Jim gave you an excellent analysis of what happened to your CFL. That fixture might have contributed to the failure, and I'd be suspicious of it unless that CFL is several years old or it was a very cheap "bargain" brand.
Here's why. The ballast circuit in the base produces some heat. It's not a huge amount, but enough to make it very warm. It needs cooling, especially in fixtures that have a reflector above the lamp to direct the light downward, such as onto your desk. If it doesn't have enough holes at the top part of the fixture to let lots of air pass around the lamp and the ballast in its base, then out through the ventilation holes, you'll shorten the life of the CFL. I believe the life span of the CFL is related to price too. My "evidence" is purely anecdotal, but strong enough that I avoid the cheap "bargain" CFLs. I've been using GE CFLs for several years after some lower priced CFLs failed after only a few months of service. I use all sizes from 40-watt (equivalent) 'warm light' CFLs for reading lights to big ones equivalent to 100 watt 'daylight' (5800K) lights on the work bench. I haven't changed a single CFL in years. The "100 watt" CFLs are in swing-arm fixtures with cone-shaped reflectors that have a ring of holes around the switch at the back of the socket that lets air pass by easily. Although the CFL itself gets too hot to hold onto after extended use, the metal reflectors get just slightly warm to the touch and I've experienced no failures yet. I have also observed the RFI generated by both "bargain" and the GE bulbs. There's a huge difference, at least with the bargain CFLs I've used. The RFI from a bargain CFL anywhere in the shack would be plainly audible across at least part of the HF spectrum, but I have to hook a wire to the rig antenna jack and put it quite close to the GE CFLs to hear any noise at all. I'm not making claims that the GE CFLs are superior to all others. It just happens that after I had RFI issues with some cheap no-name units that also failed quite early, I did a little research and went looking for a better brand. The GEs happen to be the brand I picked up and I've had no need to replace one since. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
