03-09-2012, 07:48 PM
Hi Eric,
The -7.2 voltage is good. That means your oscillator is working. The voltage chart is incorrect with no minus sign preceding the 7.5V. If the oscillator was not working it would explain stations weak and at different spots on the dial. You can also use a AM transistor radio near the radio to hear the oscillator beat.
Using a 22uF or 33uF cap for C-45 will help with hum. A slight hum is usually OK.
The crackling noise is good sign on the 6sk7 tube. You are creating white noise which is theoretically all frequencies which is able to pass through all the stages.
Check that the antenna coils show continuity too.
Richard
The -7.2 voltage is good. That means your oscillator is working. The voltage chart is incorrect with no minus sign preceding the 7.5V. If the oscillator was not working it would explain stations weak and at different spots on the dial. You can also use a AM transistor radio near the radio to hear the oscillator beat.
Using a 22uF or 33uF cap for C-45 will help with hum. A slight hum is usually OK.
The crackling noise is good sign on the 6sk7 tube. You are creating white noise which is theoretically all frequencies which is able to pass through all the stages.
Check that the antenna coils show continuity too.
Richard
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