03-13-2013, 10:15 AM
I just noticed that Philco and Riders use different component designations. So if you you have the Riders schematic, you'll have different reference numbers. My copy of Riders is almost illegible, so I can't give you corresponding references. Follow the path from the detector diode through the IF can secondary to find the 22K resistor and then to the 2.2 Meg after the split at the volume control.
I saw a reference in Chapter 12 of Marcus and Levy "Elements of Radio Servicing" that looks like it describes your symptoms. If reception is poor because of problems between the antenna and the RF tube, the lowered signal might cause your AFC to act like you're tuned to a weak station all the time, so it'll over boost all stations. Check the 30 mmf mica cap between the ends of the antenna loop. (C1 on my Riders schematic, C400 on the Philco.) There's also a .0015 mF cap (C2 on Riders, C403 on Philco) that you might check out. Also any connection in the loop antenna and its connection to the chassis or to the external antenna connections could create this kind of problem.
I saw a reference in Chapter 12 of Marcus and Levy "Elements of Radio Servicing" that looks like it describes your symptoms. If reception is poor because of problems between the antenna and the RF tube, the lowered signal might cause your AFC to act like you're tuned to a weak station all the time, so it'll over boost all stations. Check the 30 mmf mica cap between the ends of the antenna loop. (C1 on my Riders schematic, C400 on the Philco.) There's also a .0015 mF cap (C2 on Riders, C403 on Philco) that you might check out. Also any connection in the loop antenna and its connection to the chassis or to the external antenna connections could create this kind of problem.
John Honeycutt
