Tech Articles

How a 1:1 Guanella-Balun (Current-Balun) Operates By Jerry Sodus, KM3K In the spirit of the hobby, I pass along what I have learned and don’t profess to know all the answers. 1. The primary reason for this work is to explain how a particular Transmission-Line-Transformer (TLT) known as a 1:1 Guanella-balun operates. Three other commonly used names to describe this balun are: “current-balun”, “isolation-balun”, and “choke-balun”; I’d suggest committing all four names to memory. The 1 …

With the advent of new technology in TV's, power supplies/chargers, new lighting products and other modern devices, there is an unfortunate downside from the electronic noise many of these items generate. To that end, we receive numerous emails and calls seeking a remedy to the ever increasing noise floor in our receivers. No question that baluns are one of the answers, but they are not the sole answer and in some cases are not the answer at all. To better understand this statement it is impo …

As with most equipment, we have become accustomed to determining our needs relative to power handling capability and the output power being used. However, when it comes to baluns and ununs, this rating or capability should not be used as a primary decision maker. The reasons for this are many and varied but here are a few of the most important.When a balun or unun is wound correctly, which is an important differentiator, a higher power rating will also mean a higher efficiency, low SWR and exc …

At least once a week we receive a request a for high ratio balun (6:1, 9:1, 12:1) to manage the transition from high impedance ladder line / open wire feedline to coax.  This is a common misconception and when using a loop, doublet or double extended Zep (and several others) for multiband operation will result in "operational frustration". This is because any type of open wire (including ladder line and twinlead) will present nearly the same complex impedance of the ante …