10-01-2022, 02:03 PM
Hi Keefer,
A major amount of hum and interference is created by computers, fluorescent lights, CFLs, LEDs, etc. It is absolutely amazing. I cannot play an AM Radio in my office, even with an external antenna unless I shut off the LEDs, computer, Displays, etc. There is noise even from the power company using the distribution wires as a carrier current path for the "Smart Meters, etc. Even taking a portable radio outside, when I get close to the house, the noise starts.
To diagnose, turn the volume down. If the hum is gone, your filters should be OK. However, take all of the advice from Fenbach and others about replacing all paper and electrolytic caps.
The controls that you are touching that change the sound: Are they the volume and tone controls, or are they the "Padder" caps for the tuning caps or IF transformer adjustments? If the latter, touching with a metallic screwdriver may change the level / quality of the sound depending if the screw is above ground potential. If merely touching the volume and tone controls, whose shafts are usually at chassis ground level, then try touching the case of the radio itself. If the change also occurs when touching the radio case, it is likely not at ground potential. Ground it, and touching the radio should not change performance unless you are between the radio and the signal.
Do ensure that you have an antenna of some sort connected to the radio. A vertical wire about 42" should work if you are not in the basement. This approximates the whip antenna used with the car, that your radio is trimmed to. However, a "long wire" antenna should work fine.
A major amount of hum and interference is created by computers, fluorescent lights, CFLs, LEDs, etc. It is absolutely amazing. I cannot play an AM Radio in my office, even with an external antenna unless I shut off the LEDs, computer, Displays, etc. There is noise even from the power company using the distribution wires as a carrier current path for the "Smart Meters, etc. Even taking a portable radio outside, when I get close to the house, the noise starts.
To diagnose, turn the volume down. If the hum is gone, your filters should be OK. However, take all of the advice from Fenbach and others about replacing all paper and electrolytic caps.
The controls that you are touching that change the sound: Are they the volume and tone controls, or are they the "Padder" caps for the tuning caps or IF transformer adjustments? If the latter, touching with a metallic screwdriver may change the level / quality of the sound depending if the screw is above ground potential. If merely touching the volume and tone controls, whose shafts are usually at chassis ground level, then try touching the case of the radio itself. If the change also occurs when touching the radio case, it is likely not at ground potential. Ground it, and touching the radio should not change performance unless you are between the radio and the signal.
Do ensure that you have an antenna of some sort connected to the radio. A vertical wire about 42" should work if you are not in the basement. This approximates the whip antenna used with the car, that your radio is trimmed to. However, a "long wire" antenna should work fine.
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
"Let us begin to do good"- St. Francis
Best Regards,
MrFixr55
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