Low End Audio Noise
Posted: Sun Aug 06, 2017 12:43 am
I am concerned about a condition I have with unwanted energy on the low end of my audio passband. There is low frequency energy present even when I disconnect my accessory plug (DB25) in the back. This disconnects my microphone and PTT connection from the rig. I have tried changing my power supply to no avail (still have the problem). I have tested the rig at full power and at 5 watts and the problem still exists.
CONDITION : There is energy at 30hz , 60hz and 120hz. There are "little carriers" 10 to 20db above the rest of the passband quiescent power. These blips of energy exist when everything is disconnected except the power supply and the computer. I have a picture of the condition and have submitted it. I can reduce these energy carriers when I drop the EQ bands in the 30hz to 120hz region. This kills the low end of my transmitted audio. What could this be??? The condition exists even if I use the front microphone connection, I transmit into a dummy load, no matter what!!! HELP!!! John K2YN
P.S. I am using HPSDR 3.4.2
CONDITION : There is energy at 30hz , 60hz and 120hz. There are "little carriers" 10 to 20db above the rest of the passband quiescent power. These blips of energy exist when everything is disconnected except the power supply and the computer. I have a picture of the condition and have submitted it. I can reduce these energy carriers when I drop the EQ bands in the 30hz to 120hz region. This kills the low end of my transmitted audio. What could this be??? The condition exists even if I use the front microphone connection, I transmit into a dummy load, no matter what!!! HELP!!! John K2YN
P.S. I am using HPSDR 3.4.2