06-01-2013, 08:43 AM
I have read several threads regarding Philco 16B voltages. My set is code 121 with the 80 rectifier. The voltage table in Riders says the printed table is for code 122 with the 5Z3 rectifier. Does anyone know if the code 121 voltages are significantly different than the code 122 voltages? And does the data pack sold at Philco Repair Bench contain the correct voltage table for the code 121?
My radio has been restored and works on all bands. All caps have been restuffed, resistors checked and replaced if not within 20%, and tubes tested and replaced if needed. But my voltages are not even close to the voltages in the 122 table in Riders!
Line voltage is 116 volts. Plate voltages for the 77 1st detector is 186, 78 1st IF 187, 78 2nd IF 193 - spec is 220-230. The screen voltages for all the above is 79.7 (spec is 80). 42 driver plate is 187.8 - spec is 220. 42 output plate is 270 - spec is 340.
So it looks like my B+ is low. But I was concerned that I was not using the correct voltage chart. Again, the radio works, and nothing is overheating. Resistance to ground for B+ is right on specification (6.85K with the speaker field connected, and 53K with it disconnected.
My radio has been restored and works on all bands. All caps have been restuffed, resistors checked and replaced if not within 20%, and tubes tested and replaced if needed. But my voltages are not even close to the voltages in the 122 table in Riders!
Line voltage is 116 volts. Plate voltages for the 77 1st detector is 186, 78 1st IF 187, 78 2nd IF 193 - spec is 220-230. The screen voltages for all the above is 79.7 (spec is 80). 42 driver plate is 187.8 - spec is 220. 42 output plate is 270 - spec is 340.
So it looks like my B+ is low. But I was concerned that I was not using the correct voltage chart. Again, the radio works, and nothing is overheating. Resistance to ground for B+ is right on specification (6.85K with the speaker field connected, and 53K with it disconnected.
