Third part in the series…
Common mode current measurement
Direct measurement of common mode current in an antenna system is the best indicator or whether there is a common mode current problem.
In Common mode current and coaxial feed lines, I mentioned that common mode current is easily measured.
Continue reading Design / build project: Guanella 1:1 ‘tuner balun for HF’ – #3
Second part part in the series…
Common mode impedance
When baluns are used with open wire feed lines to wire antennas on HF, most commonly the main purpose is to suppress common mode current, to ensure that the current in one wire of the feed line is equal but opposite in direction to the other wire at that point.
Continue reading Design / build project: Guanella 1:1 ‘tuner balun’ for HF – #2
This is a project to design and build a Guanella 1:1 (current) balun for use on HF with wire antennas and an ATU.
For use with a tuner, the most important design criteria are:
- high voltage withstand;
- high common mode impedance;
- generous power handling given our 400W PEP limit, possibly 1kW in the future.
Continue reading Design / build project: Guanella 1:1 ‘tuner balun’ for HF – #1
I mentioned in my article WIA 4:1 current balun that the use of a single toroidal core in the above graphic compromises the balun. This article gives a simple, but more detailed explanation for the technically minded of why the shared magnetic circuit ruins the thing.
Continue reading WIA 4:1 current balun – further explanation
Under the heading “Wind your own balun “, the WIA’s “Your entry into amateur radio” 2nd ed (The Foundation licence manual) gives advice to newcomers on constructing a 4:1 Guanella balun, a current balun.
Continue reading WIA 4:1 current balun