Took some screenshots from my 8924c spectrum analyzer illustrating the interference produced by various brands of LED bulbs.
Of the four I checked, the "Osram" brand bulb produced the least, about 1-2dB of background noise. Barely noticeable on the screenshots, so I didn't take one. The "GreenWatt" bulb was next, with about 2.8dB of noise. The "Panasonic" bulb produced an interesting ripple effect on the 20Mhz span screenshot, peaking at 6dB of noise. The TCP bulb was the worst, at 10-12dB; however worth noting that it is a "smart" connected bulb, controllable from smart phone via a wireless hub device.
Also looked at a "Great Value" brand compact fluorescent bulb and couldn't find anything worth noting.
Test setup: telescoping BNC antenna about 6" from light bulb
