Post by Druid Hills Radio on Apr 18, 2017 18:03:47 GMT
DIRECT vs INDIRECT METHOD: The operating power of LPFM stations may be determined by either the
direct or indirect method. The direct method of power determination for a LPFM station uses the indications of a
calibrated transmission line meter located at the RF output terminals of the transmitter. This meter must be
calibrated whenever there is any indication that the calibration is inaccurate or whenever any component of the
metering circuit is repaired or replaced.
The indirect method is determined by applying the appropriate factor to the input power to the last radiofrequency
power amplifier stage of the transmitter, using the following formula:
Transmitter output power = Ep x Ip x F
Where: Ep = DC input voltage of final radio stage.
Ip = Total DC input current of final radio stage.
F = Efficiency factor of the transmitter.
direct or indirect method. The direct method of power determination for a LPFM station uses the indications of a
calibrated transmission line meter located at the RF output terminals of the transmitter. This meter must be
calibrated whenever there is any indication that the calibration is inaccurate or whenever any component of the
metering circuit is repaired or replaced.
The indirect method is determined by applying the appropriate factor to the input power to the last radiofrequency
power amplifier stage of the transmitter, using the following formula:
Transmitter output power = Ep x Ip x F
Where: Ep = DC input voltage of final radio stage.
Ip = Total DC input current of final radio stage.
F = Efficiency factor of the transmitter.