Transmitter Performance Tests, Power Output | EFJohnson 7780

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

Image 83

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

Contents

7780 Page Page Table of Contents Table of Contents CONT’D List of Figures List of Tables Scope of Manual Equipment Description General Information Transceiver Identification AccessoriesFactory Customer Service Part Number Breakdown Factory Returns AccessoriesAccessory Toll-Free 800 Definitions Replacement PartsInternet Home Intrinsically Safe Information Classification of Hazardous Areas and Atmospheres Temperature Code T3CPossible Ignition Sources Intrinsically Safe and Nonincendive Ratings Area Classification Accessing PC BoardsMaterial Classification Typical Hazard Group Class Removing Logic Unit Removing RF Unit General Specifications Controls and Display FeaturesTransceiver Operation Low-Battery Indicator Amber TX Indicator Red Indicates when the transmitter is keyed Display DisplayFront Panel Keys Full Keypad Model Backlight Turning Power on and Setting VolumeOption Switches General Operation See Option Switch FunctionsFunction Conv Scanning Tone ENABLE/DISABLE Conventional 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 Select Priority Channel Sampling Standard Conventional Calls DTMF/ANI Signaling Enhanced Private Conversation Calls SMARTNET/SMARTZONE FeaturesViewing Unit ID Standard Group Calls Transceiver 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 Programming Help Files Connecting RPI to Computer and TransceiverStarting and Exiting Programming File Types Creating and Displaying Systems Screen Pop-Up Buttons and File Size IndicatorProgramming Procedure File Size Indication Menu Bar Menu Commands Window Menu Radio Type MenuDownload Menu Upload Menu Systems Menu Zones DefaultsRADIO-WIDE Parameter Screens Band Assign Function Buttons Radio Wide Scan ListRadio-Wide Scan List Screen Modify List Screen Hot Dtmf RADIO-WIDE Conventional ScreenRADIO-WIDE SMARTNET/SMARTZONE Screen Full Spectrum CC Scan Conventional System General Screen Adjustable ParametersRADIO-WIDE Portable Options Screen Programming Conventional Systems and Channels Scan List Button TimersConventional System Modify Scan List Screen Keypad Editing Priority Channel Selection Scan TimersSetting UP Conventional Channels Selected Channel Conventional Channel Screen Parameters Tx Time-Out Transmit PowerSignaling Channel Type Splinter Channels Restricted AccessTime-Out Timer ISW Delay Time Private Call SMARTNET/SMARTZONE System Other ID’S ScreenSMARTNET/SMARTZONE System Phone Interconnect Screen Phone Interconnect Failsoft Channel SMARTNET/SMARTZONE System Emergency Settings ScreenEmergency Alarm SMARTNET/SMARTZONE System Talk Groups Screen Message Aliasing Screen SMARTNET/SMARTZONE System Lists ScreensTrunking Phone List Screen Control Channels Screen Announcement Groups Screen Trunking Call List Screen SMARTNET/SMARTZONE Channel Screen Parameters Setting UP SMARTNET/SMART- Zone ChannelsStatus Aliasing Screen Other Screen Parameters SMARTNET/SmartZone Channel Screen Recommended Tone Call Guard Codes Freq Call Guard CTCSS/DCS Codes and Tones MHz Channels MHz Channels MHz Channels MHz Channels MHz Channels MHz Channels Synthesizer Description Power Switching and RegulationPower Switching Circuit Description Charge 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 Description Receive Audio Processing Control Logic and Display Pin Port Name Input or Description Active High Output Microprocessor IC306 Pin Descriptions Hvfulswlrq Receive Data FILTER/DETECTOR IC102A/B, IC107A/B Audio Amplifier IC104-IC106Receive and Transmit Data Processing Transmit Audio Processing Transmit Data Filter IC206B/ IC206A Smartnet Data Processing LOW-PASS Filter IC205A/B Function Fahrenheit Celsius Battery Pack and Charger InformationBattery Pack Power Setting Operating Time Battery Pack and Charger Information Test Setup Alignment Procedure and Performance Tests Mm/3/32 Mm/1/8 Phone Jack Tune Software Hqhudo Main Pctune Screen Preliminary Setup Modulation Balance Transmit Frequency and PowerTransmit Power Adjustment Screen High Power Level = 3.0 watts Low Power Level = 1.0 watt Data Deviation Squelch AdjustRssi Adjust Audio Deviation Receiver Performance Tests Performance Tests Transmit Modulation Power OutputTransmitter Performance Tests Transmit Frequency This page intentionally left blank Ref No Description Parts ListDisplay Assembly Chassis Parts Display Assembly KEY Assembly If Assembly If AssemblyKEY Assembly RF Unit PLL Assembly RF Unit NJM2904V-TE1 IC RF Unit Logic Unit Logic Unit TDA7233D IC Logic Unit 200K ERJ3GE MP35 MP18 MP25 EP2 KEY Front Panel EP1 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 View RF Unit Transceiver Block Diagram MIC RF Board TOP View If AMP RF Board Schematic HD1 Logic Board TOP View Receive Audio Processing Logic Board Schematic GND KEYR3 KEYR2 KEYR1 KEYR0 KEYS3 KEYS2 KEYS1 KEYS0 GND Display Board Bottom View DS3 DS4 DS5 Display Board Schematic KEY Board Back View KEY Board Front View S S R R R R KEY Board Schematic Scan HC2 HC7 HC8 HC3 Schematic Diagrams and Component Layouts