08-13-2017, 09:54 PM
I thought about a little upgrade for the model 20 and found a spot to attach a female audio jack with future plans to drill a hole into the rear of the chassis to mount the female AUX input. I soldered ground to ground and the left & right audio inputs together on the low side of capacitor #19.
Volume for the AUX input isn't controlled by the radio itself, but instead from the input device (my cell phone for example). What's nice is that when the AUX is unplugged the radio audio then returns to whatever it was tuned to. If the radio does cut in while the AUX is plugged in, then the radio volume can just be turned down.
I've been running AUX audio through the radio for several hours with no issue. Here's the circuit diagram with the left & right connection point (marked with a red arrow), some pics and a video. I was pretty excited that it worked, so there's a bit of giggling on the video...
[Video: https://youtu.be/57Ugih6a4DY]
[Image: https://www.dropbox.com/s/4r345m39ffuymn...t.gif?dl=1]
[Image: https://www.dropbox.com/s/j3ygbmuo6a9ez4...n.jpg?dl=1]
Volume for the AUX input isn't controlled by the radio itself, but instead from the input device (my cell phone for example). What's nice is that when the AUX is unplugged the radio audio then returns to whatever it was tuned to. If the radio does cut in while the AUX is plugged in, then the radio volume can just be turned down.
I've been running AUX audio through the radio for several hours with no issue. Here's the circuit diagram with the left & right connection point (marked with a red arrow), some pics and a video. I was pretty excited that it worked, so there's a bit of giggling on the video...
[Video: https://youtu.be/57Ugih6a4DY]
[Image: https://www.dropbox.com/s/4r345m39ffuymn...t.gif?dl=1]
[Image: https://www.dropbox.com/s/j3ygbmuo6a9ez4...n.jpg?dl=1]
- Eric
Philco 20A
Zenith T825
