During the summer of 2013, I found time to run extensive common mode current (CMC) tests. The test involved many aspects, but one of them was to compare the single-core 4:1 Guanella to a dual-core 4:1 Guanella.
THE RESULTS WERE SHOCKING
AND CONFIRMED WHAT G3TXQ AND W8JI
HAVE MEASURED IN THE LAB.
A full description of my tests is found elsewhere on this web site.
Important for this discussion are the measured results comparing the two versions of the 4:1 Guanella.
A 4:1 Guanella wound on a single toroid core
IS NOT A BALUN.
NOT EVEN CLOSE!
I have not finished analyzing all of the data and summarizing all of my conclusions, but the results of the comparison of the two versions of the 4:1 Guanella are shown here:
Note: There is no return-link on that page. Use your browser's "Back" button to return here, or simply go to the menu at the top of the page, click on "Balun Stuff" and then "Bad Baluns".