10-31-2013, 07:02 AM
Terry,
Most of the issues have been resolved I think. First, I have been placing the - lead of the VM on Test point B. I did not mention this before not thinking that it mattered but those power checkes were done with the unit attached to a dim bulb tester. It occured to me that the power will be low with that arrangement, and it was. My power check is as follows:
Test Point A 180 (high)
Test Point C 255 (high)
Test Point D 129 (low)
Voltages on the 14AF7 are
Pin 3 120
Pin 6 126
Pin 7 7.9
I was also conducting the oscillator test incorrectly. It measures -4.2, so I am happy with that.
The audio transformer is ok. I tested it by touching a wire to it and listened for a pop. I heard one.
But I have no audio. The only thing I hear is scratching in the speaker that sounds like a nearby thunderstorm heard on the AM dial. There is a hum that gets louder as I turn the volume up.
Any thoughts? Could the unit be out of alignment that it receives no stations?
Terry
Most of the issues have been resolved I think. First, I have been placing the - lead of the VM on Test point B. I did not mention this before not thinking that it mattered but those power checkes were done with the unit attached to a dim bulb tester. It occured to me that the power will be low with that arrangement, and it was. My power check is as follows:
Test Point A 180 (high)
Test Point C 255 (high)
Test Point D 129 (low)
Voltages on the 14AF7 are
Pin 3 120
Pin 6 126
Pin 7 7.9
I was also conducting the oscillator test incorrectly. It measures -4.2, so I am happy with that.
The audio transformer is ok. I tested it by touching a wire to it and listened for a pop. I heard one.
But I have no audio. The only thing I hear is scratching in the speaker that sounds like a nearby thunderstorm heard on the AM dial. There is a hum that gets louder as I turn the volume up.
Any thoughts? Could the unit be out of alignment that it receives no stations?
Terry
