D Series: DH900 Hot Standby Base Station

Radio & Modem

The D Series Hot Standby 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 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.

Applications

Operation and Construction Trio's Hot Standby Base Stations provide the basis for a high reliability data radio modem installation. They are purpose designed to minimise common component failures.

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

Microstrip hybrid combining networks, rather than relays, are used to ensure maximum reliability of radio frequency changeover circuits. This ensures a ‘soft fail’ operation.

The RF power amplifier module 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. Both modules run from seperate regulated and over-voltage protected supplies.

The low noise receiver pre-amplifier 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 indicator units showing all vital signs of the unit. The display module also contains the power supply pre-conditioning components and self healing short circuit protection.

The hot changeover logic is contained on a single circuit board employing highly reliable static gate array technology which constantly monitors both RF characteristics and data integrity. This PCB also contains solid state opto coupled RS232 changeover circuits running from dual gated and fused power rails.

The dual redundant base stations can be configured with or without inbuilt diplexers and receiver preselectors, accommodating for individual TX / Rx combining antennas, seperate combining Tx and Rx antennnas, or a single combining Tx / Rx antenna.

Housed in a rugged 19” rack mountable module, the D Series dual redundant 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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