Yaesu FT-897 Operating Manual

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Yaesu FT-897 Operating Manual Manual pdf 27 page image

Page 25FT-897 OPERATING MANUALRECEIVER ACCESSORIESNOISE B LANKERThe IF Noise Blanker may be useful in reducing or elimi-nating some types of impulse noise, especially noise gener-ated by automotive ignition systems.1. Press the [F] key momentarily, then rotate the MEM/VFO CH knob, as needed, until Multi Function Row “l”[NB, AGC, OFF] appears on the display.2. Press the [A](NB) key to activate the Noise Blanker. Pa-rentheses will appear on both sides of the “NB” selec-tion, indicating that the Noise Blanker is now on.3. To adjust the blanking level, press and hold in the[A](NB) key for one second. This instantly activatesMenu Mode No-063 [NB LEVEL], which allows adjust-ment of Noise Blanking Level. Rotate the DIAL knob toset a higher or lower blanking level (on a scale of 0 to100). When done, press and hold in the [F] key for onesecond to save the new setting and return to normal op-eration.4. Press the [A](NB) key again to turn the Noise Blankeroff.IPO (INTERCEPT POINT OPTIMIZATION)The IPO feature bypasses the receiver RF preamplifier,thereby eliminating the preamp’s gain. This feature is notavailable on the 144 MHz and 430 MHz bands.1. Press the [F] key momentarily, then rotate the MEM/VFO CH knob, as needed, until Multi Function Row“m” [IPO, ATT, NAR] appears on the display.2. Press the [A](IPO) key to bypass the receiver input pream-plifier. Parentheses will appear on both sides of the “IPO”selection, and the “ ” icon will appear on the display.indicating that the preamp is now disengaged from thereceiver circuit.3. Press the [A](IPO) key once more to re-activate thepreamp.On the bands below 14 MHz, the input pream-plifier is rarely necessary, and activation of theIPO feature will provide substantial protectionagainst intermodulation and other problems associatedwith strong signal input to the receiver. Rule of thumb: solong as the S-meter is moving on background noise, addi-tional front-end gain is not necessary.ATT (FRONT END ATTENUATOR)The Attenuator will reduce all signals (and noise) by 10 dB,and it may be used to make reception more pleasant underextremely noisy conditions. This feature is not available onthe 144 MHz and 430 MHz bands.1. Press the [F] key momentarily, then rotate the MEM/VFO CH knob, as needed, until Multi Function Row“m” [IPO, ATT, NAR] appears on the display.2. Press the [B](ATT) key to activate the Attenuator. Pa-rentheses will appear on both sides of the “ATT” selec-tion, and the “ ” icon will appear on the display.3. Press the [B](ATT) key once more to switch the Attenu-ator out of the receiver front end circuit. Signals willagain be received at a level 10 dB louder than was thecase when the Attenuator was engaged.DSP B ANDPASS F ILTERIn the SSB mode, the receiver’s selectivity may be enhancedvia the DSP Bandpass Filter.1. Press the [DSP] key momentarily. This instantly acti-vates Multi Function Row “p” [DNR, DNF, DBF].2. Press the [C](DBF) key to activate the DSP BandpassFilter. Parentheses will appear on both sides of the “DBF”selection, and the “DSP” will appear at the center topon the display. You will notice a decrease in both back-ground noise and interference, if any is present.3. The bandwidth of the DSP filter may be modified, tocustomize the bandwidth to your operating needs. Toadjust the Low-Cut and High-Cut characteristics of theDSP Bandpass Filter:• Press and hold in the [C](DBF) key for one second.This instantly activates Menu Mode No-047 [DSPLPF CUTOFF], which allows adjustment of the High-Cut (Low-Pass) filter.• Turn the DIAL, as desired, to adjust the high-fre-quency cutoff of the DSP Bandpass Filter.• Now rotate the MEM/VFO CH knob one clickcounter-clockwise to select Menu Mode No-047[DSP HPF CUTOFF], which allows adjustment of theLow-Cut (High-Pass) filter.• Turn the DIAL, as desired, to adjust the low-frequencycutoff of the DSP Bandpass Filter.• When done, press and hold the [F] key for one sec-ond to save the new setting(s) and return to normaloperation.4. Press the [C](DBF) key once more to disable the DSPBandpass Filter.HPF100 Hz~1000 Hz LPF1000 Hz~6000 Hz