I am just coming back to radio after an absence of a few months. My latest development is the plug-in IF transformer. This is for a proposed 4 valve battery superhet using TP25, VP23, HL23DD and PEN25, Mazda octal valves. I require plug in IFs so that I can experiment with making my own IF transformers once the set is working. Also planning on plug in coils.
The IFs are mounted on old octal valve bases. I have removed the internal 65pf capacitors, and these will be replaced by trimmers on the chassis. I need to clean the pins up a bit, but this was just the prototype. The Ifs came from an old suitcase battery set.