Winradio G315, Руководство пользователя

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WiNRADiO G315 VHF/UHF Receiver
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Appendix H – Frequency Calibration
The G315 receiver series features an excellent frequency accuracy and
stability for a receiver of its class. It is however possible to improve this
accuracy yet further, by individual calibration. One method of frequency
calibration was described in the
Calibration chapter. This method corrected
the tuned frequency by multiplying the displayed value by an adjustable factor.
Another method of frequency calibration is accomplished by inserting a
reference frequency parameter in the
WRG315.ini file which resides in the
Windows directory. The reference frequency parameter consists of two lines of
the following format:
[ClockCalibration]
receiver_serial_number=reference_frequency
The receiver serial number can be obtained for example from the About box in
the G315 application. The reference frequency is the actual frequency of the
internal reference oscillator in Hz. This is normally 16.384 MHz, i.e. 16384000
Hz.
Each receiver is factory calibrated, so a fundamental correction to the nominal
16.384 MHz reference frequency already exists and is stored in the receiver's
internal memory. This correction can be overridden by the new parameter in
the
WRG315.ini file. To determine the true offset from a perfect tuning, firstly
use 16384000 (i.e. the nominal reference frequency in Hz) as the
reference_frequency parameter. Say your receiver serial number is
02L27011:
[ClockCalibration]
02L27011=16384000
Save the WRG315.ini file with this value, then start the G315 application. The
frequency error will be now much worse because the new parameter overrides
the original factory calibration. Then tune the receiver to a known frequency
standard. A high-accuracy signal generator can be used, or one of the WWV
Time and Frequency Standard stations. Observe the peak with the spectrum
scope and listen to the beat frequency in the CW mode with a minimum IF
bandwidth. Then note down the frequency difference. (For example, -152 Hz
at 10 MHz).