09-08-2021, 02:27 PM
The purpose of the line caps is often misunderstood. Their main function is to provide an RF ground path for the antenna circuit. If you look at the schematic, you see the antenna coil is connected to chassis ground, in turn, the chassis is connected to the line through the line caps providing this ground path.. Try this experiment, remove the screw that fastens the line cap block to the chassis, lift the block so it no longer has a ground connection. turn the radio on. You won't notice much if any reduction in electrical noise/interference. What you find is a great reduction of sensitivity though. A few years ago, I restored a Philco 20. The Philco 20 originally had no line caps but, required a ground connection to the chassis for good performance. I decided to add line caps. After the caps were added, the radio worked equally well with or without the ground
Steve
Steve
M R Radios C M Tubes