Thanks, guys. I've read K9YC's paper before, but needed to be reminded of it!
73, KS4L On Nov 5, 2012, at 1:46 PM, Jim Miller <[email protected]> wrote: > Read all but if lazy just go to cookbook near end: > http://audiosystemsgroup.com/RFI-Ham.pdf > > For some useful more detail analysis: > http://fermi.la.asu.edu/w9cf/articles/balun.pdf > Forget you ever heard of the term "balun" > > jim ab3cv > On Mon, Nov 5, 2012 at 2:37 PM, Don Wilhelm <[email protected]> wrote: >> Randy, >> >> That "balun" will not be very effective below 6 meters. The inductance >> of each winding is about 1000 nHy, which provides only 60 ohm choking >> impedance at 10 MHz. Sorry, but there are designs out there on the web >> that do not hold up to scrutiny. >> An effective balun must have a choking impedance of at least 5 times the >> feedpoint impedance, so for a 4:1 balun (200 ohms), the impedance must >> be 1000 ohms or more to be effective. >> >> 73, >> Don w3FPR >> >> On 11/5/2012 2:16 PM, Randy Moore wrote: >> > Can I divert slightly? I want to build this balun >> > (http://www.combotec.com/projects/balun14/balun14.html) >> > to use with a 40m delta loop from my K3/100, but the only PVC I have is >> > about 1.25" in diameter, not 40mm (1.5"). How do I compensate for the >> > smaller diameter? Google searches haven't been productive. >> > >> >> ______________________________________________________________ >> 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 >> > ______________________________________________________________ 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
