Yaesu Musen 20461X50 Scanning Receiver User Manual FTDX3000 Operating Manual

Yaesu Musen Co., Ltd. Scanning Receiver FTDX3000 Operating Manual

Users Manual 7

Page 49FT DX 3000 OperaTing ManualinTerFerence rejecTiOncoNtouR coNtRol opeRAtioNThe Contour ltering system provides a gentle perturbation of the IF lter passband. The Contour is set to either sup-press, or boost specic frequency components, and thus enhance the sound and readability of a received signal.1. Press the [CONT/APF] button to activate the Con-tour lter. The LED inside the [CONT/APF] button glows orange and the current “null” (or “peak”) po-sition of the Contour lter will appear in the CON-TOUR indicator on the display.2. Rotate the [CONT/APF] knob to achieve the most natural-sounding audio reproduction on the incom-ing signal.Advice: The display will show the Contour frequency for 3 seconds whenever the [CONT/APF] knob is turned.3. To cancel Contour tuning, press the [CONT/APF] button momentarily.Advice: Alternate presses of the [CONT/APF] button, will switch the Contour lter between on or off.Advice: The Contour lter selection will be memorized inde-pendently on each VFO stack of VFO-A and VFO-B. The Contour lter level (either a null or a peak) may be adjusted using Menu item “109 RX DSP CON-TOUR LEVEL”. The factory default setting is for a null of –15 (dB). The bandwidth over which the Contour lter effect is applied may be adjusted using Menu item “110 RX DSP CONTOUR WIDTH”. The factory default setting is 10. When the optional DMU-2000 Data Management Unit is connected, the Audio Scope (on the “Oscil-loscope” page) is particularly useful when adjusting the Contour control. Not only can you see the effect of the null/peak of the Contour system, but you also can see the position of the null/peak with respect to frequency components of interest on the incoming signal. You may then observe (on the Audio Scope) the effect of the Contour control while listening to the effect on the signal, and this will help build your intuition on how best to use Contour tuning in the future.Refer to Figure “B”, this illustrates an “indenta-tion” of the Contour filter in the center of the passband. The Contour lter is placing a low-Q “notch” (per the setting of Menu item “069 RGEN CNTR LV”, referenced above) in the pass-band. Counter-clockwise rotation (to the left) of the [CLAR/VFO-B] knob causes the notch to move towered a lower frequency within the passband, while clockwise rotation (to the right) causes the notch to move toward a higher fre-quency within the passband. By removing inter-ference or unwanted frequency components of the incoming signal, it is possible to make the desired signal rise out of the background noise/interference, enhancing intelligibility.QuicK poiNt:The steep slopes of the DSP ltering, when adjusted aggressively, can impart an unnatural sound to an incoming sig-nal. Often, a narrow bandwidth is not the key to improving copy; the incoming signal itself may have undesirable or excessive frequency components, especially in the low frequency range around 100-400 Hz. By judicious use of the Contour lter, the “shoulder” of the passband response may be altered, or components may be removed from within the passband, allowing the desired signal to rise above the background noise and interference in a manner not obtainable with other ltering systems.[CONT/APF] Button[CONT/APF] Knob A B CFCC ID: K6620461X50 / IC: 511B-20461X50
Page 50 FT DX 3000 OperaTing ManualinTerFerence rejecTiOniF sHiFt opeRAtioN (ssb/cw/Rtty/pKt/AM Modes)IF SHIFT allows you to move the DSP lter passband higher or lower, without changing the pitch of the incoming sig-nal, and thus reduce or eliminate interference. Because the carrier tuning frequency is not varied, there is no need to re-tune the operating frequency to eliminate the interference. The total passband tuning range for the IF SHIFT system is ±1 kHz.1. Rotate the [SHIFT] knob to the left or right to re-duce the interference.Advice: The display will show the shift value of the IF SHIFT for 3 seconds whenever the [SHIFT] knob is turned.Advice:The center position of the IF passband will be memo-rized independently on each VFO stack of VFO-A and VFO-B.Referring to Figure “A”, note the depiction of the IF DSP lter as the thick line, with the [SHIFT] knob in the 12 o’clock position. In Figure “B”, an interfering signal has appeared inside the original passband. In Figure “C”, you can see the effect of rotating the [SHIFT] knob. The interference level is reduced by moving the lter passband so that the interference is outside of the passband.[SHIFT] Knob A B CFCC ID: K6620461X50 / IC: 511B-20461X50
Page 51FT DX 3000 OperaTing ManualinTerFerence rejecTiOnwidtH (iF dsp bANdwidtH) tuNiNg (ssb/cw/Rtty/pKt Modes)The IF WIDTH tuning system allows you to vary the width of the DSP IF passband, to reduce or eliminate interference. Moreover, the bandwidth may actually be expanded from its default setting, should you wish to enhance incoming sig-nal delity when interference on the band is low.1. Rotate the [WIDTH] knob to the left or right to re-duce the interference.Advice: The frequency display will show the bandwidth of the IF passband for 3 seconds whenever the [WIDTH] knob is turned.[WIDTH] KnobAdvice:The IF Bandwidth will be memorized independently on each VFO stack of VFO-A and VFO-B.Referring to Figure “B”, you can see the default bandwidth on the SSB mode.By rotating the [WIDTH] knob to the left, the bandwidth will narrow (see Figure “A”, while rotation of the [WIDTH] knob to the right, as depicted in Figure “C”, will increase the band-width. A B CThe default bandwidths, and total bandwidth ad-justment range, will vary according to the operat-ing mode:SSB Mode: 1.8 kHz ~ 4.0 kHz (default: 2.4 kHz).CW Mode: 500 Hz ~ 2.4 kHz (default: 2.4 kHz)RTTY/PKT Modes: 500 Hz ~ 2.4 kHz (default: 500 Hz)UsingIFSHIFTandWIDTHTogetherThe IF SHIFT and Variable IF WIDTH features together form a very effective interference-ght-ing ltering system.For example, in Figure “A”, you can see how in-terference has appeared both on the high and low sides of the desired signal. Rotate the [WIDTH] knob, the interference from one side can be eliminated (Figure “B”). Next, rotate the [SHIFT] knob to re-positioning the passband (Figure “C”), the interference on the opposite side can be re-moved, without re-introducing the interference previously eliminated in Figure “B”. A B CAdvice: For best interference reduction, the WIDTH and SHIFT features are the primary tools you should use. After narrowing the bandwidth (WIDTH) and/or adjusting the center of the passband (SHIFT). The Contour control may then yield additional signal-enhancement benefits on the net residual bandwidth. Even more, the IF NOTCH Filter (described later) may also be used, in conjunction with these lter systems, to signicant advantage.FCC ID: K6620461X50 / IC: 511B-20461X50
Page 52 FT DX 3000 OperaTing ManualinTerFerence rejecTiOnNARRow (NAR) oNe-toucH iF FilteR selectioNPressing the [NAR] button provides one-touch, mode-specic, selection of a narrow IF DSP lter setting that does not require resetting the [WIDTH] knob.Pressing the [NAR] button once more returns the band-width control to the WITDH/SHIFT system. The factory default bandwidths are:: Depends on the [WIDTH] knob( ): Default BandwidthopeRAtiNg Mode SSB CW RTTY/PKT-L/PKT-U PKT-FMAMFM (28/50 MHz Bands) “oN”200 Hz ~ 1.8 kHz(1.5 kHz)100 ~ 500 Hz(500 Hz)100 ~ 500 Hz(300 Hz)9 kHz6 kHz9 kHz “oFF”1.8 ~ 4.0 kHz(2.4 kHz)500 Hz ~ 2.4 kHz(2.4 kHz)500 Hz ~ 2.4 kHz(500 Hz)16 kHz9 kHz16 kHz[NAR] switcHAdvice: When the narrow bandwidth is selected, the “ ” icon will appear in the display. Even if the [NAR] button has been pressed to en-gage the narrow lter, you may adjust the narrow IF bandwidth by rotating the [WIDTH] knob. The IF SHIFT still is operational. For many applications, you may nd that simply pressing the [NAR] button instead of adjustment of the [WIDTH] knob, may be satisfactory for interference reduction. When you press the [NAR] button in the FM mode, both transmit and receive bandwidths are narrowed.[NAR] ButtonFCC ID: K6620461X50 / IC: 511B-20461X50
Page 53FT DX 3000 OperaTing ManualinTerFerence rejecTiOniF NotcH FilteR opeRAtioN (ssb/cw/Rtty/pKt/AM Modes)The IF NOTCH lter is a highly effective system that allows you to slice out an interfering beat note or other carrier signal from inside the receiver passband.1. Press the [NOTCH] button to activate the Notch l-ter. The LED inside the [NOTCH] button glows or-ange and the current “null” position of the NOTCH filter will appear in the NOTCH indicator on the display. The [NOTCH] knob functions as the Notch adjustment knob.2. Rotate the [NOTCH] knob to adjust the “null” posi-tion of the Notch lter.Advice: The frequency display will show the Notch frequen-cy for 3 seconds whenever the [NOTCH] knob is turned.3. To cancel the NOTCH filter, press the [NOTCH] button momentarily. The graphic disappears from the NOTCH indicator on the display, conrming that the NOTCH lter is no longer operation.Advice: Alternate presses of the [NOTCH] button, will switch the NOTCH lter between on or off.Advice: The IF NOTCH Filter selection will be memorized independently on each VFO stack of VFO-A and VFO-B. When the optional DMU-2000 Data Management Unit is connected, the effect of the IF NOTCH lter may be observed on the Audio Scope (on the “Os-cilloscope” page). The Notch will be observed as a “dip” in the noise platform observed. What’s more, the “Waterfall” display may be used to observe the effect of the IF NOTCH lter, which will appear as a white area in the colored background area.[NOTCH] ButtonThe performance of the IF NOTCH filter is shown in Figure “A”, where the effect of rotation of the [NOTCH] knob is depicted. In Figure “B” you can see the notching effect of the IF NOTCH lter as you rotate the [NOTCH] knob to elimi-nate the incoming interference. A BFCC ID: K6620461X50 / IC: 511B-20461X50

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