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Radiola 18 Amplifier & PS
#33

There is so much to take in, all interesting, but also making clear there is much to learn. Thank you both for the sustained information flow.

I doubt there is much reason to unpot the transformer, I need to check the remaining leads, but if their connections and outputs are good, leaving it as it is is probably best. 

The absence of the other RF tubes makes sense to explain the high voltages at terminal strip connections 7 & 8. I had recently read vacuum tubes have high internal resistance and was slowly beginning to understand that the initial readings of ~260V rather than 145V & 165V probably resulted from that absence. Thank you for suggesting this.

Perhaps I can find appropriate resistor values for a voltage divider to drop the terminal strip 7 & 8 voltages from ~260 to 145V & 165V, or perhaps there is a suitable resistor load I can add to the B+ to drop it. I have accumulated quite a few ceramic resistors from audio crossover cricuits I tried but have removed, as well as various other 5+ Watt WW resistors. 

At this point I'd be pleased to hear music through the 2 units, then decide a way forward. Actually, I did hear faint but distinct music through them, which suggests there may be something right, but also wrong in the transfer of the audio signal from the CD player to the #26 tube to the 71-A to the output to the 2K-8 Ohm output transformer. And no shortage of opportunities to learn!

I can take some of this to the electronics lab. for explanations and assistance, which is probably a good idea!

Thanks again.


Messages In This Thread
Radiola 18 Amplifier & PS - by TN Allen - 12-11-2022, 12:09 PM
RE: Radiola 18 Amplifier & PS - by Arran - 12-15-2022, 01:14 AM
RE: Radiola 18 Amplifier & PS - by TN Allen - 12-15-2022, 10:24 AM
RE: Radiola 18 Amplifier & PS - by Radioroslyn - 12-15-2022, 12:20 PM
RE: Radiola 18 Amplifier & PS - by MrFixr55 - 12-19-2022, 06:45 PM
RE: Radiola 18 Amplifier & PS - by TN Allen - 12-21-2022, 10:12 AM
RE: Radiola 18 Amplifier & PS - by TN Allen - 12-21-2022, 10:38 AM
RE: Radiola 18 Amplifier & PS - by MrFixr55 - 12-22-2022, 05:26 AM
RE: Radiola 18 Amplifier & PS - by TN Allen - 10-12-2024, 11:07 AM
RE: Radiola 18 Amplifier & PS - by Chas - 10-12-2024, 02:18 PM
RE: Radiola 18 Amplifier & PS - by MrFixr55 - 10-12-2024, 03:05 PM
RE: Radiola 18 Amplifier & PS - by Chas - 10-12-2024, 08:57 PM
RE: Radiola 18 Amplifier & PS - by Arran - 10-13-2024, 03:15 PM
RE: Radiola 18 Amplifier & PS - by morzh - 10-13-2024, 08:48 PM
RE: Radiola 18 Amplifier & PS - by MrFixr55 - 10-13-2024, 09:07 PM
RE: Radiola 18 Amplifier & PS - by Radioroslyn - 10-13-2024, 10:45 PM
RE: Radiola 18 Amplifier & PS - by morzh - 10-13-2024, 11:03 PM
RE: Radiola 18 Amplifier & PS - by TN Allen - 10-19-2024, 10:42 AM
RE: Radiola 18 Amplifier & PS - by TN Allen - 10-19-2024, 11:24 AM
RE: Radiola 18 Amplifier & PS - by MrFixr55 - 10-19-2024, 08:33 PM
RE: Radiola 18 Amplifier & PS - by Chas - 10-20-2024, 07:15 PM
RE: Radiola 18 Amplifier & PS - by TN Allen - 10-21-2024, 10:42 AM
RE: Radiola 18 Amplifier & PS - by Chas - 10-21-2024, 11:18 AM
RE: Radiola 18 Amplifier & PS - by MrFixr55 - 10-22-2024, 09:52 AM
RE: Radiola 18 Amplifier & PS - by TN Allen - 10-23-2024, 09:58 AM
RE: Radiola 18 Amplifier & PS - by Chas - 10-23-2024, 10:15 AM
RE: Radiola 18 Amplifier & PS - by TN Allen - 10-25-2024, 06:56 AM
RE: Radiola 18 Amplifier & PS - by TN Allen - 10-25-2024, 04:57 PM
RE: Radiola 18 Amplifier & PS - by TN Allen - 10-26-2024, 08:07 AM
RE: Radiola 18 Amplifier & PS - by TN Allen - 10-26-2024, 05:58 PM
RE: Radiola 18 Amplifier & PS - by MrFixr55 - 10-26-2024, 07:24 PM
RE: Radiola 18 Amplifier & PS - by Chas - 10-26-2024, 08:07 PM
RE: Radiola 18 Amplifier & PS - by TN Allen - 10-27-2024, 05:48 PM



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