On 8/30/2011 10:30 AM, ZR wrote: > Did you open up a Cushcraft balun to discover that method? I believe > some other companies do similar and Teflon wire is used so it doesnt > char as does THNN.
There are baluns and there are common mode chokes. I'm talking about common mode chokes. Some so-called "current baluns" are really common mode chokes. Some baluns are wired as auto-transformers, so they depend on flux coupling through the core to transform the impedance. More important, the core sees ALL of the transmitter's power. A common mode choke sees ONLY the common mode voltage/current, which, if the antenna is reasonably well balanced, is a tiny fraction of the transmitter power. This makes common mode chokes FAR less subject to overheating than a balun operating as a transformer. 73, Jim Brown K9YC _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
