I have homemade adjustable spark gaps on my open wire line. It’s important to realize that voltages from normal operation on open wire lines can be quite high. My installation is atypical since I run a very high SWR on some bands, but the TLW program calculates as much as 7kv at the entrance to my shack on 40 meters! I saw some serious arcs before I got everything sized properly. I got a couple of 10 meg 10kv resistors from Mouser to use as static drains.
Victor 4X6GP > On 31 Oct 2018, at 1:18, Fred Jensen <[email protected]> wrote: > > Open wire feedlines used to have "spark balls" for lightning protection on > high power transmitter installations. Admittedly, the transmitters used tubes. > > 73, > > Fred ["Skip"] K6DGW > Sparks NV DM09dn > Washoe County > >> On 10/30/2018 2:32 PM, rv6amark via Elecraft wrote: >> Re: "Spark plugs fire at 12,000 to 25,000 Volts. Some require as much as >> 45,000 V." >> >> That is at the pressure inside the combustion chamber. At atmospheric >> pressure, they fire at much lower voltages; however, Walter's point is still >> valid. Turn on voltage is far more reliable with gas discharge tubes. >> Sparkplugs were probably more helpful with tube gear than with today's >> solid state gear. >> >> Mark >> KE6BB >> >> >> null >> ______________________________________________________________ >> 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 >> Message delivered to [email protected] >> >> -- >> This message has been scanned by E.F.A. Project and is believed to be clean. >> >> > > ______________________________________________________________ > 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 > Message delivered to [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 Message delivered to [email protected]
