09-19-2015, 02:49 PM
I'm working on a 41-255. Both primary legs of the push-pull output transformer (P/N: 32-8120) are open with respect to the center tap. I searched the Phorum to find advice on a replacement and found this thread: http://philcoradio.com/phorum/showthread...098&page=2
On the basis of this information I ordered a Hammond 125B. When it came I measured the primary resistance and noticed that the two legs of the primary had different resistance with respect to the center tap. 124 ohms / 172 ohms. The original did, too, (170 / 190), but with the Hammond the difference is much greater.
The schematic marks which 41 output tube the 190 ohm resistance leg of the 32-8120 goes to (the tubes are not wired identically.) I know that winding inductance, not resistance, is the critical factor, but otherwise the workings of transformers are a mystery to me. My question for those who do understand transformers is: does it matter which primary wire of the Hammond I attach to which 41 tube?
On the basis of this information I ordered a Hammond 125B. When it came I measured the primary resistance and noticed that the two legs of the primary had different resistance with respect to the center tap. 124 ohms / 172 ohms. The original did, too, (170 / 190), but with the Hammond the difference is much greater.
The schematic marks which 41 output tube the 190 ohm resistance leg of the 32-8120 goes to (the tubes are not wired identically.) I know that winding inductance, not resistance, is the critical factor, but otherwise the workings of transformers are a mystery to me. My question for those who do understand transformers is: does it matter which primary wire of the Hammond I attach to which 41 tube?
John Honeycutt
