9 REJECTING INTERFERENCE

ATTENUATOR

Attenuator reduces the level of received signals. This function is useful when interference from adjacent frequencies is strong.

Press [ATT] to toggle Attenuator ON or OFF.

“ATT” appears when the function is ON.

The ON/OFF setting will automatically be stored in the current band. Each time you select the same band, the same setting will automatically be selected.

The frequency range of each band is shown below.

Frequency range (MHz)

Frequency range (MHz)

 

 

 

0.03

~ 2.50

14.50 ~ 18.50

2.50

~ 4.10

18.50 ~ 21.50

4.10

~ 7.50

21.50 ~ 25.50

7.50 ~ 10.50

25.50 ~ 30.00

10.50

~ 14.50

30.00 ~ 60.00 (TS-570S)

PREAMPLIFIER

Switching Preamplifier OFF also may help to reduce interference from adjacent frequencies.

Press [PRE-AMP]to toggle ON or OFF.

“PRE-AMP” appears when the function is ON.

The ON/OFF setting will automatically be stored in the current band. Each time you select the same band, the same setting will automatically be selected.

The frequency range of each band is the same as for the Attenuator. The default of Preamplifier is OFF for the bands from 30 kHz to 7.5 MHz, and ON for the bands from 7.5 MHz to 60.0 MHz (TS-570D: 30.0 MHz).

Note: Switching Preamplifier OFF has the same effect as activating the AIP function on other KENWOOD transceivers.

DSP TOOLS

KENWOOD digital signal processing (DSP) technology is used for the functions described in this section.

CHANGING RECEIVE BANDWIDTH

For improving the interference reduction capability, this transceiver also provides audio frequency (AF) filters designed using DSP technology. When in SSB, FM, or AM mode, you can change the filter bandwidth by altering its low cut-off frequency and/or high cut-off frequency. For CW and FSK modes, you can change the filter bandwidth by directly specifying a bandwidth. Changing the filter bandwidth does not affect the current receive frequency.

You can also monitor signals trimmed off by the above DSP filters. Consult “PROGRAM FUNCTION BUTTON” {page 49} and assign the DSP Filter Monitor function (No. 53) to any [PF] button. Press and hold the [PF] button to monitor the trimmed signals; the DSP filters will restore the default bandwidths. Release the button to quit the function. You may use this function to check how adjacent frequencies are in use.

SSB/ FM/ AM Modes

1 Select SSB, FM, or AM mode.

2Turn the DSP SLOPE (LOW) control clockwise to raise the low cut-off frequency, or counterclockwise to lower the low cut-off frequency.

USB pass band

f

USB pass band

f

Turn the DSP SLOPE (HIGH) control clockwise to raise the high cut-off frequency, or counterclockwise to lower the high cut-off frequency.

 

USB pass band

 

f

 

USB pass band

 

f

Adjust

Frequency Selections

DSP SLOPE

10, 50, 100, 150, 200, 250, 300, 350,

(LOW) control

400, 450, 500, 550, 600, 650, 700,

 

750, 800, 850, 900, 950, 1000 Hz

DSP SLOPE

1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7,

(HIGH) control

1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2,

 

3.4, 3.6, 4.0, 4.4, 5.0 kHz

The default cut-off frequencies depend on the current positions of the DSP SLOPE controls.

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Kenwood TS-570D instruction manual Attenuator, Preamplifier, DSP Tools, Rejecting Interference, Changing Receive Bandwidth