Vertex Standard FT-1000MP IPO Intercept Point Optimization, AGC Automatic Gain Control Selection

Page 47

OPERATION

DEALING WITH INTERFERENCE

band (for example, tuning from 1.999.99 MHz to 2.000.00 MHz), the higher gain of the “Flat” preamp will cause the background noise to increase sud- denly (and decrease again if you tune back inside the 160-meter band).

(2)When tuning outside of a high-frequency amateur band (for example, tuning from 28.000.00 MHz to 27.999.99 MHz), the higher gain of the Tuned premap will cause the background noise to de- crease suddenly (and increase again if you tune back inside the 10-meter band).

(3)When operating on the 14 MHz band, the Tuned and Flat preamps have basically identical gains. Very little difference in performance will be observed, inside or outside the 20-meter band.

IPO (Intercept Point Optimization)

Normally, the front-end FET RF amplifiers provide maximum sensitivity for weak signals. During typical conditions on lower frequencies (such as strong overloading from signals on adjacent frequencies), the RF amplifiers can be bypassed by pressing the [IPO] button so the green LED is on. This improves the dy- namic range and IMD (intermodulation distortion) char- acteristics of the receiver, at a slight reduction of sen- sitivity. On frequencies below about 10 MHz, you gen- erally will want to keep the [IPO] button engaged, as the preamplifiers are usually not needed at these fre- quencies.

ATT (RF Attenuator) Even with the IPO function on, ex-

tremely strong local signals can still de- grade reception. So if you still notice the effects of overloading, or if the signals you want to listen to are very strong, you

can use the ATT selector to insert 6, 12, or 18-dB of RF attenuation in front of the RF amplifier. If background noise causes the S-meter to deflect on clear channels, turn the ATT selector clockwise until the S-meter drops to about S-1 (the white area at the left end of the top meter scale). This setting optimizes the trade-off be- tween sensitivity and interference immunity. Also, once you have tuned in a station you want to work, you may want to reduce sensitivity further (or add more attenu- ation) by turning the ATT control to a more clockwise setting. This reduces the strength of all signals (and noise) and can make reception more comfortable, im- portant especially during long QSOs.

When looking for weak signals on a quiet band you will want maximum sensitivity, so the IPO should be disabled and the ATT selector should be set to “0.” This situation is typical during quiet times on frequen- cies above 21 MHz, and when using a small or nega- tive-gain receiving antenna on other bands.

AGC (AUTOMATIC GAIN CONTROL) SELECTION

When tuning around the band look-

ing for signals, the AGC selector is usu-

ally best kept in the “AUTO” position, where AGC decay is automatically se- lected according to the operating

mode. You can manually select re-

ceiver AGC; however, a few points about AGC and re- ceiver recovery time need to be pointed out.

For SSB reception, the “FAST” position allows the receiver gain to recover quickly after tuning past strong signals or when fast fading occurs. However, once you have a station tuned in, reception will usually be more comfortable if you switch to the “SLOW” position (keep- ing the receiver from picking up low-level noise during pauses in speech).

For CW reception, when several signals are present in the passband, the “FAST” position can avoid AGC “pumping” (gain fluctuations) caused by strong undesired signals.

For AM reception, the “SLOW” position is usually better, and for 300-baud packet and RTTY/AMTOR, the “FAST” or “OFF” positions will usually give the few- est errors/retries.

RF GAIN SETTING

When tuned to a moderate strength signal, if low level background noise is still present after setting the ATT selector, try reducing the RF GAIN control from the fully clockwise position. This reduces the signal input to the first mixer via a PIN diode attenuator and causes the minimum S-meter reading to move up he scale, often clearing up the background noise and put- ting the desired signal more “in the clear.” Remember, however, to return this control fully clockwise when you want to receive weak signals, or read low levels on the S-meter. Also read the box on this page.

Note on AGC

The AGC “OFF” position disables the overload-pro- tection normally provided by the AGC circuitry. If the RF GAIN control is left fully clockwise in this condition, the RF and IF amplifiers can be easily overloaded (causing distortion) when a strong sig- nal is received. Correct the overload either by set- ting the AGC selector to another position, or by turning the RF GAIN control counterclockwise to set receiver gain to a comfortable level.

MARK-V FT-1000MP Operating Manual

page 45

Image 47
Contents Yaesu Europe B.V Vertex StandardTabel of Contents MARK-V FT-1000MP Operating Manual General DescriptionMARK-V FT-1000MP Operating Manual Receiver SpecificationsGeneral TransmitterPLUG/CONNECTOR Pinout Diagrams Supplied Accessories Accessories & OptionsAvailable Options If Crystal Filter OptionsOptional Main Receiver Filters Optional Sub Receiver FilterGround Connections Safety PrecautionsPower Connections RF Field Exposure Advisory & Electromagnetic Compatibility Antenna PrecautionsElectrical Shock Prevention Transceiver Location General SetupFP-29 Preliminary InspectionRG-8X Adjusting the Front FeetMemory Backup Antenna ConsiderationsOperation with QSK Amplifiers Accessory InstallationLinear Amplifier Interfacing QSKOperation with NON-QSK Amplifiers FL-2100SERIES or Others About ALC Transverter Operation Digital Modes with a TNC Or Computer Sound Card PSK-31 Digital Modem TNC, WEATHERFAX, ETC. InterfacingMARK-V FT-1000MP TNC Accessory Installation Accessory Installation CW KEY/PADDLE and Computer Keying Interface Suggestions FeaturesConfiguration Suggestions Other DIGITAL/RECORDING Device InterfacingAntenna Connections Large Receive AntennasPersonal Computer Interfacing for Contest SOFTWARE, ETC Front Panel Controls Moni Knob AF Gain RF Gain KnobRF PWR Knob SUB AF KnobFast Button Mode Selection ButtonsEdsp Filters CLASS-A ButtonAF REV Button Main VFO-A Tuning KnobMain VFO-A RX & TX Switch-LED Shuttle Jog and VRF & Idbt ButtonsBand Keypad VFO & Memory ControlCW and Electronic Keyer Controls SUB VFO-B RX & TX Switch-LEDLock Button SUB SQL Knob2nd and 3rd if Filter Bandwidth NOR NAR ModeBandwidth Buttons NOR/NAR1/NAR2 Buttons NB ButtonVRF/MEM CH Knob Sequence VRF IndicatorTuner Button VRF/MEM CH KnobLCD Bargraph Meter Indications HI SWR Sub Receiver ModeMEM F WaitTOP Panel Access & Controls Additional Note PKTRtty 12. CWPacket DIN Jack Rear Panel Controls & ConnectorsRemote Jack CW Sidetone TrimmerDC in Jack Band Data DIN JackMenu Programming OperationKey Beeper Before StartingMode Selection Special Note for CW Mode Reverse CW sidebandVRF/MEM CH VFO KnobShuttle Jog Fast Button OperationVFO Channel Stepping Display SettingsPanel Up/Down Buttons Microphone Up/Dwn ButtonsKeypad Frequency Entry Alternate VFO Operation Front & RearevfoToggle VFOs VFO Selection & Receiver MutingRTTY/PKT Tuning Signal Tuning Meter IndicationsCW Tuning AM Synchronous Tuning SUB-DISPLAY Mode Selection Expanded Tuning ScaleAM Synchronous Tuning Meter Frequency Band Range MHz AM Broadcast ReceptionGeneral Coverage Reception VRF Variable RF FRONT-END Filter Receiver Front End Configuration For illustrative purposesWide Band and Tuned Preamp Selection Dealing with InterferenceAGC Automatic Gain Control Selection RF Gain SettingIPO Intercept Point Optimization If Filter Bandwidth Selection There are two banks of select Main receiver VFO-A if Bandwidth Filter SelectionNoise Blanker Width Control Width Action Using Width control to reduce QRMNotch Filter SHIFT/WIDTH Tuning StepsUsing if Shift to reduce QRM If Shift ActionClarifier RX/TX Offset Tuning Advice on QRM ReductionOffset Display Mode Clarifier SettingsSelecting Antennas TransmittingAntenna Selection Band TX RangeSSB Transmission Important NoteTransmitter Monitor Carrier Point Offset Microphone Tone SelectionRF Speech Processor Class-A OperationCW Transmission VOX Operation Voice-Actuated T/R Switching OperationStraight-Key Operation CW Straight Key and Paddle Connections Electronic Keyer OperationACS Auto Character Spacing CW Pitch Setting and Spot Tone Keyer SettingsAM Transmission Digital Mode OperationRtty Operation Baud PacketTNC Tone Pair Tone Center Frequency Packet OperationBaud FM Packet FM Transmission FM Repeater OperationDual Reception Main and Sub VFO AudioHeadphone Audio Adjustments Using Headphones for Dual ReceiveSplit Frequency Operation Split Operation ModeSUB VFO-B Settings VFO Tracking Sideband Diversity ReceptionBandwidth Diversity Reception Memory Structure Memory FeaturesMemory Programming Basic Memory Storage ProcedureAuto Channel-Up Regarding the VRF/MEM CH KnobMemory Checking Memory TuningRecalling & Operating on Memory Channels Copying Between Memories Limiting Memory Group OperationCopying a Selected Memory to VFO-A Grouping Memories QMB Quick Memory Bank Operation Memory Scan Skip Auto Memory WriteVFO Scanning Memory ScanningMemory Masking Scan Resume ModeScan Skip Disable Programmed Memory Scanning PMS Memories P1 ~ P9 Advanced Features Edsp RX Audio Enhancement Edsp ModulationEdsp Contours Edsp FunctionsEdsp Auto Multiple Notch Action Edsp Noise ReducerEdsp Auto Multiple Notch Filter Important Note About Edsp Contest Keyer Control FeaturesRemote Control Operation IntroductionMessage Storage Contest Number MemoryCQ or ID Memory User Message Memories 1Contest Keyer Operation Tune ModeII. VFO/MEMORY Control III. Main VFO-A ControlSub VFO B Dial Main VFO a Dial USER-CUSTOMIZED Operating ModeOverview CommentsDVS-2 Controls No Function Segment Message Recording PlaybackMessage Recording SegmentMessage Monitor Receiver Recording withSelecting Receiver Audio Message TransmissionOperation Phone Patch OperationPacket Tuning Tuning Meter RE-CALIBRATIONCAT Data Byte Format CAT 5-BYTE Command StructureOverview CAT Data Protocol Opcode0A H Constructing and Sending CAT Commands50 H 03 H 00 H 81 H 09 H DATA/ARGUMENT BytesMemory Channel Data Byte Status Update Data OrganizationDownloading Status Flags Bytes 1~Status Flag Byte #5 Contents Status Flag Byte #1 ContentsStatus Flag Byte #4 Contents Status Flag Byte #2 ContentsMemory Channel Data Hex Codes Byte Data Record Structure Rtty PKT Coding Examples 0EH Opcode Command Chart0AH 0CH75H Command Parameter Bytes Opcode Or Key 1st 2rd 3rd 4th 5th70H Edsp8CH RPT8AH VFOByte Format F = 00H Byte Format F = 01H FAHGrP4-cH GrP1-cHGrP2-cH GrP3-cHSJ-SPEEd Auto-uPEdSP DiAL-SPdNotcH Auto-inScAn-ALL Sc-dL-tiBEEP-F SP-HoLdNot Used RF out BEEPFiL CW norDAtAnAr2 Sub-FiLRPt-SHFt PAc-tonENot Used CtcSS TonE SEtPA-cnt Rc-FuncFASt-SEt Lock-SELCAr oFSt USEr-SEtSub-AGc TunEr1st Fc = F + 70.455 BFO kHz Custom Frequency & Display Offset InformationPKT-F User KHz 500 Hz 250 HzFunc No Function Setting Range Default Menu Selection Setting TableNORMAL/REVERSE Normal Main VFO-A/SUB VFO-BMONO/STEREO 1/STEREO Stereo SEPARATE/BALANCE SeparateLSB USB CW USB CW LSB Rtty LSB Rtty USB PKT LSB Default User Function SettingsTX PLL Easy Set Mode SettingsRX PLL TCXO-6 Installation Installing Internal AccessoriesSUB Receiver CW Narrow Filter Filter InstallationInstallation Main Receiver 2ND and 3RD if FiltersMemory BACK-UP Switch Lithium Battery ReplacementInternal 13.8V Fuse Replacement POWER-ON Microprocessor Reset Procedures MARK-V FT-1000MP Operating Manual