The FDM-DUOr is a shortwave receiver which uses state-of-the-art SDR technology, but which can be used like a traditional radio. Familiar operating controls like a large VFO knob, dedicated knobs for volume, filters and other functions as well as pushbuttons for often used settings confer the FDM-DUOr an ease of use like a classical receiver. Features like a fast AD converter and powerful digital processing capabilities are the basis for excellent reception capabilities, like they are known from the FDM-S2 and FDM-DUO.
The receive frequency range is from 10 kHz to 54 MHz. The two antenna inputs are connected to optional preselectors which are selected according to the tuned frequency. A TCXO is used for good frequency stability, the side band noise of the oscillator is a very low -130 to -136dBc, resulting in a low noise floor and excellent sensitivity. Alternatively an external 10 MHz precision clock reference can be used as master clock.
Depending on how the FDM-DUOr is used - with or without computer - different operating modes are available: without computer USB, LSB, CW, AM and FM narrow, with computer additionally WFM and DRM can be received. DRM is available with the supplied software, no complicated installation of additional software is needed.
Further hardware features of the FDM-DUOr are worthy of professional radios. The precision clock input was already mentioned. A USB CAT interface allows remote control with various software, the CAT protocol is fully documented. A "Mute" input stops the receiver when a nearby transmitter is keyed, providing seamless integration into an existing amateur radio station. Connections for headphones and line out are also provided. The receiver requires a 13.8Vdc supply, max. current is approx. 500 mA.