Color television of a panda is automatic channel of the part when search stage is ceaseless stage, do not remember. Tear open below among them, with YZ - 4 model corrective appearance surveys the week in color television its frequency is 44.24MHZ, capacitance of the buy inside the week in this is nigrescent, with small in after week shift is changed to 43MHZ generation, this machine returns to normal - - this is stuck to turn!
Oneself are in a normal TCL - 1419A (decipher is: TB1238) fold in color television below 236560 in Zhou Ce quantity also is 43M (inside buy capacitance is sealed dried meat, capacitance capacity looks from the exterior lesser) . The intermediate frequency of high frequency head should be 38M left and right sides, week resonance frequency is 43M however in, do not know why?

Answer: What need affirmation above all is, the signal of this generation on syntonic loop when circuit works is 38 megacycle.

The week in this is the component in regarding oscillation of circuit of the VCO inside chip as loop in circuit, this and the chip that resemble TA7680 and so on differ completely, this kind of circuit is circuit of frequency lock photograph actually, in-house circuit comprises the week in this and core to be pressed for together accuse an oscillator. In the VCO circuit that locks up photograph circuit, chip presses the volts d.c. that accuses capacitance to will be outputted by phase comparator in-housely to adjust, this capacitance and exterior in the capacitance on week is shunt-wound, generally speaking, of this kind of means in the capacitance of week paralell connection is lesser, otherwise chip is pressed in-housely accuse capacitance adjusting range will very narrow, cannot realize frequency and phasic synchronous lock finally to decide. The basis locks up the characteristic of photograph annulus circuit or principle, the frequency that the free oscillation frequency of the oscillator ought to obtain than the requirement is a bit more tallish ability is locked up to decide by synchronism. Accordingly, your test is correct, in fact, to similar circuit, medium when week of outer ministry test or calibration, what syntonic frequency can compare a requirement is tall, specific for how many, decide in the ability on the foundation of practice even.