Offering a range of typically over 5km when paired with a suitable receiver, a highly compact transmitter module has been released by Radiometrix. The HMT2 transmitter is a multi-channel, narrowband design, suitable for use in many high power licensed and unlicensed UHF allocations worldwide.
Within a compact 66x23x9mm package, the Radiometrix HMT2 transmitter module offers a 500mW RF output in the UK 458MHz and the Danish /German 433MHz bands. The operating channel frequency is pin selectable - the HMT2 offers 16 parallel and 32 serial channels at frequencies between 458.525 and 459.1MHz.
The module draws just 350mA in transmit mode and less than 5µA on standby. It offers a data rate of 5kb/s and a DC-3kHz analogue interface for the standard module. The HMT2 module is fully shielded, enjoying high immunity to external interference, and conforms to ETSI EN 300 220-2 (radio) and EN 301 489-3 (EMC) standards. The HMT2 is a PLL synthesised transmitter clocked by a VCTCXO.
Thanks to its compact size and low power consumption, the HMT2 is suited for battery powered applications like hand held terminals, on-site paging systems and lone worker, security and fire alarms. Radiometrix also anticipates that the long range of the module will make it popular for data loggers, industrial telemetry and remote control systems and for vehicle data upload / download.
When used with a matching LMR2 receiver a one-way radio data link can be easily set up achieved over a distance of well over 5km (with a suitable antenna).