I would be curious as to what you've found to be the most efficient transformer. I understand, or believe these type of antennas are considered a compromise antenna, but what "should" one use? I don't have a clue how to read or perform the tests that your doing to test for myself.
Can you show how you twisted the primary wires? I would like to see a diagram of how you wound the wire. This is very interesting to me because I have used a lot of the recommendations by the RU-vid and Facebook "experts" as you call them. Thanks for the help
Very interesting stuff! What would be also interesting to compare against 43 and 61 material. Another idea that I have never seen: Stack two different materials, e.g. 43 and 61 that could lower the losses in the lower and higher frequencies?
Have you tested the loss using type 61 cores, i am using FT140-61 for portable on 40 and 20m bands 65 feet wire, I did back to back tests and found the loss was very low, turns ratio 3-27 turns with a tap at 3 turns no cross over
Thank you for finally removing some of the BS ... pse do same comparison on 43 and 31 mixes. IMHO the crossover causes flux to oppose turns vs inductance. It prob equivalent to two inductors in series w the first 7 turns actually acting as an autoxfmr in series w an inductor. Is that possible Dunno ? Windings in opposite direction should oppose each others influence on the core. Pse ur comments?! I hv been testing an original wining 3 core 43 mix and it does allow tuning but also makes a good room heater at 500 w hihi 73 Paul de K2HZO
Well, the toroid core permeability for mix 52 is low, you need to stack 3 toroids together to have a good result. You can get 82-98% of efficiency from 80 to 10. If you use one Toroid - you are correct, it is not good
So you just commented here without actually watching the video. If you had watched, you would have seen it is a stack of 3, and you would see that your efficiency numbers are completely inaccurate.
@@evil_lair_electronics You are correct, my fault, sorry about that - I watched on my phone and skipped first few minutes by mistake. Strange, my test with 3 cores showed totally different story - much better than yours. My only guess is - either your cores were wrong (not really mix 52), or my test had a flaw...
@@polzovotel If you search youtube you will find others who have tested the 3 stack and also seen the unacceptable losses above 15 meters. Myantennas has previously published these measurements as well.
@@evil_lair_electronics As you always say at the end of your video - check for yourself ;) meaning I need to redo my tests again. Maybe I had a calibration issue with my VNA.... What core would you recommend for 40-10m, 100watt SSB ?
@@polzovotel I've seen the same results that Colin is seeing here, never found a better transformer to cover all of 160-10m. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Xe0wvbOQeok.html
