[600MRG] Low RF Noise LED Light Bulbs

[Michael Mussler]

I recently installed ceiling lights in my new ham shack. I discovered that fluorescent tube fixtures no longer use ballast transformers; using a switching circuit instead with attendant RFI issues. I found equivalent LED lights (in terms of Lumens) at Home Depot made by Lithonia. Before purchasing them, I corresponded with the Lithonia application engineer, a real person located right here in the USA, about my RFI concerns. He provided information on EMI performance for their products in addition to the detailed lighting specifications already listed on the web. I tested one of the fixtures, locating it right next to my radio gear and antenna entry to the shack. RFI was minimal- barely detectable on the lower ham bands during quiet ambient background conditions. I could find no RFI with the fixture located more than about three meters from the ladder line running into my ham shack. 

Satisfied with the information I received from Lithonia and my shack test results, I decided to install seven of the fixtures in the ceiling of my second floor ham shack. They cover about a 480 square foot area. Each one is equivalent in size and lighting to a two-tube 4 ft. fluorescent fixture, but use significantly less energy. Unlike fluorescent tubes they are not affected by cold ambient temperatures. The LED fixtures cost more, but energy savings will eventually pay for the cost difference. The LED lifespan is supposed to be longer than the fluorescent tubes and there are no haz-mat disposal issues. 

As noted by John Langridge, everyone has a different situation in terms of antenna designs, transmission lines, power wiring and other loads in the home or ham shack. Your results may vary from what I experienced. Considering the worse case RFI scenario, the power conversion circuit that came with the Lithonia lamps could be replaced with a linear DC supply to power the LED strips in the fixtures. There is enough space inside the fixture for such a circuit. 

Mike Mussler, AI8Z
ex WD2XSH/12