Key Facts

  • Frequency independent production in all 4 or 8 production channels
  • Narrowband receivers can offer a better sensitivity compared to wideband receivers
  • Narrowband receivers consum less ressources, as no DDC is required
  • Possibility to add "virtual" receivers
  • Signal processing even when receiver operation is in scan/step mode

Narrowband Receiver Control (NRC) Option

This receivers are often referred to as :

  • Offline Receiver
  • Drop off Receiver

In the basic version the production channels processes signals inside the wideband stream of the receiver. To monitor signals outside this bandwidth 4 or 8 additional narrowband receivers can be added.


The operator can choose the emission/frequency in the GUI (directly in the spectrogram, from classification results or from the station list) and decide if it should be extracted from the wideband input by using a DDC-channel or by using NB-receivers.

Each extracted narrowband channel is marked in the wideband spectrogram. An interactive interface for processing and fine-tuning the narrowband signal is available in the GUI. This interface can also display a zoomed-in spectrogram of the single channel with much higher spectrum resolution then in the wideband spectrogram.

The required frequency of the channel can be selected directly in the wideband spectrogram by using the mouse or by entering numerical values directly in the channel fine-tuning interface.

It is possible to use DDC and narrowband receivers side by side.

In larger systems the NB-receiver can be simulated by an external DDC server or a receiver that is already able to deliver multiple IQ IF streams

NB-RX vs. DDC-Server

Both solutions for NB-signal extraction have advantages and disadvantages.
DDC-server usually offer more channels and higher flexibility. The disadvantage of the DDC-server is that it can extract only signals from the currently available frequency range of the wideband receiver. This makes it unusable if the receiver is in sweep or scan mode.

NB-receivers are completely independent from the current frequency range of the wideband receiver, and they offer a better sensitivity compared to wideband receivers.