Kenwood TS-B2000, TS-2000X Rejecting Interference Notch Filter SSB, Auto Beat Cancel SSB/ AM

12 REJECTING INTERFERENCE

NOTCH FILTER (SSB) MANUAL BEAT CANCEL (CW/ SSB/ AM)

Auto Notch filter automatically locates and attenuates any single interfering tone within the receive pass band. This function operates digitally at the IF filter level, hence it can affect your S-meter reading and may also affect (slightly attenuate) your desired signal. However, controlling the AGC level by notching out the strong interfering beat signals could bring up the desired SSB signal that is covered by the interfering beat signal. If the interfering tone is weak, you may find that Beat Cancel eliminates them more effectively.

Receive pass band

Interfering tones

Desired signal

BeforeAfter

Press [A.N./ LEVEL] to toggle the Auto Notch Filter ON and OFF.

•“A.N.” appears when the function is ON.

•The interfering beat signals are notched out.

If the interfering beat signals change the tone frequency randomly, you can adjust the Auto Notch level.

Press [FUNC], [A.N./ LEVEL] to access the Auto Notch level adjustment, then turn the MULTI/ CH control to select the level from FIX, and 1 to 4.

Level 1 is the slowest beat tone tracking speed and Level 4 is the fastest. FIX terminates the beat tone tracking. Adjust this pamameter manually to remove the beat signal if necessary.

Press [FUNC], [B.C./ MANUAL], then turn the MANUAL BC control to select the single Beat Cancel frequency manually. You can select the beat cancel frequency from approx. 300Hz to 3000 Hz by turning the control. Turn the control clockwise to select a higher frequency and counterclockwise to select a lower frequency.

Since the DSP Beat Cancel processes the incoming signals at the AF stage, strong beat signals may control the AGC, then weaken the target signal level. In this case, use the Auto Notch Filter instead, to remove the beat signal from the IF passband filter.

Note: While adjusting the MANUAL BC control, the transceiver clicks. This is not a malfunction.

NOISE REDUCTION

(N.R.1: ALL MODES, N.R.2: SSB/ CW/ FSK/ AM)

This transceiver provides two types of Noise Reduction functions (1 and 2) for reducing random noise which interferes with the desired signal. Trying them both is the easiest way to judge which function works more effectively under the current conditions. Normally, select Noise Reduction 1 (Line Enhanced) in SSB mode and Noise Reduction 2 (SPAC) in CW mode.

Press [N.R./ LEVEL] to toggle between Noise Reduction 1, Noise Reduction 2, and OFF.

•“N. R. 1” or “N.R. 2” appears, depending on which function is selected.

■Setting the N.R. 1 Level Adjustment

The Noise Reduction 1 (Line Enhanced Method) uses an adaptive filter to reduce the noise element from the received signals. When the S/N ratio is reasonably good in SSB, using N.R.1 will improve the S/N further.

AUTO BEAT CANCEL (SSB/ AM)

Auto Beat Cancel uses an adaptive filter and attenuates more than one cyclic interference within the receive pass band. The adaptive filter changes its characteristics according to the nature of the signal being received at any given moment. You can use automatic Beat Cancel when in SSB or AM mode.

Receive pass band

Interfering tones

Desired signal

BeforeAfter

Press [B.C./ MANUAL] to toggle the Auto Beat Cancel ON and OFF.

•“B. C.” appears when the function is ON.

•If desired, you can manually control the beat cancel frequency.

While N.R. 1 is ON, you can further adjust the noise reduction level by pressing [FUNC], [N.R./ LEVEL], then turn the MULTI/ CH control to select the level from 1 to 10 or AUTO. The default is AUTO.

■Setting the N.R. 2 Time Constant

You can change the correlation time for Noise Reduction 2 (SPAC). When in SSB mode, select the correlation time that allows you to hear signals with more clarity. When receiving CW, it is best to select the longest correlation time that allows reliable reception. The longer the correlation time, the better the S/N ratio.

When Noise Reduction 2 is ON, press [FUNC], [N.R./ LEVEL], then turn the MULTI/ CH control to select the correlation time from 2 ms to 20 ms. The default is 20 ms.

Note:

◆Using Noise Reduction 2 in SSB mode may lower the clarity of signals or induce pulse noise, depending on the conditions.

◆Only N.R. 1 is available for the sub-receiver. However, the level cannot be adjusted.

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