Nice demos and a reminder of just how dangerous QRO RF can be - to people and to property.
In my commercial work I learned to be as careful around RF as I am around any high voltage - especially after accidentally drawing a small arc from an RF source. Messing with 50 or 100 watt Ham rigs from which we often "drew an arc" with a pencil from a high-impedance point made me careless. My QRO burn only made a small black patch on my skin, but it felt exactly like a nail had been shoved through my flesh - and it felt like the nail was still there for days! RF burns are deep burns that injure a lot of tissue and nerves. If I had been doing that YouTube demo, I'd certainly have worn the welding mask and more than that T-shirt in case some hot metal bounced around. Until now, a solid state amp could do limited damage because it would fail in milliseconds. The demos show these solid state amps are as robust as vacuum tube amps, and so they are just as dangerous. And we all should remember that one doesn't have to draw an arc or get a surface burn to do deep tissue damage from an RF field. That's why there are firm guidelines for RF field exposure. RF can set fires too. G3BDQ tells the story of the Ham whose end-fed wire ran through a hole drilled in his wooden window frame. Every time he held the key down a curl of smoke would come out of the hole. Ron AC7AC -----Original Message----- > >> >> On 7/24/2011 8:07 AM, Olli Tuppurainen wrote: >>> Here is one alternative for HF + 6m >>> >>> http://www.nikkemedia.fi/juma-pa1000/ >>> >>> >>> Olli >>> OH6CT >>> >>>> On Sun, Jul 24, 2011 at 1:28 PM, Gary K9GS<[email protected]> wrote: >>>> >>>>> There has been an ongoing discussion on the AMPS reflector regarding >>>>> the Freescale LDMOS devices currently on the market. A pair of >>>>> these in an HF amp with a 48V SMPS would be an excellent > start.....(hint, >>>>> hint...KPA-1500). I wish I was retired and had some time on my > hands >>> :) >>>>> Check this out: >>>>> >>>>> http://www.w6pql.com/1_kw_2m_ldmos_amplifier.htm >>>>> >>>>> Also see: >>>>> >>>>> Some YouTube videos... >>>>> http://www.youtube.com/watch?v=02v58cnb41o&feature=relmfu >>>>> http://www.youtube.com/watch?v=-EACUpIhpac >>>>> >>>>> F1JRD also has an article in Dubus >>>>> http://www.qsl.net/f1jrd/MRFE6VP61K25H.html >>>>> http://www.w6pql.com/1_kw_2m_ldmos_amplifier.htm >>>>> Gary K9GS ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
