Ron, Excellent advice. Many years ago I built a 832A high-level tripler for 432 to drive with my 2m transmitter. The output was not that high probably only a couple watts at 432. I was adjusting the plate tuning and got zapped with RF which punched a tiny hole thru one of my fingers. At first I thought it was HV but the metal I was handling was grounded. It hurt for three weeks. Felt like a hot number-22 wire had punched thru.
73, Ed ------------------------------ Message: 23 Date: Sun, 24 Jul 2011 14:53:16 -0700 From: "Ron D'Eau Claire" <[email protected]> Subject: Re: [Elecraft] Could the be the basis for the KPA-1500? To: <[email protected]> Message-ID: <005201cc4a4c$18c8bb40$4a5a31c0$@biz> Content-Type: text/plain; charset="us-ascii" 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 73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 50-1.1kw?, 144-1.4kw, 432-100w, 1296-60w, 3400-? DUBUS Magazine USA Rep [email protected] ====================================== ______________________________________________________________ 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
