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Below are all of the forum threads, including all
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Post subject: IF transformers from tube to transistor radios
Posted: Wed Jan 17, 2007 8:23 am
Joined: Fri May 19, 2006 5:01 am
In all tube radios that I've seen, the IF transformers have tuned primary and secondary windings. In transistor radios (where they used IF cans instead of ceramic filters anyway), only the primary is tuned. Why is this?
I can see the obvious advantage, in that you no longer need to "tune" the mutual coupling between the windings, but is this the only reason behind the change? If so, why did they insist on having a tuned secondary in tube radios?