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Telephone ic for remote control

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New Member
Hai friends

I am using ic um91214 for remote control and for transmitting .I am using fm transmitter.This ic uses 3.58MHz crystal and it is telephone ic which generate different freq for different switch . I wanted to know that the generated freq gets added up with crystal freq or not


Well-Known Member
Most Helpful Member
The datasheet for the old touch-tones dialer IC shows its audio touch-tones frequencies.
Google also shows touch-tones frequencies.
The very high crystal frequency is not produced in its touch-tones output.

Have you modified your FM radio so that it can receive touch-tones? Its de-emphasis equalization might need to be removed.


Then you need to add some to add pre-emphasis to the transmitter circuit, please post it.
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