Two Field Days ago I brought along a little clip-on lamp. It was small, bright and very convenient. Its 12v bulb was powered by a tiny switching supply.
It was only turned on for about a minute. Now I call it the Hissing Lamp from Hell. I don't know if it also generates the usual unstable noise vortices that roll around the bands, but it does produce a loud wideband hiss that sounds like nothing as much as the noise generator that I use to adjust my K2's filters. In fact, I could use it for that purpose. Cheap switching supplies: really bad technology whose time has come! On 7/19/2010 8:15 AM, Jim Brown wrote: > On Sat, 17 Jul 2010 12:47:44 -0400, John Ragle wrote: > >> But...my overall >> opinion is that switching power supplies have taken a bad rap. > > There are switching power supplies and there are switching power > supplies. Not all are created equal. If you go to an electrical > supply store to buy a transformer to run 12V lighting, they will > sell you a switching power supply that is a holy terror. They call > it an electronic transformer. Ask them for a real transformer and > you get a blank stare. > > Most wall warts that provide DC power for battery charging, or to > run consumer electronics of all sorts are switching power supplies. > Many of them are quite noisy. > > 73, Jim Brown K9YC -- Vic, K2VCO Fresno CA http://www.qsl.net/k2vco/ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
