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Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
AFT and remote control AFT and remote control CircuitsCircuits
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
Importance of AFCImportance of AFC Receivers that have provisions for remote Receivers that have provisions for remote
tinning have no provision for remote fine tinning have no provision for remote fine tuningtuning
Color receivers that have provisions for Color receivers that have provisions for remote tuning to obtain the best color remote tuning to obtain the best color reproductionreproduction
Many customers found it difficult to adjust Many customers found it difficult to adjust the manual fine tuning control propertythe manual fine tuning control property
A very slight drift in the frequency of the A very slight drift in the frequency of the tuner oscillator causes a loss of color tuner oscillator causes a loss of color picture qualitypicture quality
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
Troubleshooting AFT circuitsTroubleshooting AFT circuits
Weak or no AFT performanceWeak or no AFT performance No picture no sound raster okNo picture no sound raster ok Large tuning errorLarge tuning error Moment to moment picture Moment to moment picture
variationsvariations
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
Ultrasound remote controlUltrasound remote control
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
Causes of AFT problemsCauses of AFT problems
A defective transistor or associated circuitsA defective transistor or associated circuits A defective transformer A defective transformer defective IC or associated circuits such defective IC or associated circuits such
as an open coilas an open coil Misalignment of the AFT tuned circuitsMisalignment of the AFT tuned circuits Incorrect power supply voltageIncorrect power supply voltage Defective varactorDefective varactor Incorect varactor voltageIncorect varactor voltage
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
AFT circuit that uses dc amplifier to AFT circuit that uses dc amplifier to drive the varactordrive the varactor
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
Large tuning error on channels that Large tuning error on channels that originates form the varactororiginates form the varactor
DC amplifier balance change caused DC amplifier balance change caused by the change in resistor anywhere by the change in resistor anywhere in the DC amplifierin the DC amplifier
Defective varactorDefective varactor
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
Remote control CapabilityRemote control Capability
Change channelChange channel Adjust volumeAdjust volume Adjust picture Adjust picture Adjust contrastAdjust contrast Adjust sharpnessAdjust sharpness Sound quality adjustmentSound quality adjustment Power switchPower switch
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
Remote controlsRemote controls
Ultrasonic TransmitterUltrasonic Transmitter– Acoustic transmitterAcoustic transmitter– Function by tune signals from receiver Function by tune signals from receiver
to transmitter to transmitter
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
Ultrasound Ultrasound remote remote controlcontrol
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
Kinds of remote control faultsKinds of remote control faults
Weak intensive response on all Weak intensive response on all functionfunction
Dead all functionDead all function Dead on some function but not allDead on some function but not all
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
Electronic memory remote controlElectronic memory remote control
Producing ultrasonic sound through Producing ultrasonic sound through electronic circuit controlled system.electronic circuit controlled system.
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
Three tone remote controlThree tone remote control
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
Infrared systemInfrared system
Using invisible infrared signalUsing invisible infrared signal Digitally modulated infrared signal Digitally modulated infrared signal
42 KHz sensed by infrared diodes.42 KHz sensed by infrared diodes.
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
Infrared remote controlInfrared remote control
Television 1 Jess Role @ Television 1 Jess Role @ UEAB2006UEAB2006
AFT discriminator circuitAFT discriminator circuit