D Series: DB900 High Performance Base Station

Radio

The D Series Base Station radios have been designed to meet worldwide regulatory guidelines, including FCC.

This fully synthesised radio is programmable in 6.25/7.5 kHz increments to accommodate various worldwide channel spacings. The receiver section has a wide tuning range with an excellent signal-to-noise ratio.

Exceptional frequency stability is achieved by intelligent microprocessor controlled temperature compensation. An extended operating temperature range of -30 to 600 degrees C makes the unit ideal for commercial and industrial applications.

Modem

The in-built modem includes a custom DSP developed for data communications over narrow band radio systems. This system offers minimum occupied bandwidth and optimal data integrity (using the standard HDLC protocol with CCITT CRC error detection) inhibiting the transfer of any rogue unwanted data caused by interference or squelch headers / tails.

The Trio DSP provides:

• the interface between the asynchronous RS232 user communication and the synchronous radio link layer.
• an inbuilt multipexer / router which allows for simultaneous transportation of multiple protocols over the one radio network.

Applications and Operation

The DR900 data radios form the basis of the D Series Base Stations, thus providing all the features and performance figures of these high performance radio modems. The use of this common radio platform ensures complete system integration.

The RF power amplifier module comes from our Hot Standby base stations and is constructed from a pair of high reliability linear power modules. The two amplifiers are combined using microwave hybrid coupling techniques with no active or moving components and are hence permanently connected to the antenna.

The low noise receiver pre-amplifier also comes from our Hot Standby Base Station and uses the same techniques as the transmitter power amplifier. No active circuits or mechanical RF changeover devices are employed and the output of the LNA is fed to both radio receivers.

A display panel mounted behind the front panel houses LED array indicators showing all vital signs of the unit. The display can be de-energised when not in use to save on power consumption.

Housed in a rugged 19” rack mountable module, the D Series Base Stations offer excellent performance and reliability.

Note - Model Code change: Model codes previously depicted as, eg: 900DR, are now represented as, eg: DR900.

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