Ron wrote: > Many antenna systems do not require this protection. They are shunt fed > which provides a direct-current short across the feed line at all times. > > Chokes may work fine, but all chokes have some parasitic capacitance across > the windings which means they have a series resonances somewhere across the > RF spectrum.
Even in the "dark ages", most US WWII military aircraft HF receivers like the famous BC-348-series were modified to install a 1 Mohm resistor from antenna terminal to ground to dissipate antenna static. Static voltage build-up on wire antennas external to the aircraft in motion could otherwise build up quite high. The other approach was using a small neon bulb (NE-2) in place of the resistor. Compared to choke or neon bulb, the resistor seems to be the most elegant solution in terms of simplicity with no detectable adverse consequences. Chuck wrote: > Which begs the question...why isn't a 100K across the antenna jack in the > original design? Good question...with no known good answer. :-) 73, Mike / KK5F ______________________________________________________________ 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
