User manual YAESU RF UTUNING KIT

[. . . ] Connect the color-coded control cable(s) between the CNTL OUT and CNTL IN jacks (see illustration). If the FT-2000 does not operate and the frequency display blinks sometimes, confirm and correct the "CNTL IN" and "CNTL OUT" connections. The order of connecting multiple RF TUNING KITS is not important. ~AC IN ANT µ-TUNE TO µ-TUNE FROM µ-TUNE RF IN CNTL IN RF Cable (RF µTuning Kit ) RF CABLE(Supplied with RF TUNING KIT) CNTL Cable (Supplied with RF TUNING KIT) CNTL CABLE (RF µTuning Kit ) RF Cable (Supplied with RF TUNING KIT) RF CABLE (RF µTuning Kit ) MULTI CONNECTION ~AC IN ANT RF OUT GND CNTL OUT CNTL OUT CNTL IN CNTL IN Copyright 2006 VERTEX STANDARD CO. , LTD. [. . . ] Top Band Edge You may observe the relative peak point of the -Tune filter in the Tuning Offset Indicator on the display while tuning the Bottom Band Edge [VRF] knob. The amount of change in the center frequency of the -Tune filter, when rotating the [VRF] knob by one click, can be configured using Menu item "035 GEnE T DIAL DIAL. " 035 3. Press the [VRF] button (momentarily) once more to disengage the Tune filter. In this mode, only the fixed bandpass filter for the current band will be engaged. "VRF" icon Tuning Offset Indicator [VRF] button µ-TUNE AND VRF: COMPARISONS TO FIXED BANDPASS FILTERS µ-Tune Inspection of the illustrations to the right will demonstrate the profound advantage of the -Tune circuit. In illustration [A], the gray area represents the passband of a typical fixed bandpass filter covering the 1. 8 ~ 3 MHz range; this is typical of the kind of bandpass filter found in many high-quality HF receivers today. Note also the hypothetical distribution of signals across the 160-meter band. In illustration [B], note the narrow white segment within the gray passband of the fixed BPF. These narrow segments represent the typical bandwidth of the -Tune filter, and one can see that the passband has been reduced from about 750 kHz in the case of the fixed BPF) to a few dozen kHz when -Tune is engaged. The vast majority of the incoming signals are outside the passband of the high-Q -Tune filter, and they will not impinge on any of the RF/IF amplifiers, the mixers, or the DSP. Very strong out-of-band signals like this can cause Intermodulation, blocking, and an elevated noise floor for a receiver. A 1. 8MHz 2. 5MHz FRONT-END BAND WIDTH B 1. 8MHz TUNE BAND WIDTH 2. 5MHz Main Tuning Dial knob [VRF] knob QUICK NOTE The permeability-tuning concept utilized in the -Tune circuit dates back many decades, as it was incorporated in such classic transceivers as the FT-101 and FT-901 series, in addition to the FTDX 401 and similar models. The -Tune circuit in this RF TUNING KIT is the highest development of this circuit concept ever employed in an Amateur transceiver, and is adopted in our highest-grade transceiver FT DX 9000 series. VRF In this example, illustration [a] depicts a typical fixed bandpass filter covering 14. 5 to 22 MHz, and once again the gray shaded area depicts the fixed bandpass filter's frequency coverage. The vertical lines in the illustration represent hypothetical signals throughout this frequency range. Figure [b] shows the same fixed BPF, with the white area representing the typical passband of the VRF filter operating in the same frequency range. Although the selectivity of the VRF is not as tight as that of the -Tune filter, the RF selectivity of the VRF preselector is still magnitudes better than that of the usual fixed bandpass filter, affording significant protection against the ingress of high signal voltage from strong out-of-band signals. a 14. 5MHz 22MHz FRONT-END BAND WIDTH b 14. 5MHz VRF BAND WIDTH 22MHz ADVICE The -Tune filters are the most advanced, selective RF preselector filters ever incorporated into an Amateur Radio transceiver. The RF selectivity provided by -Tune can be of tremendous value in ensuring quiet, intermod-free reception even in the most crowded bands on a contest weekend. [. . . ] To disable -Tune, enter the Menu item "035 GEnE T DIAL of the FT-2000 then DIAL" 035 set the selection to "OFF. " ADVICE With -Tuning, the center frequency of the filter is continuously adjustable throughout its operating range. The quality L/C components ensure high Q of the circuit and a tight passband. The RF preselection design task required the selection of quality L/C components, but the crafting of a tuning mechanism and tuning concept that preserves system Q while providing consistent smooth automated tuning over a wide operating frequency range. [. . . ]