Yaesu FT-847 Operating Manual

Also see for FT-847: Technical supplement Technical supplement Technical supplement Modification

Contents

41FT-847 OPERATING MANUALOPERATIONRECEIVER FEATURESNOTCH FILTER (DSP)Unwanted beat notes within the receiver’s IF filterpassband can be effectively removed by utilization ofthe DSP NOTCH function. The DSP system will detectthe incoming carrier, then automatically center a sharpnotch filter to eliminate the beat note. If multiple beatnotes are present, the DSP will create multiple notchfilters to eliminate them.To activate the DSP NOTCH filter, press the[D. NOTCH] switch; the “NOTCH ” iconwill appear on the display. To turn this fil-ter off, press the [D. NOTCH] switch again.Note: The DSP NOTCH filter should not beused in the CW mode! The DSP system will in-terpret a CW carrier as being “interference,”and will notch out the incoming signal. There-fore, as you tune the CW portion of the bandwith the NOTCH filter on, CW signals will ap-pear for a moment, then disappear as they arenotched out.CW REVERSEWhile operating on CW, occasionally you may encoun-ter interference situations which cannot be resolvedby switching to a narrower filter or by adjustment ofthe IF SHIFT control. And there sometimes are operat-ing situations requiring a mode change from, for ex-ample, LSB to CW; if the wrong “sideband” is uti-lized in the CW mode, the other station may not beeasy to find.The FT-847 can be quickly configured, so as to avoidthese problems, to utilize either “USB” or “LSB” car-rier injection in the CW mode. To do this, while in theCW mode, just press the [CW] switch momentarily.The “CW ” icon glows steadily for USB-side injec-tion, while the “ L S B ” icon will appear to the left ofthe “CW ” icon for LSB injection. This system allowsinstantaneous recognition of the current injection modeselected for CW use.Referring to example A, note thepresence of both a desired signaland interfering signal. By switch-ing sidebands (example B), notehow the interfering signal has beenavoided through selection of theopposite sideband.Note: W h e n s i d e b a n d s a r eswitched, all aspects of CWoperation are switched atonce, including the trans-mitted CW carrier and the displayed frequency.This avoids the necessity of making multiple ad-justments so as to align the receiver and trans-mitter sections for proper operation.