Keep CFLs away from the Radio

[jon]

A friend recently watched 16:9 on Global, with their CFL (Compact Fluorescent Light) expose (not sure how to do E Acute). And thought it would be good to mention a fact touched upon briefly in the show.

When you buy CFLs, be sure to try medium wave DX'ing with them turned on during the period when you can still return them to wherever you bought them. 16:9 would have you believe that all CFLs are created equal, and are horrendously noisy, from an RF perspective. Historically, tube fluorescents of the '60s were documented as peaking at 600 KHz for their strongest RF interference.

My own tests found that RF levels of CFLs vary, so be sure to do your own tests. The Philips ones that I bought last summer emit so little as to be undetectable with a decent ghetto blaster tuned to a quiet frequency about 5 feet from the bulb. But don't just blindly buy Philips, as I found a seemingly identical bulb, same model and same packaging, that generated a completely different colour of white light (I didn't test the RF).

Bottom line: CFL is a new technology, and is very likely to have lots of unexpected problems, either Quality Control type issues or Design issues. Be sure to test each bulb you buy.

The main issue for me, though not related to DX, is worth mentioning: some CFLs blink 120 times a second, while others do not. I used a turntable and a strobe disc to test that. The strobe discs were designed to synchronize the speed of the turntable under fluorescent tubes of the '60s & '70s. Blinking that fast is not a problem for most people, especially now that CRTs are on the way out of existence. CRTs, including TVs and computer monitors, used to blink at different rates than fluorescent tubes, causing headaches and other health issues. But some people, including me, do have trouble with stand-alone fluorescents that blink 120 times a second. For some reason, high ceilings seem to make it worse, perhaps because you get light from more bulbs over a larger area.