The PHILCO Phorum

Hi all, David 16’s query in the Wanted Ads about an IF transformer is what prompted me to ask here. In a AA5 there is a transformer between the mixer and IF amp or what we call an input IF transformer. Then there is one between the IF amp and 2nd detector. My understanding is that these 2 transformers are not interchangeable because of the difference in impedance or loads the secondaries see between the 2 circuits or am I wrong? I ask because most radios I’ve seen have a different part number between the 2 except I have a cheap no name radio that had the same part number on both transformers. Can anyone shed some light here. Thanks

Ron

Yes that is correct. The 2ndys are different. Input trans is matching the grid of the I.F. amp (high z). The 2ndy of the output matches the diode load (low z). If you have an interstage transformer that can pass as an input transformer. This goes for all transformers not just Ktran.