12-22-2022, 04:26 AM
Hi TN,
a wonderful layout on that power supply, beautiful looking.
IMHO, yes, using 1.25 from the 2.5V winding would work, assuming y\that you are installing the "hum balance" rheostats used in the original PS. An alternative, if you have them is to replace the '26s with '01As, get an old computer power supply and use the 5V DC to power all the tubes except the '27. There will be much less hum.
BYW, what is wrong with the original power supplies? These are usually reliable, although sometimes the filter caps (oil / paper style) short. You can test the transformer by simply removing the '80 rectifier and checking voltages. If the transformer is good, you can simply replace the caps and chokes. Do note that that even though they look similar, the Radiola 18 PS is different from the Radiola 17 or Radiola 60 PS.
Below are 2 schematics from N/A, one for the Radiola 18, (similar to the schematic from Radiola Guy). The other is for the Victor 7-11, a radio / phono combo that uses the Radiola 18.
http://www.nostalgiaair.org/PagesByModel...040317.pdf (CAUTION! Do NOT use the voltage chart in this diagram, it is fr the DC Model!)
http://www.nostalgiaair.org/PagesByModel...040265.pdf
These are the same schematic, just presented differently. (RCA did not own Victor at the time). These may be useful. Unfortunately, no specification is given for the rheostats or resistors in either schematic. However, the schematic for the Radiola 33 is similar to the Radiola 18 and does contain resistor values (except for the rheostats), and also a voltage diagram (use the values for "Tubes in tester" and have the tubes installed in the radio. the schematic for the Radiola 33 is below:
http://www.nostalgiaair.org/PagesByModel...040328.pdf
You can measure the rheostat values, but you have to disconnect the wires from the transformer and tube sockets.
Hope this all helps! Best Regards and God's Blessings during this Holiday Christmas and Chanukah season!!
a wonderful layout on that power supply, beautiful looking.
IMHO, yes, using 1.25 from the 2.5V winding would work, assuming y\that you are installing the "hum balance" rheostats used in the original PS. An alternative, if you have them is to replace the '26s with '01As, get an old computer power supply and use the 5V DC to power all the tubes except the '27. There will be much less hum.
BYW, what is wrong with the original power supplies? These are usually reliable, although sometimes the filter caps (oil / paper style) short. You can test the transformer by simply removing the '80 rectifier and checking voltages. If the transformer is good, you can simply replace the caps and chokes. Do note that that even though they look similar, the Radiola 18 PS is different from the Radiola 17 or Radiola 60 PS.
Below are 2 schematics from N/A, one for the Radiola 18, (similar to the schematic from Radiola Guy). The other is for the Victor 7-11, a radio / phono combo that uses the Radiola 18.
http://www.nostalgiaair.org/PagesByModel...040317.pdf (CAUTION! Do NOT use the voltage chart in this diagram, it is fr the DC Model!)
http://www.nostalgiaair.org/PagesByModel...040265.pdf
These are the same schematic, just presented differently. (RCA did not own Victor at the time). These may be useful. Unfortunately, no specification is given for the rheostats or resistors in either schematic. However, the schematic for the Radiola 33 is similar to the Radiola 18 and does contain resistor values (except for the rheostats), and also a voltage diagram (use the values for "Tubes in tester" and have the tubes installed in the radio. the schematic for the Radiola 33 is below:
http://www.nostalgiaair.org/PagesByModel...040328.pdf
You can measure the rheostat values, but you have to disconnect the wires from the transformer and tube sockets.
Hope this all helps! Best Regards and God's Blessings during this Holiday Christmas and Chanukah season!!
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
Best Regards,
MrFixr55
