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Kenwood TS-480HX User Manual

Page 26

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26

Interference

Interference

Target signal

Interference

Interference

Target signal

Low-cut

Hi-cut

Fig. 20: Slope tune in action

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.

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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