The NDB Transmitters (JTM-30C and JTM-50C) are available as Single and Dual Transmitters. As Dual Transmitter they have two complete transmit chains with fault detection/reporting and automatic changeover.

All versions are built upon a totally new concept for NDB transmitters utilizing digital Exciters and PC controls. The transmitters have, among other facilities, following main features:

    The carrier frequency may be tuned in steps of 1 Hz from 190 kHz to 2 MHz

    Frequency generation by Direct Digital Synthesis featuring high linearity and stability of carrier and modulation, low noise and excellent frequency accuracy

    The output power is 100 W (respectively 1000 W) Peak Envelope Power (PEP)

    The Exciter provides full power control of the carrier

    The transmitters operate with N0N/A2A or N0N/A3A emission. MSK modulation available as an option

    A Timer function enables four different Morse sequences:

"    Continuous transmission of Morse keying, with automatic keying sequence repetition

"    Transmit one time Morse keying sequence only

"    Transmit repeated Morse keying sequences during a specified interval

"    Transmit the Morse keying sequence once for every specified interval

    All versions of transmitters are equipped with functions for monitoring the transmitter in operation, carrier level, modulation and failure conditions

    Flexible control and monitoring from an attached PC via RS485, or from any remote connected Internet PC via locally dedicated NDB PC

    Through the RS-485 remote control interface all parameters above may be read and/or programmed

   

The RS-485 remote control interface also provides an event log that records all system events, such as restart, parameter changes and error events.

The NDB Transmitters have built-in non-volatile memory sufficient for storage of the entire transmitter configuration enabling stand-alone un-attended operation. Saving the configuration in solid-state memory is controlled via the PC interface.

In addition to the PC interface, the NDB Transmitters also include Remote Control Unit interface that can be attached via a separate galvanic isolated port to provide simple operation of the transmitter from remote location(s). The Remote Control Units may be chained to more than one location.