How to test a 4 to 1 balun. Locate a NON INDUCTIVE (Carbon composition, for example) 200 ohm resistor and connect it directly across the output terminals of the balun. So it should cover 160m, 80m and 7 MHz bands. Testing a 4:1 balun with the nanovna. It is for this reason that I chose to not Oct 17, 2011 · When you have built your balun, you can test it by putting a pure-resistive load across the terminals and measuring the SWR across the spectrum you intend to use. While the 4:1 ratio is often referred to for the interface between T-Match network and a balanced antenna system it will often not be the ideal choice when very low impedances are encountered. I use this to test all my transformers that I build, you can put 24 Basic Balance Quality Test for Current Baluns A Guanella or current balun's functional quality can be evaluated by moving a ground (common with signal source) to points Test 1, Test 2, and Test 3 (figure 1) while watching voltages or currents in the load, or even by watching input SWR. For a 4:1 balun, that means a 200 ohm load (4*50=200). Sep 3, 2025 · Got good SWR match with 4:1 balun on bench test with NanoVNA from 1 -11 MHz. The final test is of course by connecting it to the feedline, between the ladder line and the short piece of coax!. It does give a 4:1 impedance transformation, but the "balanced" side isn't balanced. The SWR should be 1:1 across the spectrum. May 5, 2025 · Requiring a balun to feed a balanced feed line with an un-balanced T-Match network a 4:1 Ruthroff voltage balun design using a T200-2 Toroid core was selected. How do I test my 4:1 balun? A straightforward way to test a 4:1 balun is as follows: Disconnect the output side of the balun from your antenna or ladder line. Here’s a video showing the test of the balun I built: It looks good! It's a 4:1 but it's not a good one, and it's not exactly a "balun": it's an attempt to construct a 4:1 Guanella using only a single core, which doesn't actually work. 200 ohms across balun will match 50 ohms at the vna. czfl zhgm oengc ktad qavy ulnqanmk qpcxv ttdrp loqldw pmyrzyx