Yaesu Musen 20461X50 Scanning Receiver User Manual FTDX3000 Operating Manual

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

Users Manual 6

Page 45FT DX 3000 OperaTing ManualinTerFerence rejecTiOnµ-tuNe FilteR (ReQuiRes tHe optioNAl RF µtuNiNg Kit)Advice: The µ-Tune lters are the most advanced, selective RF preselector lters ever incorporated into an Amateur Radio transceiver. The RF selectivity provided by µ-Tune can be of tremendous value in ensuring quiet, intermod-free reception even in the most crowded bands on a contest weekend. The µ-Tune lters provide RF selectivity on the order of a few dozen kHz at -6 dB, at the expense of a few dB of system gain on bands where noise gure is seldom an issue. You will notice that the S-meter deection, when µ-Tune is engaged, is slightly less than when it is out of the circuit; this is normal. If your antenna system gain is so low that you cannot hear the band noise when µ-Tune is engaged (highly unlikely), just switch it out, to eliminate the slight insertion loss. As you tune around on an amateur band with µ-Tune engaged, the microprocessor automatically commands the stepper motor driving the toroid core stack to center the lter on your current operating frequency. You may, how-ever, use the [SELECT(µ-TUNE)] knob to skew the lter response to one side or the other from your operating fre-quency, to deal with heavy interference on one side. To re-center the µ-Tune lter on your operating frequency, and eliminate any offset, press the [CLEAR] button.ChangingtheTuningOffsetIndicator1. Press and hold in the [MENU] button for one second to engage the Menu mode.2. Rotate the [CLAR/VFO-B] knob or p/q button to select Menu item “011 DISPLAY BAR DIS-PLAY SELECT”.3. Rotate the [CLAR/VFO-B] knob or p/q but-ton to select “uTUNE (µ-Tune)” (replacing the default “CW TUNE (CW TUNING)” selection).4. Press the [SELECT] button, then press the [MENU] button to lock in the new setting and exit to normal operation.[MENU] Button1. Connect the external equipment between the µ TO and µ FROM jacks on the rear panel.2. Press the [MHz/µT] button, then press the [CLAR/VFO-B] knob. The receive signal will pass through the external equipment. In this case, the “ ” and “ ” icons will be shown in the FLT column of the VFD display Block Diagram.3. Press the [MHz/µT] button again, the receive signal will bypass the external equipment and be applied directly to the transceiver front-end circuit.Advice: Alternate presses of the [MHz/µT] button, will switch the receive signal between the external equip-ment or the direct front-end receive circuit.[MHz/µT] Button[SELECT] KnobAdviceIf you want to use an external bandpass lter or preamplier, you may connect it between the µ TO and µ FROM jacks on the rear panel.Important notIce!When [µ-TUNE] is enabled, the FT DX 3000 cannot receive a signal without an external device of jumper cable between the µ TO and µ FROM jacks.[CLAR/VFO-B] KnobFCC ID: K6620461X50 / IC: 511B-20461X50
Page 46 FT DX 3000 OperaTing Manualipo (iNteRcept poiNt optiMizAtioN)The IPO feature allows the operator to optimize the characteristics of the receiver front end, depending on the current noise level and the strength of incoming signals.Press the [IPO] button several times to set the desired characteristic of the receiver front end, according to the chart below.AMP1: Amplies the incoming signals, using a low distortion RF preamplier (gain: approx. 10 dB).AMP2: Amplifies the incoming signals, using a 2-stage low-distortion RF preamplier (total gain: approx. 17 dB).IPO: Bypasses the RF preamplier, yielding direct feed to the rst mixer.The selected receiver RF preamplier will be indicated in the IPO column of the Block Diagram Display on the display.Advice: The IPO selection will be memorized independently on each VFO stack of VFO-A and VFO-B. On the 10 MHz and lower bands, it generally is not necessary to use any preamplier at all; selecting the “IPO ON” position as described above will increase the strong-signal-handling capability of the receiver, and generally will result in more pleasant reception due to reduced noise. If you can hear band noise with the preampliers disengaged, then a preamplier is generally not needed.Note:The IPO feature is always on “IPO ON” (No RF pream-plier) between 30 kHz and 1.7 MHz.inTerFerence rejecTiOn[IPO] ButtonFCC ID: K6620461X50 / IC: 511B-20461X50
Page 47FT DX 3000 OperaTing ManualinTerFerence rejecTiOnR.Flt (RooFiNg FilteRs)Narrow-band Roong Filters of 15 kHz, 6 kHz, and 3 kHz bandwidths are provided in the rst IF, right after the rst mixer. These lters provide protection for the 2nd mixer, DSP, and other circuitry that follow and can dramatically im-prove reception on a very crowded band (during a contest, etc.). Typically, the AUTO selection mode is satisfactory for most operating situations, but in an extremely crowded phone band you may wish to select, for example, the 3 kHz roof-ing lter for SSB operation.Press the [R.FLT] button to toggle the Roofing Filter selection.AUTO  15 kHz  6 kHz  3 kHz  AUTO .....Advice: As you repeatedly press the [R.FLT] button, you will observe changes in the notation in the R.FLT column of the Block Diagram Display on the display, denot-ing the Roong Filter currently in use. Typically, this selection will be set to “AUTO.” The Roong Filter selection will be memorized inde-pendently on each VFO stack of VFO-A and VFO-B.QuicK poiNt:The “AUTO” selection of the Roong Filter is based on the operating mode. However, you may override the au-tomatic selection, if band conditions warrant a different (usually, a tighter) selection.[R.FLT] ButtonteRMiNology:A “Roong Filter,” as its name implies, places a “Roof” over the receiver’s IF system bandwidth. This “Roof” protects the circuitry downstream from the first mixer from interference, just as a roof on a house protects the contents from rain and snow.FCC ID: K6620461X50 / IC: 511B-20461X50
Page 48 FT DX 3000 OperaTing ManualiF Noise blANKeR (Nb) opeRAtioNThe FT DX 3000 includes an effective IF Noise Blanker, which can signicantly reduce noise caused by automotive ig-nition systems.1. Press the [NB] button briey to reduce short dura-tion pulse noise such as from switching transients, automobile ignitions and power lines. The “NB ON” will appear in the display to conrm that the Narrow-NB is operating.2. Press the [NB] button again to reduce longer-dura-tion man-made pulse noise. The “NBW ON” will appear in the display to conrm that the Wide-NB is operating.2. If desired, you may adjust the Noise Blanker level via Menu item “033 GENERAL NB LEVEL” to the point where the offending noise is best reduced or eliminated. See box below for details.3. To end Noise Blanker operation, press the [NB] but-ton once more. The “NB OFF” will appear in the display, conrming that the Noise Blanker is no lon-ger in operation.Advice:The Noise Blanker operation will be memorized inde-pendently on each VFO stack of VFO-A and VFO-B. However, the Noise Blanker level is in common.AdjustingtheNoiseBlankerLevel1. Press and hold in the [MENU] button for one second to engage the Menu mode.2. Rotate the [CLAR/VFO-B] knob or p/q button to select Menu item “033 GENERAL NB LEVEL”.3. Rotate the [CLAR/VFO-B] knob or p/q but-ton to the point where the offending noise is best reduced or eliminated.4. Press the [SELECT] button, then press the [MENU] button to lock in the new setting and exit to normal operation.inTerFerence rejecTiOn[NB] Button[MENU] Button[CLAR/VFO-B] KnobFCC ID: K6620461X50 / IC: 511B-20461X50

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