For narrowband antennas, the standardized 50 Ω output of HF transmitters has to be adapted to varying impedances of the antenna over its frequency range. This adaption will be performed by specific antenna tuning units (ATU).
HMK provides ATUs for 150 W, 500 W and 1kW HF for the HF Radio Series 3000 transmitters and transceivers.
- ATU 3015 (for 150 W HF transceiver)
- ATU 3050 A (for 150 W and 500 W HF transceiver)
- ATU 3050 C (for 500 W transceiver – especially designed for use in CALZONI submarine pressurized shelter)
- ATU 3050 E (for 500 W transceiver – constructed to withstand extreme shock situations as they can occur on submarines)
- ATU 3050 H (for 500 W HF transceiver - constructed to withstand extreme shock situations as they can occur on submarines)
- ATU 3100 HVST (for 1 kW HF transceivers)