EFJohnson 764X, 761X service manual Adjustment Procedure, Test Setup, Suggested Test Equipment

Page 56

ADJUSTMENT PROCEDURE

SECTION 6 ADJUSTMENT PROCEDURE

 

50 Ohm, 50W

 

Load

 

Wattmeter

 

Frequency

 

Monitor

 

13.6 Volt, 17A

Programming Cable

Power Supply

Part No. 585-7500-031

 

 

4.0 Ohm Speaker Load

Test Cable (Fabricated)

 

Figure 6-1

Test Setup

6.1 GENERAL

6.1.1 SUGGESTED TEST EQUIPMENT

The equipment that should be used to adjust this transceiver is listed in the following table.

Equipment

Grade and Range

 

 

 

DC power supply

Output voltage

13.6 VDC

 

Current capacity

15A

 

 

 

RF power meter

Measuring range

1-50 W

 

Freq range

146-512 MHz

 

Impedance

50 ohms

 

SWR

Less than 1.2:1

 

 

 

Frequency counter

Freq range

0.1-500 MHz

 

Freq accuracy

±1 ppm or better

 

Sensitivity

100 mV or better

 

 

 

Equipment

Grade and Range

 

 

 

FM deviation

Freq range

DC-520 MHz

meter

Measuring range

0 to ±10 kHz

 

 

 

Audio generator

Freq range

67-3000 Hz

 

Output level

1-500 mV

 

 

 

Attenuator

Power atten.

50 or 60 dB

 

Capacity

50W

 

 

 

Standard Signal

Freq range

146-520 MHz

Generator (SSG)

Output level

0.1 µV-32 mV

 

 

(–127 to –17 dBm)

 

 

 

DC voltmeter

Input impedance

50kΩ/V DC or

 

 

better

 

 

 

Oscilloscope

Freq range

DC-20 MHz

 

Measuring range

0.01-20V

 

 

 

AC millivoltmeter

Measuring range

10 mV - 10V

 

 

 

External Speaker

Input Impedance

4 Ω

 

Power Capacity

5 watts min.

 

 

 

 

November 1998

6-1

Part No. 001-7600-001

Image 56
Contents 761x VHF 764x UHF Conventional Mobile Conventional FM TWO-WAY Radio Table of Contents Table of Contents CONT’D Schematic Diagrams and Component Layouts General Information 75xx Accessories AccessoryToll-Free 800 Factory ReturnsReplacement Parts Internet HomeThis page intentionally left blank VHF and 7640 UHF Mobile Specifications GeneralGeneral Information Installation and Disassembly Transceiver InstallationInstalling Mounting Bracket Installing Microphone HangerPower Cable Installation Cable InstallationPower Cable Fuses Changing 20-Ampere Power Cable FusesUsing AN External Speaker Accessory Cable InstallationRemove shield E Transceiver DisassemblyRemoving PC Board 2-TONE/5-TONE Module Installation Installation ProcedureSetting 5-Tone Deviation 2 2-TONE ProgrammingInstallation and Disassembly Features OperationBasic Operation Controls and DisplayTransceiver Back Panel Direct Selection The F1-F4 Receiving and Placing Calls TIME-OUT Timer Programmable FunctionsOption Key Programmable Functions Function Key Label Description Section NoMonitor Mode Select Output Power SelectCall Guard Tone Select Channel SelectChannel Scan Priority Channel Sampling Programming Setup Section ProgrammingProgramming Cables Programming SoftwareStarting the Program Special Keys and FunctionsMenu Flow File MenuScreen Menu Program MenuPrint Menu Model MenuParameter Description Bank Select Setup MenuMemory Channel Screen Description LMR Models Timer Ch AtrFrequency Rx/TxAuto Reset LockoutScan ToneKey and Display Assign Screen Description Key DescriptionKey Description Label RF Power Dtmf Autodial Screen DescriptionSelection Bank/FreeParameter Description Continuous Tone Screen DescriptionScan Function Screen Description Stop Timer 2-Tone Code Channel Screen DescriptionResume Auto CHEXO Timer Timer Auto TxAuto Tx StunCommon Screen Description Expert Screen Description Unique PMR European Screens Unique PMR ScreensCloning Programming ONE Transceiver with Another Memory Channel Screen PMR Models This page intentionally left blank VHF 7610 Circuit Description VHF Receiver CircuitAudio Amplifier Circuit Receiver Mute CircuitPower Amplifier Module VHF Transmitter CircuitMicrophone Amplifier Circuit Modulation CircuitPLL Circuit APC CircuitVHF PLL Circuit Pin Port Description VHF IC PIN DescriptionsLine Description VHF I/O Expander IC5 Main Unit PinVHF Port Expander IC11 Main Unit Pin Port Description NameUHF 7640 Circuit Description UHF Receiver CircuitSecond if System IC1 UHF UHF Transmitter Circuit PLL Circuit UHF UHF PLL CircuitUHF Power Supply UHF CPU IC1 Port AllocationUHF I/O Expander IC12 Main Unit UHF Port Expander IC13 Main UnitAdjustment Procedure Test SetupSuggested Test Equipment Equipment Grade and RangeTest Channels Test CableUHF Test Frequencies COMPUTER-AIDED TuningVHF Test Frequencies VHF Adjustments VHF AdjustmentsPreliminary Setup PLL Adjustment VHF ModelsFM Deviation Adjust VHF Adjustments CONT’DOutput Power Adjust Dtcs Waveform Adjust Receiver Adjustments VHF ModelsBandpass Filter Adjust Squelch AdjustBeep Tone Level Adjustment Beep Tone LevelTransmitter Adjustments UHF Models UHF AdjustmentsPLL Adjustment UHF Models UHF Adjustments CONT’D UHF Adjustment PointsUHF Adjustments CONT’D Receiver Adjustments UHF Models Parts List Æçìíýõ9+ôý0$,1ý81,7Íäç HUDPLFý&ìçíåý-%ýì+ýìíë.ð7ð$ Íëëðêäíçðíçí Íäæ Ìää HUDPLFý&ìçíåý-%ýì&ýìíé.7ð1 Íëëðêäíçðçìé Ëíí Ëäí HUDPLFý&ìçíåý-%ýìýìíê.ð7ð$ Íëëðêäíçðíçê Ëäì RLOý0/ìçíå$ýì5í.ð7 Íëëðêäíçðçèç 03ì Ýìäëëý9&2ýFDVH 5íéé 5HVý5-ê*-ýìííý9ýõìíýRKPô Íëëðêäíçðìêå 5íéè 5ìèé 5HVý5-ê*-ýìíéý9ýõìííýNýRKPô Æçéíýõ8+ôý0$,1ý81,7 Íêì HUDPLFý&ìçíåý-%ýì+ýìíë.ð7ð$ Íëëðêäíçðíçí Íêë Íäé HUDPLFý+0çí6-ý&+ýíêíýèíí9ý Õéäíðèìëý0+ô Ìèì 5HIý1Rï Êëç Íëëðêäíçðäèë 4éì 7UDQVLVWRUý7&êçê.ý7ìéæ 5íæé 5ìçå 5HVý5-ê*-ýìíéý9ýõìííýNýRKPô 5217ý81,7 Õ9+ý$1ý8+ý02/6ô =HQHUý0$åíèìð0ýõ7ô Æçìíýõ9+ôý&+$66,6ý3$576 VHF 7610 Exploded View Front UnitUHF 7640 Exploded View Schematic Diagrams and Component Layouts VHF 7610 Block DiagramMain Unit Front UnitVHF 7610 Transistor Basing Diagrams Foldout → VHF 7610 Main Board TOP View VHF 7610 Main Board Schematic VHF Main UnitUHF 7640 Block Diagram UHF 7640 Main Board Bottom View UHF 7640 Main Board TOP View J4 T o O p tion al Un itUHF 7640 Main Board Schematic VHF/UHF Front Unit Board TOP View VHF/UHF Front Unit Board Bottom ViewVHF/UHF Front Unit Schematic UHF 7640 Transistor Basing Diagrams