Hi everyone!

I have been trying to construct an AM receiver. Now the transmitter is no problem, infact it works very nicely. The only problem im having is that when I measure the ground wire with an oscilloscope I find that the AM signal is present on this wire. Im sad to say I dont have a schematic which im personally using but this is as close to the design as it gets

Has anyone encountered any similar problems?

 

What are measuring with respect to?
Is the common of the supply actually connected to earth ground?
(Shades of a Cats Whisker radio)
Max.

 

Puzzling question. Assuming the ground wire of the oscilloscope is connected to the ground wire of the circuit, then you measure the ground wire with the oscilloscope probe, you should have zero in both AC and DC. Something is missing here. Please elaborate.

 

Well the GND on the oscilloscope is connected to the same ground in the AM circuit. After some other tests I think my transmitter is interfering with the power supply and scope.

tomorrow, transmitter far away as well as the radio circuit using a battery as opposed to the PSU

Im sorry if I cant give any more info, i feel bad just for asking

 

If you are radiating the AM signal with an antenna then the ground current from the antenna radiation current is going through the ground return until if finds earth ground. The voltage that you see would likely be due to that current.