Replacing 1st and 2nd IF transformers - Printable Version

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Replacing 1st and 2nd IF transformers - Tubeglow20 - 10-10-2020

Want to replace the small IF transformers on a GE model 401 with the larger capacitive tuned transformers.  This chassis has the holes for the larger transformers mounting studs although it looks like either transformer could be used. GE used both the small inductiveley tuned transformers as well as the larger capacitively tuned transformers on the models 400, 401, and 411 although the schematic shows the larger transformers.  Maybe they used the smaller ones in later sets? Later models like the 412 and 416 used the smaller transformers,  but the chassis and components were about the same. On the schematic with the large transformers,  it shows a DC resistance on the windings of 24 ohms. I have obtained a set of transformers off of ebay that all measure 13.8 ohms. Was wondering if it would cause a problem if I use these transformers with a different DC resistance value? Any thoughts or ideas? Thanks!!!

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RE: Replacing 1st and 2nd IF transformers - Radioroslyn - 10-10-2020

Size and resistance doesn't matter so much what does is the resonant frequency. If it's 455kc your good. But if they are the small Ktran style transformer they are prone to develop smd. The input and output transformers are somewhat different impedance wise is it's good to determine which is which.

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