Now I have narrowed all my radio problems down to my power adapter.
My power adapter is a "stringer" model BA-630.
It outputs 6V, 300mA and it states its input is 117VAC 60Hz 5W.
I cut the connector of my adapter off and replaced it with a battery snap connector so I can use it like a battery. The battery snap connector added maybe 1 inch to the total cord length. The total cord length that came with the adapter is about 1 meter.
In my circuit, I have tried my own PI filter.
I connected +ve to -ve through these capacitors that are connected in parallel: a 1mF, a 33nF, and a 4.7nF.
then I connected +ve to a 2-pin large inductor that I made out of a 5-pin audio transformer. The other pin connects to the rest of the circuit that normally connects to +ve. The other pin alco connects to a 1mF capacitor which also connects to ground. a 33nF capacitor is tied in parallel with the 1mF capacitor.
I just described my PI network. the 1mF capacitors are electrolytic and the rest of them are ceramic disk.
It seems thatthe power cord functions as an antenna. If I have it in one position, I have constant hum. If I move the power cord to a different location, I don't get it the same. Sometimes, I get smooth white noise. It all depends on where I move the cord.
How come my power cord is doing this, and how can I stop it from functioning as an antenna?
Please help ASAP. Thanks.
My power adapter is a "stringer" model BA-630.
It outputs 6V, 300mA and it states its input is 117VAC 60Hz 5W.
I cut the connector of my adapter off and replaced it with a battery snap connector so I can use it like a battery. The battery snap connector added maybe 1 inch to the total cord length. The total cord length that came with the adapter is about 1 meter.
In my circuit, I have tried my own PI filter.
I connected +ve to -ve through these capacitors that are connected in parallel: a 1mF, a 33nF, and a 4.7nF.
then I connected +ve to a 2-pin large inductor that I made out of a 5-pin audio transformer. The other pin connects to the rest of the circuit that normally connects to +ve. The other pin alco connects to a 1mF capacitor which also connects to ground. a 33nF capacitor is tied in parallel with the 1mF capacitor.
I just described my PI network. the 1mF capacitors are electrolytic and the rest of them are ceramic disk.
It seems thatthe power cord functions as an antenna. If I have it in one position, I have constant hum. If I move the power cord to a different location, I don't get it the same. Sometimes, I get smooth white noise. It all depends on where I move the cord.
How come my power cord is doing this, and how can I stop it from functioning as an antenna?
Please help ASAP. Thanks.