radio frequency transceiver is provided for receiving television audio signals via the airwaves and converting them to AM or FM radio frequency signals for transmission by the airwaves to a nearby AM or FM receiver. An antenna matching circuit and bandpass filter network are provided to enhance reception of signals in the lower VHF band. Selectable TV channels and selectable AM and FM radio frequencies are provided by means of digitally controlled television and AM and FM radio frequency synthesizers. Stereo signal processing and secondary audio programming signal processing are also provided. An external whip antenna is used for receiving signals and an internal loop antenna is used for transmitting the signals.