Quote:
Originally Posted by DavGoodlin
Congratulations, you have discovered a solution we can use.
What was the secondary voltage on the power transformer you found and did you use the primary winding for anything?
|
The transformer came out of a gutted Heathkit AG-9a audio generator. I think the HV output was probably around 300v, and the fil. voltage at 6.3.
I used the HV B+ winding of the transformer for the audio primary (red, yellow-red, red) and the fil. voltage for the speaker output (greed, green).
117v wires (black, black) are unused but they do come out to around 15 ohms I believe, so theoretically they could have been used for another speaker supporting a higher impedance.
Measuring with a multimeter I got around 320ohms from Common to each red wire. and 3ohms on the filament wires.
Quote:
Originally Posted by old_coot88
Yessir, a power tranny will work. Response rolls off dramatically above about 5khz, but that's still plenty adequate broadcast quality.
|
I haven't swept the transformer yet on a scope but it sounds like the highs are there just fine. It may roll off some but with the design of the radio I doubt the speaker itself would reproduce much above 5kHz.
Quote:
Originally Posted by drdave3
What did you do to get that grime off the chassis?
|
Just a good dusting, then scrubbed with a cloth and some warm water. Owners do not care how shiny the metal looks when finished so just went for a basic clean.
Oddly the transformer sounds really good and distortion free.
Trying this transformer was a shot in the dark but it works wonderfully!