11-12-2017, 12:43 PM
Jcassity;
Thanks for responding. You put a lot of work into your 46-1226 radio. I am glad you managed to get it working well again.
I have been reading your posts on your Code 125, and one thing that can be done to solve the AC + DC energy on R102 is to add an extra electrolytic capacitor right at the 5Y3 cathode. That filters the pulsating one-polarity AC pulses into DC with some ripple. That pretty much removes the AC energy from the equation at the beginning. Then the following stages can deal with just final filtering and bypassing. I believe you determined that the power transformer in your set had been changed. When power transformers are changed it is easy to wind up with additional problems if the replacement is not made to the original specifications of the manufacturer. I think that is one of the issues that caused you such grief in dealing with R102. My initial checks of the Philco OEM transformer in this set show it to be OK, so I likely will not have as much of a problem to deal with as you did on your set.
I will check the AC voltage to the plates of the 5Y3 and report back on what I measure there. If the original transformer design was not higher than required, there should not be that much of an issue to deal with as to the wattage rating of R102. After all, the radio I am working on had its R102 for many years before it finally failed.
On this radio, if the voltages measured at the screen grids and plates of the audio output tubes is correct it says that the power supply of the set is delivering about 92mA to the entire set through its B+ distribution. A 7-10 Watt R102 should be able to handle that without too much issue. Even a lesser wattage resistor might well be OK.
Joe
Thanks for responding. You put a lot of work into your 46-1226 radio. I am glad you managed to get it working well again.
I have been reading your posts on your Code 125, and one thing that can be done to solve the AC + DC energy on R102 is to add an extra electrolytic capacitor right at the 5Y3 cathode. That filters the pulsating one-polarity AC pulses into DC with some ripple. That pretty much removes the AC energy from the equation at the beginning. Then the following stages can deal with just final filtering and bypassing. I believe you determined that the power transformer in your set had been changed. When power transformers are changed it is easy to wind up with additional problems if the replacement is not made to the original specifications of the manufacturer. I think that is one of the issues that caused you such grief in dealing with R102. My initial checks of the Philco OEM transformer in this set show it to be OK, so I likely will not have as much of a problem to deal with as you did on your set.
I will check the AC voltage to the plates of the 5Y3 and report back on what I measure there. If the original transformer design was not higher than required, there should not be that much of an issue to deal with as to the wattage rating of R102. After all, the radio I am working on had its R102 for many years before it finally failed.
On this radio, if the voltages measured at the screen grids and plates of the audio output tubes is correct it says that the power supply of the set is delivering about 92mA to the entire set through its B+ distribution. A 7-10 Watt R102 should be able to handle that without too much issue. Even a lesser wattage resistor might well be OK.
Joe
