06-05-2020, 01:57 PM
Hi, Terry.
This happens while trying the AM alignment. I'm using a 600Hz sine wave to modulate a 455kHz carrier at 30%. The input goes in the tuning capacitor stator, and the scope is connected to the speaker leads.
I was expecting to get the same 600Hz sine wave at the speaker terminals. The sine wave is there, but at 1200Hz. The pitch sounds much higher.
Same result with a dummy load replacing the speaker.
Trying the same method on other radios produces the expected results, so it shouldn't be related to the signal generator or scope.
Thanks
JZ
This happens while trying the AM alignment. I'm using a 600Hz sine wave to modulate a 455kHz carrier at 30%. The input goes in the tuning capacitor stator, and the scope is connected to the speaker leads.
I was expecting to get the same 600Hz sine wave at the speaker terminals. The sine wave is there, but at 1200Hz. The pitch sounds much higher.
Same result with a dummy load replacing the speaker.
Trying the same method on other radios produces the expected results, so it shouldn't be related to the signal generator or scope.
Thanks
JZ
