Noise Blanker, Digital Noise Limiter DNL

10 REJECTING INTERFERENCE

BEAT CANCEL (SSB/ FM/ AM)

Two types of Beat Cancel DSP filters are available. Beat Cancel 1 (BC1) is effective for removing a weak beat or continuous beat signals. Beat Cancel 2 (BC2) is effective for removing intermittent beat signals, such as CW signals.

Filter pass band (AF)

Interfering tone

Desired signal

BeforeAfter

Press [BC/ CW.T] to cycle through Beat Cancel 1, Beat Cancel 2, and OFF.

•“1tBC” or “BCs2” appears when the Beat Cancel function is ON.

•The interfering beat signals are removed.

NOISE REDUCTION (ALL MODES)

This transceiver provides 2 types of Noise Reduction functions (NR1 and NR2) 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 NR1 (Line Enhanced) in SSB mode and NR2 (SPAC) in CW mode.

Press [NR] to toggle between NR1, NR2, and OFF.

•“1tNR” or “NRs2” appears, depending on which type of noise reduction filter is selected.

■Setting the NR1 Level Adjustment

The NR1 (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 the NR1 will improve the S/N further.

While NR1 is ON, you can further adjust the noise reduction level by pressing [NR] (1 s), then turn the MULTI control to select the level from 1 to 9 or AUTO. The default is AUTO.

■Setting the NR2 Time Constant

You can change the correlation time for NR2 (SPAC). When in SSB mode, select the correlation time that allows you to hear signals with 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 NR2 is ON, press [NR] (1 s), then turn the MULTI 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.

NOISE BLANKER

Noise Blanker was designed to reduce pulse noise such as that generated by automobile ignitions. Noise Blanker does not function in FM mode.

Press [NB/T/ 7] to toggle the Noise Blanker ON and OFF.

•“NB” appears when the function is ON.

You can further adjust the Noise Blanker level from 1 to 10. The default level is 6.

Press [NB/T/ 7] (1 s), then turn the MULTI control to adjust the Noise Blanker level.

•“NB LV.” and the current level appear on the sub- display.

Note:

◆Noise Blanker is available only for SSB, CW, FSK, and AM modes.

◆Increasing the Noise Blanker level degrades the intermodulation characteristics of the transceiver.

DIGITAL NOISE LIMITER (DNL)

Digital Noise Limiter (DNL) is designed to reduce pulse noise such as that generated by automobile ignitions. Try this function when the Noise Blanker function cannot remove the pulse noises effectively. Digital Noise Limiter does not function in FM mode.

Press [DNL] to toggle the DNL ON and OFF.

•“DNL” appears when the function is ON.

You can further adjust the DNL level from 1 to 3. The default level is 2.

Press [DNL] (1 s), then turn the MULTI control to adjust the Digital Noise Limiter level.

•The current level appear on the sub-display.

Note:

◆Digital Noise Limiter is available only for SSB, CW, FSK, and AM modes.

◆Depending on a pulse type, the DNL function may not be able to remove the noise.

◆Turning the DNL function ON when there is no pulse-type noise and the signal is relatively strong, it could degrade the signal readabilty.

◆When the DNL function is ON, the high-cut filter frequency becomes 3.0 kHz regardless of the DSP filter settings.

◆The DNL function can be used with the Beat Cancel (BC), Noise Reduction (NR) , and Noise Blanker functions at the same time.