Passband frequency range expansion through LOW-CUT/HI-CUT, WIDTH/SHIFT. Interfering signal removal and desired audio-quality adjustment, as well as more convenient operation in digital mode. Operation with LOW-CUT / HI-CUT in SSB/AM/FM mode, WIDTH/ SHIFT in CW mode, and WIDTH function in FSK/PSK mode. Change to WIDTH/SHIFT operation as in CW mode also possible in SSB/SSBDATA mode. Selection of roofing filter (270Hz*/500Hz/2.7kHz/6kHz/1 5kHz) can be automatic to match IF filter passband width or manual to selectable frequencies.
(* 270Hz when option mounted)

Switching is possible between 3 kinds of IF filter shapes: Medium/ Soft/Sharp. Switching is also possible for post-demodulation voiceaudio between 3 kinds of AF filter passbands: Medium/Wide/ Narrow. Combinations of these settings can adjust the sharpness of the demodulation signal.

This is a narrow bandwidth peak filter operated during receive in CW mode. When intelligibility is low due to noise, it has the effect of floating the target signal and increasing intelligibility. The central frequency is linked to the pitch frequency, and can be given a maximum peak gain of +6dB.

A notch filter that operates in the IF stage. By eliminating strong interfering signals, it allows weak target signals to stand out. Damping range can be switched between three levels: Narrow/Middle/Wide, enabling operation to match interference conditions.

In addition to conventional NR1/NR2 noise reduction, NR1 comes equipped with noise reduction using spectral-subtraction, which focusses on noise reduction in voice-audio system modes. The optimum noise reduction method is applied for each receive mode.

A noise blanker reduces crackling, pulse-type noise. The TS-890S includes two kinds of noise blankers: NB1, which processes analogue signals, and NB2, which carries out digital processing in the IF stage using DSP. Furthermore, selection of NB2 can be made from two kinds of NB with different operating principles. Either NB1 or NB2 can be used depending on noise conditions, or both can be used simultaneously.

While a notch filter (IF stage) is effective for a single strong beat, beat cancelling (AF stage) shows results on multiple, comparatively weak beats. BC1 is effective on weak beats and continuous beats, while BC2 is effective on intermittent beats like CW signals.

A function to recover from suppression that happens when pulse noise is included in a receive signal.