02-19-2014, 08:41 PM
Please refer to the revised image below.
[Image: https://philcoradio.com/images/phorum/Fi...ltages.jpg]
The above revised partial schematic contains actual voltage readings I took tonight in red.
I did not measure any appreciable voltage across the right speaker terminals, with speaker connected or disconnected.
I tried removing C20 from the circuit and using a 100 uF cap in its place. Volume was as low as before.
I carefully unsoldered two joints so that I could properly measure resistors R36 and R38 - they are nearly perfect. I also unsoldered one leg of diodes CR6 and CR8; they test good.
So I am now puzzled as to why the voltages, which are 25.1V at the base of Q7 and 25.3V at the emitter of Q7 and the collector of Q9 are 19.3V at the base of Q8, 19.6V at the emitter of Q8, and 19.7V at the collector of Q10.
Oh, and I also removed the right channel wire which leads to the volume control and bridged it to the left channel - the volume is still much lower in the right channel.
I think this one has me stumped for now.
[Image: https://philcoradio.com/images/phorum/Fi...ltages.jpg]
The above revised partial schematic contains actual voltage readings I took tonight in red.
I did not measure any appreciable voltage across the right speaker terminals, with speaker connected or disconnected.
I tried removing C20 from the circuit and using a 100 uF cap in its place. Volume was as low as before.
I carefully unsoldered two joints so that I could properly measure resistors R36 and R38 - they are nearly perfect. I also unsoldered one leg of diodes CR6 and CR8; they test good.
So I am now puzzled as to why the voltages, which are 25.1V at the base of Q7 and 25.3V at the emitter of Q7 and the collector of Q9 are 19.3V at the base of Q8, 19.6V at the emitter of Q8, and 19.7V at the collector of Q10.
Oh, and I also removed the right channel wire which leads to the volume control and bridged it to the left channel - the volume is still much lower in the right channel.
I think this one has me stumped for now.
--
Ron Ramirez
Ferdinand IN