Recent articles Working a common mode scenario – G3TXQ Radcom May 2015 and Working a common mode scenario – G3TXQ Radcom May 2015 – voltage balun solution analysed a three terminal equivalent circuit for G3TXQ’s antenna system based on his measurements. Solutions were offered for the expected common mode current with no balun, with a medium impedance common mode choke (current balun) and an ideal voltage balun.
In summary, though G3TXQ expected the antenna system to have good balance, on measurement it was not all that good. The analysis showed that even a moderate impedance common mode choke reduced the common mode current Icm substantially more than no balun, or an ideal voltage balun.
This article performs similar analysis of the case of an ideal voltage balun applied to my own antenna system documented at Equivalent circuit of an antenna system at 3.6MHz.
In this article I will use notation consistent with (Schmidt nd).
Above is the equivalent circuit. Continue reading Working a common mode scenario – VK2OMD – voltage balun solution