Thanks, Ignacio, not good news for sure.? I was thinking of making and installing an AC line filter in line with the cord since the snap over ferrite wasn't doing anything, but not sure now if it would do any good.? I may be able to access the lamp internally as there are screws at both ends.? Can you suggest a schematic for a filter circuit I may be able to try for the switching supply to LED output?
Thanks!
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On 6/23/21 5:43 AM, EB4APL wrote:
A problem with these "fluorescent tube" LEDs is that the tube itself acts as an antenna and radiates. Unless the switching power supply is very well made, which is not very common,? its pulses are very steep and not controlled and so they produce interference that is radiated and conducted. The conducted one can be stopped with the ferrites at the input but the radiated one is quite difficult to eliminate, you need to filter the power supply output to the LEDS. The solution could be to change the power supply (not always possible) or changing the whole fixture.
Regards,
Ignacio EB4APL
El 23/06/2021 a las 1:23, JonI via groups.io escribió:
Tony's revamping of the HF to LF SDR, and its arrival today, caused me to further track down interference since it was worse on LF.? I've managed to find and eliminate almost all such sources now with one exception:? I run an LED "fluorescent" light in the kitchen.? It's a small unit with obvious switching power supply within. Unfortunately, it causes interference around 4 Mhz.? A trick I tried with my cordless phone base, also causing interference, and that trick was wrapping the power supply wires through a couple of ferrite cores, is not working with the LED fluorescent.? It continues to cause a buzz in HF.? It's a safety hazard to one of the occupants living here not to have the light plugged in 24/7, so I would appreciate any suggestions you might have.
Thanks!
Jon
