| 摘要 |
Disclosed is a digital tuning indicator for an automatic direction finder (ADF) equipment used in aircraft comprising a counter to measure the ADF local oscillator frequency, off-set logic modify the measured count to reflect the intermediate frequency representing the difference between the local oscillator frequency and the desired incoming frequency, and a digital display to provide an exact indication of the frequency of the incoming station to which the system is tuned. The off-set logic operates by resetting the counter when it reaches a count equal to the intermediate frequency thereby subtracting this value from the total count accumulated during each operating cycle. Control of the foregoing is provided by a timing generator or programmer which establishes the counting and data display intervals.
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