EFJohnson 7780 service manual Transmitter Performance Tests, Power Output, Transmit Frequency

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ALIGNMENT PROCEDURE AND PERFORMANCE TESTS

6.9 TRANSMITTER PERFORMANCE TESTS

6.9.1 POWER OUTPUT

Refer to Section 6.8.1 for information on test channels. Proceed as follows:

1.Connect a wattmeter and dummy load to the antenna jack as described in Section 6.1.2.

2.Key the transmitter and high power output should be 2.8-3.5 watts. Check channels on both ends of the band.

3.Select the talk-around mode by pressing the Talk- Around option switch. The talk-around mode is

indicated by in the display. Key the transmitter and power output should be 2.5 watts or greater. Check channels on both ends of the band.

4.Select the low power mode by pressing the High/ Low Power option switch. Low power is indicated by “LOW” in the lower part of the display. Power output should be 0.8-1.2 watt in the standard mode and 0.7-1.2 watt in the talk-around mode.

6.9.2 TRANSMIT FREQUENCY

Monitor the transmit frequency with a communi- cation monitor set to the channel frequency. At room temperature, the frequency should be within ± 400 Hz. This also checks the receive frequency.

6.9.3 TRANSMIT MODULATION

1.Select a channel not programmed for Call Guard (CTCSS/DCS) squelch and monitor the transmit signal with a communication monitor. Speak into the microphone with a normal voice and modulation should be approximately 3.4 kHz (wideband) or 1.4 kHz (narrow band).

2.Select a channel programmed for Call Guard squelch and with no voice or other microphone input signal, data deviation should be 1.0 kHz (wideband) or 0.8 kHz (narrow band) ± 200 Hz.

3.Speak into the microphone with the channel programmed for Call Guard squelch selected. Maximum total audio and Call Guard deviation should be 4.7 kHz (wideband) or 2.3 kHz (narrow band).

6.9.4 TRANSMITTER CURRENT DRAIN

Maximum current drain in the transmit mode should be as follows:

High Power, Standard Mode - 1.75 A

High Power, Talk-Around Mode - 2.0 A

Low Power, both modes - 1.3 A

	November 1999
6-7	Part No. 001-7780-500

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Contents 7780 Page Page Table of Contents Table of Contents CONT’D List of Figures List of TablesScope of Manual Equipment Description General InformationTransceiver Identification AccessoriesFactory Customer Service Part Number BreakdownFactory Returns AccessoriesAccessory Toll-Free 800Definitions Replacement PartsInternet Home Intrinsically Safe Information Classification of Hazardous Areas and Atmospheres Temperature Code T3CPossible Ignition Sources Intrinsically Safe and Nonincendive RatingsArea Classification Accessing PC BoardsMaterial Classification Typical Hazard Group ClassRemoving Logic Unit Removing RF UnitGeneral SpecificationsControls and Display FeaturesTransceiver Operation Low-Battery Indicator Amber TX Indicator Red Indicates when the transmitter is keyedDisplay DisplayFront Panel Keys Full Keypad Model Backlight Turning Power on and Setting VolumeOption Switches General OperationSee Option Switch FunctionsFunction Conv Scanning Tone ENABLE/DISABLEConventional and SMARTNET/ Smartzone Operation Monitoring Before Transmitting Conventional FeaturesDisplay Mode Selection Call Guard Squelch Monitor ModeBusy Channel Lockout Conventional Mode Scanning Penalty TimerConversation Timer Power Output SelectPriority Channel Sampling Standard Conventional Calls DTMF/ANI SignalingEnhanced Private Conversation Calls SMARTNET/SMARTZONE FeaturesViewing Unit ID Standard Group CallsTransceiver Operation Private Conversation II Calls Telephone Calls Call Alert Sending Status Conditions Emergency Alarm and CallMessaging Dynamic Regrouping Failsoft OperationSMARTNET/SMARTZONE Scanning Supervisory Tones Zone Change Parameter Keypad ProgrammingMenu Description Channel Parameters Channel Change ParameterSystem Parameters Computer Description Programming SetupPctrunk Software Installation Transceiver ProgrammingHelp Files Connecting RPI to Computer and TransceiverStarting and Exiting Programming File TypesCreating and Displaying Systems Screen Pop-Up Buttons and File Size IndicatorProgramming Procedure File Size IndicationMenu Bar Menu CommandsWindow Menu Radio Type MenuDownload Menu Upload Menu Systems MenuZones DefaultsRADIO-WIDE Parameter Screens BandAssign Function Buttons Radio Wide Scan ListRadio-Wide Scan List Screen Modify List ScreenHot Dtmf RADIO-WIDE Conventional ScreenRADIO-WIDE SMARTNET/SMARTZONE Screen Full Spectrum CC ScanConventional System General Screen Adjustable ParametersRADIO-WIDE Portable Options Screen Programming Conventional Systems and ChannelsScan List Button TimersConventional System Modify Scan List Screen Keypad EditingPriority Channel Selection Scan TimersSetting UP Conventional Channels Selected Channel Conventional Channel Screen ParametersTx Time-Out Transmit PowerSignaling Channel TypeSplinter Channels Restricted AccessTime-Out Timer ISW Delay TimePrivate Call SMARTNET/SMARTZONE System Other ID’S ScreenSMARTNET/SMARTZONE System Phone Interconnect Screen Phone InterconnectFailsoft Channel SMARTNET/SMARTZONE System Emergency Settings ScreenEmergency Alarm SMARTNET/SMARTZONE System Talk Groups ScreenMessage Aliasing Screen SMARTNET/SMARTZONE System Lists ScreensTrunking Phone List Screen Control Channels Screen Announcement Groups ScreenTrunking Call List Screen SMARTNET/SMARTZONE Channel Screen Parameters Setting UP SMARTNET/SMART- Zone ChannelsStatus Aliasing Screen Other Screen Parameters SMARTNET/SmartZone Channel ScreenRecommended Tone Call Guard Codes Freq Call Guard CTCSS/DCS Codes and TonesMHz Channels MHz Channels MHz Channels MHz Channels MHz Channels MHz Channels Synthesizer Description Power Switching and RegulationPower Switching Circuit DescriptionCharge Pump Q1, Q2, Loop Filter VCO and Tcxo ModulationSynthesizer Chip IC1 If Amplifier Q2, LIMITER/DETECTOR IC3 Receiver Circuit DescriptionRF Amplifier Q1, First Mixer Q2 Amplifier Q9, Driver Q8 Antenna Switch and LOW-PASS FilterSquelch Circuit IC4A/B, IC5A Transmitter DescriptionReceive Audio Processing Control Logic and DisplayPin Port Name Input or Description Active High Output Microprocessor IC306 Pin DescriptionsHvfulswlrq Receive Data FILTER/DETECTOR IC102A/B, IC107A/B Audio Amplifier IC104-IC106Receive and Transmit Data Processing Transmit Audio Processing Transmit Data Filter IC206B/ IC206ASmartnet Data Processing LOW-PASS Filter IC205A/BFunction Fahrenheit Celsius Battery Pack and Charger InformationBattery Pack Power Setting Operating TimeBattery Pack and Charger Information Test Setup Alignment Procedure and Performance TestsMm/3/32 Mm/1/8 Phone Jack Tune Software HqhudoMain Pctune Screen Preliminary SetupModulation Balance Transmit Frequency and PowerTransmit Power Adjustment Screen High Power Level = 3.0 watts Low Power Level = 1.0 wattData Deviation Squelch AdjustRssi Adjust Audio DeviationReceiver Performance Tests Performance TestsTransmit Modulation Power OutputTransmitter Performance Tests Transmit FrequencyThis page intentionally left blank Ref No Description Parts ListDisplay Assembly Chassis PartsDisplay Assembly KEY AssemblyIf Assembly If AssemblyKEY Assembly RF Unit PLL AssemblyRF Unit NJM2904V-TE1 IC RF Unit Logic Unit Logic Unit TDA7233D IC Logic Unit 200K ERJ3GE MP35 MP18 MP25 EP2 KEY Front PanelEP1 MP32 MP33 MP27 MP34 MP28 MP29 MP23 MP22 MP30 MP24 MP26 MP18 PLL Board Bottom View Schematic Diagrams and Component LayoutsPLL Board TOP View If Board Bottom View If Board TOP ViewRF Unit Transceiver Block DiagramMIC RF Board TOP ViewIf AMP RF Board SchematicHD1 Logic Board TOP ViewReceive Audio Processing Logic Board SchematicGND KEYR3 KEYR2 KEYR1 KEYR0 KEYS3 KEYS2 KEYS1 KEYS0 GND Display Board Bottom ViewDS3 DS4 DS5 Display Board SchematicKEY Board Back View KEY Board Front ViewS S R R R R KEY Board SchematicScan HC2 HC7 HC8 HC3 Schematic Diagrams and Component Layouts