Kenwood TS-480 manual RX DSP filters

●RX DSP filters

In SSB, AM and FM modes, you can independently set high- and low-cut frequencies for the AF filters to suit operating conditions (slope tune).

Fig. 20 illustrates how slope tune works. When there are interfering signals in proximity to the target signal, you can use a high-cut filter and a low-cut filter to remove the signals above and below the target.

In SSB mode, installing the optional SSB narrow filter results in even better interference reduction. In AM mode if you select NAR, RX is possible using this SSB IF filter.

Target signal

Interference Interference

	Target signal
Low-cut	Hi-cut
Interference	Interference

Fig. 20: Slope tune in action

Listed below are the cutoff frequencies (unit: Hz) that can be chosen; default values are shown in bold.

SSB/FM
Low-cut	0	50	100	200	300	400	500	600	700	800	900	1000
Hi-cut	1000	1200	1400	1600	1800	2000	2200	2400	2600	2800	3000	3400	4000	5000
AM
Low-cut	0	100	200	500
Hi-cut	2500	3000	4000	5000

In CW and FSK modes, the AF filters function as a VBT, changing bandwidth without altering the center frequency. In CW mode, the center frequency is coupled to the CW pitch, whereas in FSK mode it is determined by the FSK tone and FSK shift frequencies.

Fig. 21 shows how it is possible during CW operations to extract a target signal from surrounding interference by changing the AF filter bandwidth (WIDTH).

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