11-28-2016, 11:42 AM
Sorry, I have old man eyes. How about this one? A 166J25:
http://www.digikey.com/product-detail/en...-ND/270154
There is a 166M25 version with a 3 amp rating which would be more what I need, right? In this radio, the chassis is fairly small and squarish. Inside the cabinet, there is tons of open space.
It would be more elegant (I guess that is the right word) to swap all of the tubes for their 6 volt varieties and change the output to a 6V6, but I know for a fact that my grip on theory isn't up to it. My tube manual says that the 6 volt versions of all of the 12 volt tubes are electronically identical, so (except for changing the heater voltage) I would not need to make any changes there, I suppose. It is changing the 25L6GT to a 6V6GT that worries me. The value of the resistor between the plate of the 12SQ7 and the 25L6GT is 100 ohms, so that needs to be more like 300 if I change it to a 6V6, right? I do actually have an output transformer and speaker matched to a 6V6 around here that came out of a Crosley 66Cs but the cone is a bit rough...I wonder if I could canabalize the OT and match it to the Stewart Warner FC and speaker? Probably not. But the changes to R13, 10, and C 27, C 28, C38, and C 59 A and B? Plus anything else I'm missing from ignorance? It would be a great education for me, and force me to finally get better at calculating resistances and impedances.
Like I said, I kind of love the cabinet, and the phono input is a plus, so I'd like to get the set working one day.
http://www.digikey.com/product-detail/en...-ND/270154
There is a 166M25 version with a 3 amp rating which would be more what I need, right? In this radio, the chassis is fairly small and squarish. Inside the cabinet, there is tons of open space.
It would be more elegant (I guess that is the right word) to swap all of the tubes for their 6 volt varieties and change the output to a 6V6, but I know for a fact that my grip on theory isn't up to it. My tube manual says that the 6 volt versions of all of the 12 volt tubes are electronically identical, so (except for changing the heater voltage) I would not need to make any changes there, I suppose. It is changing the 25L6GT to a 6V6GT that worries me. The value of the resistor between the plate of the 12SQ7 and the 25L6GT is 100 ohms, so that needs to be more like 300 if I change it to a 6V6, right? I do actually have an output transformer and speaker matched to a 6V6 around here that came out of a Crosley 66Cs but the cone is a bit rough...I wonder if I could canabalize the OT and match it to the Stewart Warner FC and speaker? Probably not. But the changes to R13, 10, and C 27, C 28, C38, and C 59 A and B? Plus anything else I'm missing from ignorance? It would be a great education for me, and force me to finally get better at calculating resistances and impedances.
Like I said, I kind of love the cabinet, and the phono input is a plus, so I'd like to get the set working one day.
Charlie in San Antonio
