That's the point, as Don pointed out: "sufficient impedance". A normal rule of thumb is to have choking impedance 10X the line impedance. That's easy if you have a 50 Ohm line, such as the input to the tuner. It's quite a different story if the line impedance is 1000 or 2000 ohms, such as can happen on the output of the tuner feeding an "all band doublet" or similar antenna with open wire line.
Ron AC7AC -----Original Message----- On a previous post I included three links which if read would lead you to the conclusion that a common choke on the output of the "unbalanced" tuner of sufficient impedence would ensure that all of the current on the interior of the shield of the coax and on the center conductor would be present on the "balanced" line if the outside of the shield was prevented from carrying RF. That equal and opposite current present on the "balanced" line is what is desired. No transformer, balun, etc which would be suject to widely varying impedences from such a line is required. Just squirt the current in equal and opposite amounts and don't let it leak anywhere.... <-technical description... jim ab3cv ______________________________________________________________ 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
