[Leo.G (Leo)]

Diamond Dot MN-C6B




I've been asked to overhaul/resurrect/restore and old (1963-64) Air Chief car radio for a friend of a friend whose recently purchased an immaculate EH Holden.
My first issue is identifying the impedance of the original speaker so as not to blow the output transistor. From what I can find it's 15 Ohm impedance which I can do with an 8 Ohm unit with a resistor in series (yet to do the maths but probably around 14 Ohm will cover it (or 2 x 8Ohm speakers in series) for my testing purposes, that part is easy.
Then figure out why several wires have been cut internally. A circuit diagram would be lovely, probably as rare as a lotto win.
I used to trace/draw them out by hand, my eyes aren't so good now (it's a simple old circuit board compared to modern stuff with minuscule surface mount components).

Some of these systems had speakers with a mounted transformer, would anyone have any idea where I'd find this information?
Radiomuseum has the radio but no specific information.
I know there's members here who restore cars and likely have knowledge and I'd appreciate any information anyone can offer.


Thanks!