If your radio will accept an external antenna, try connecting a dipole antenna to it and play with the orientation. Might help or eliminate the problem for FM. Do a google search on dipole antenna. Easy to make from TV antenna wire.
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New LED lights cause buzzing in radio
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11-07-2018, 12:30 PM
Because LED's run on DC those fixtures have a power supply in them that would be a switching power supply and probably switching around 60KHz. One though is the radiated EMI and harmonics of the switching frequency is being picked up by your antenna or something in your radio. Being it's older probably analog radio so everything is probably getting passed through.
I don't think the noise is being conducted because you said separate circuits but they do share a common ground probably. Try unplugging the antenna and see if that helps.  (11-07-2018, 12:30 PM)Brian in sunny FL Wrote: I don't think the noise is being conducted because you said separate circuits but they do share a common ground probably. Try unplugging the antenna and see if that helps. I was going to suggest plugging into another receptacle that's on the other hot leg in the panel, though the neutral and ground are common. Any row that's an odd number of rows from the row the existing receptacle is on, even if he has to test with an extension cord, since they alternate between L1 and L2. Assuming the usual two column by however many rows (up to 20, typically). Quick to do, and costs nothing.
Tom
“This place smells like that odd combination of flop sweat, hopelessness, aaaand feet"
11-07-2018, 06:05 PM
(11-07-2018, 12:30 PM)Brian in sunny FL Wrote: Because LED's run on DC those fixtures have a power supply in them that would be a switching power supply and probably switching around 60KHz. One though is the radiated EMI and harmonics of the switching frequency is being picked up by your antenna or something in your radio. Being it's older probably analog radio so everything is probably getting passed through. I am assuming the buzzing is 60hz because they probably switch at much higher frequencies to save money on magnetics. The power supplies in the leds probably have a poor power factor and are putting harmonics out on the line. Wouldn't matter if they were on the same circuit as long as they are on the same leg. I am curious if those old "bulb saver" caps would do anything about this. Or a input filter on the radio.
11-07-2018, 08:04 PM
(11-07-2018, 06:05 PM)EricU Wrote: I am assuming the buzzing is 60hz because they probably switch at much higher frequencies to save money on magnetics. The power supplies in the leds probably have a poor power factor and are putting harmonics out on the line. Wouldn't matter if they were on the same circuit as long as they are on the same leg. I am curious if those old "bulb saver" caps would do anything about this. Or a input filter on the radio. Eric - A pretty common type problem that comes up on the radio boards fairly often. If you have soldering skills, pretty easy to reduce - may not eliminate. Most common is to have a 0.1µf capacitor from each leg of the power grounded to the radio chassis. These may already be there - could have failed. If not there or if you wish to replace and understand how to do so safely - I'd be happy to send you a pair of appropriate caps. A better solution is a small filter unit like found on most all desktop computer power supplies. Basically a filter unit to eliminate all frequencies except 60 cps. They take a grounded 3 prong plug to the wall socket and have two connectors to go to original power connections inside the radio. These can be pretty expensive - but PM me if you're comfortable soldering one in. Tom also see: http://www.antiqueradios.com/forums/sear...mit=Search
11-08-2018, 12:08 PM
My audio recording equipment has all the grounds, but I could still hear a slight hum while recording. I took a piece of braid wire, bundled bare wire on each end and stuck each end in the ground sockets from the multi plug to the wall plug and the hum goes away. Never tried to find the reason why - too many possibilities- microphones, guitars, amps, piano, drums and many cords, so I leave it- and Life is good.
11-09-2018, 01:09 AM
Hopefully tomorrow I will get a chance to check things our further. I'll try a newer digital radio and try grounding it and shielding the power cord.
If none of those tricks help I'll start looking at filters. Thanks for the ideas and leads. I do want some good music to listen to when I'm not making too much noise! 
"Truth is a highway leading to freedom" --Kris Kristofferson
Wild Turkey We may see the writing on the wall, but all we do is criticize the handwriting. (joined 10/1999)
11-10-2018, 11:23 AM
(11-09-2018, 01:09 AM)Wild Turkey Wrote: Hopefully tomorrow I will get a chance to check things our further. I'll try a newer digital radio and try grounding it and shielding the power cord. Type of filter I was talking about - https://www.goldmine-elec-products.com/p...ber=G21593
11-10-2018, 03:15 PM
I expect it's over-the-air, not power line, interference. Two things I would try:
1. Test with a battery-powered radio. If you hear the same noise, it's not coming from the power line. 2. You may just have one noisy bulb. Take them all out and put them back one at a time. If the bulb is not noisy, leave it in. When you hear the noise, take that bulb out and try another one until you find which one(s) are noisy. If they're all noisy then you're back to where you started. Kevin |
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