Resistors used in Model 20 - Printable Version

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+--- Thread: Resistors used in Model 20 (/showthread.php?tid=24595)

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RE: Resistors used in Model 20 - MrFixr55 - 10-01-2023

Did the John Grady Interstage Transformer Mod described in the Library by Ron R and replaced the old replacement caps in my own Philco 20.  Big difference!  My friend's interstage is a total mess and is already bridged with an 0.033uF 200V cap without the 27K Ohm dropping resistor, so this is going to be redone properly.

In the process of replacing caps and resistors on my friend's 20.  All the blocks have been stuffed.  Unfortunately, all of those pretty resistors have to go, as they are all totally out of range.  Morzh was dead on correct as usual. Ron and all, thx for the resistor rating. I intend to use 1 watters or half wat paralleled as necessary. I wonder if they can be drilled on a hidden side to break the connections then solder replacement resistors hidden behind the originals.  the 2 500K jobs read about 5 meg, but I am afraid of them being noisy, and the "customer" (my friend) is not looking to have a pristine restoration of the chassis underside.

After that, I will break the connections inside the filter cap can and install new ones under the chassis.  My friend will be tasked with chassis rust and dirt cleanup, can polishing and painting.

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RE: Resistors used in Model 20 - Arran - 10-01-2023

Mike;
Back in 1929-30 the 71A was nearly obsolete, whereas the #45 was the latest, and greatest, thing, Philco never used anything without looking at a balance sheet, they literally designed sets around whatever they could get cheapest at the time or in quantity. As for what the audiophools are willing to pay they really are fools with the 171As, you can't even get one watt out of a single ended one, and the plate voltage maxes out at 150 vdc. The only good thing about them is you can use them as the power output on a 1920s battery set since they are a 5 volt tube that only draw .25 amps.
Regards
Arran

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