Maintenance Log, WJLD Transmitter


b8f41a - Maintenance log - WJLD transmitter - Jan 29, 1986.jpg


Maintenance Log, WJLD Transmitter


Box 8 Folder 41: "All right, moving right along. Folder 41 is a maintenance log from the Johnston Broadcasting Company and this from January of 1986. In the FCC regs, it tells us that transmitter output power = ep x ip x efficiency factor "f" where ep equals the DC input voltage of the final radio frequency amplifier stage; and ip equals the DC input current of the final radio frequency amplifier stage. FCC regs also says calculations from these measurements can be tolerated at between 100% and 110% of authorized power output.

Applying these conclusions to the ep and ip figures on the maintenance log, we multiply 2850 by .440. The product is 1254 watts. If these calculation are correct, the efficiency factor would be .797...(f = 1000/1254)... (which seems high)..which would correct erp down to 1000 watts.

From the WJLD files."



“Maintenance Log, WJLD Transmitter,” The Birmingham Black Radio Museum, accessed July 23, 2021,

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