03-02-2017, 01:50 PM
I think the Philco transformer should work fine. The 42 and the 6F6 are electrically identical, just the base is different.
Both radios use the same basic circuit with the tubes connected as triodes. The turns ratio difference is really not a problem, as with the step down ratio you have better low impedance drive to the grids of the 6F6 output tubes.
The problem with the little 5 Watt transformers they sell is that it can't handle the plate current of the 6F6 driver. They are meant to be driven by something like a 27 or a 6J5 and the core will saturate. Those transformers also can't pass the low bass freqs as well as the Philco driver, and they can't supply the drive necessary for class AB operation of the output tubes.
If you have a good driver transformer from a 116, I would definitely use it. Its just about the best replacement you will find.
Both radios use the same basic circuit with the tubes connected as triodes. The turns ratio difference is really not a problem, as with the step down ratio you have better low impedance drive to the grids of the 6F6 output tubes.
The problem with the little 5 Watt transformers they sell is that it can't handle the plate current of the 6F6 driver. They are meant to be driven by something like a 27 or a 6J5 and the core will saturate. Those transformers also can't pass the low bass freqs as well as the Philco driver, and they can't supply the drive necessary for class AB operation of the output tubes.
If you have a good driver transformer from a 116, I would definitely use it. Its just about the best replacement you will find.
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
