Telex USR-100 operating instructions Posi Phase Diversity, Antennas, Computer Controlled Channels

Posi Phase Diversity

The USR-100 receiver utilizes Telex’s patented Posi Phase auto diversity circuit. Unlike other types of diversity which receive with only one antenna at a time, Posi Phase utilizes both antennas at all times. This results in a stronger signal from the microphone for cleaner audio and greater range.

If the microphone signal begins to go out of phase (a common cause of “drop outs” with other types of diversity) the Posi Phase circuit adjusts the phase angle between the two antennas’ receiving circuits to prevent phase cancellation. This action is indicated by the 0 and 180 degree diversity lights on the front panel

Antennas

There are two TNC type antenna connectors on the rear panel. These connectors are superior to the more common BNC connectors, both electrically and mechanically. TNC connectors are becoming the standard of the industry due to their heavy use in the Cellular Phone industry. Quarter wave antennas are supplied for normal use or an optional antenna accessory kit can be used to rack mount the anten- nas. Optional half wave antennas with coax can be used for remote installations. Both antennas must be used as both are active at all times, unlike other types of diversity that only use one antenna at a time.

Computer Controlled Channels

The VCO (Voltage Controlled Oscillator), which is the heart of any Phase Locked Loop Receiver, is controlled by an on-board PIC microprocessor. Each individual USR-100 RF stage tuning element is also under the direct control of the microprocessor. This directs the receiver to undergo an “Automatic Self Tune” step each time the channel is changed. This is unlike many receivers on the market that simply have “wide band” designs that allow interference to enter the most sensitive stages of a receiver to cause inter-modulation and noise. Other items under processor control are the channel selection, spacing and display, the AF and RF displays and diversity operations. This marriage of digital precision with real analog sound provides the user with the best of both technologies.

-2-