05-02-2021, 02:02 PM
Have a question to throw out there about the audio transformers in this radio. I have a copy from an A-K data sheet, page 8-1. It does verify that both audio transformers should have the identical primary and secondary resistance. Primary 1700 ohms, secondary 3250 ohms. The data sheet is for a Model-20 #7570.
They next state the same audio transformer is used in the model-20 # 4640, (what I have). They state for radio model 20 # 4640 transformer part# 7661 is used in both the 1st and 2nd stages.
They also state that the transformer for the radio 20 model# 4640 is part# 7661.
The transformer for radio 20 model #7570 is part # 4779.
They go on to say even though each model has a different transformer part numbers, they are the same audio transformer.
So... all that as a prelude to my question.
Can two different transformers with the same primary and secondary resistance 1700/3250 ohms have a different turns ratio if one of them was wound with a larger diameter wire?
Feel free to respond in a manner that lets me know I'm being dense. Just trying to get a handle on having two transformers that match the factory data sheet resistance wise. But may be incorrect ratio wise. It would be nice to have some clarification before I go to the trouble of installing them.
Like any newby, I might have my jock strap on backwards and don't even know it yet.
They next state the same audio transformer is used in the model-20 # 4640, (what I have). They state for radio model 20 # 4640 transformer part# 7661 is used in both the 1st and 2nd stages.
They also state that the transformer for the radio 20 model# 4640 is part# 7661.
The transformer for radio 20 model #7570 is part # 4779.
They go on to say even though each model has a different transformer part numbers, they are the same audio transformer.
So... all that as a prelude to my question.
Can two different transformers with the same primary and secondary resistance 1700/3250 ohms have a different turns ratio if one of them was wound with a larger diameter wire?
Feel free to respond in a manner that lets me know I'm being dense. Just trying to get a handle on having two transformers that match the factory data sheet resistance wise. But may be incorrect ratio wise. It would be nice to have some clarification before I go to the trouble of installing them.
Like any newby, I might have my jock strap on backwards and don't even know it yet.