Abstract: A system for the automatic establishment of a shortwave telegraphy signal connection between two transmitter-receiver stations within a frequency range subdivided into several channels. Both stations use their receiver to determine objective measurement values reflecting the transmission conditions over the individual channels. Active and passive channel analysis of the actual quality of the signal transmission is determined at each channel. The transmitter of the calling station is automatically tuned to the channel which corresponds to the best channel quality stored in its memory. A predetermined time after transmitting the call signal, the calling station switches to reception and upon reception of an acknowledgment signal from the counter station automatically begins the message transmitting-and-receiving operation. If after a predetermined time no acknowledgment signal is received, the transmitter automatically switches to the channel stored in its memory with the next best channel quality value.

Abstract: Normal paraffins are separated from a gas oil-containing hydrocarbon vapor feed stream having 16 to 25 carbon atoms per molecule in a constant pressure process employing a molecular sieve adsorbent and n-hexane for purging and for dilution of gas oil-containing feedstock. Cocurrent purge effluent is used to provide a source of such n-hexane diluent, thereby reducing the equipment size and energy consumption for processing of the n-hexane purge recycle stream and increasing adsorbent utilization or the efficiency of the adsorption process.