Wow! Great illustration of the balun transformation. When at first I saw 3 channels + math oscilloscope traces on the screen, I knew it was going to be good. Sadly, there are too many people who don’t really understand these concepts out in the internet presenting hocus-pocus explanations that further confuse newcomers. I’m going to scan your channel’s video library in the hopes that you’ve dug deeper into the subject. Thanks and 73s!
I have only just discovered your channel, have played with baluns a lot the last 4 or 5 years. They are deceptive in looking simple... Without thinking too hard (or thoroughly) it looks almost as though the transmission line effects are working against you as you go up in frequency. (I really need to think this over). I have tried the 4:1 with separate cores as per your illustration but ended up asking myself why. It looks like a good idea though. To be honest I would be concerned about a 1dB loss, not for the usual reasons but because at high power that is a lot of heat to manage... Like you I think PTFE insulated wire is optimal (the conductors are silver plated too) Something I was going to try though is to put the windings through silicon tubing to reduce interwinding capacitance, though not sure if this will work. My conclusion so far is that common mode chokes work for me but that it is difficult to get high common mode impedance 160-10m from just one. With a total of 10 FT240 series cores the existing effort is not very economical to reproduce! 73
Hi Mark. Here's my uninformed two pennies worth (less value than a conker). I'm wondering if there's some weird capacitance floating about (between the windings?). If there's capacitance you'd have a potential RC circuit that could shift phases?? A random capacitance could also introduce an LC network ... the larger amplitude at 30MHz sorta implies resonance. Is it possible to get a dip meter inside the commercial balun? And these thoughts are probably bollocks so happy to be corrected in the spirit of learning.
It would be good to get some debate going here about what others think is going on. I'm going to re-make the commercial balun with a known toroid and see if that makes any difference. I wonder if the toroid is not what it claims to be?
As a beginner I find baluns the most confusing subject in ham radio! I'm really looking forward to seeing the re-make of the balun especially the test rig.. It seems as the word/device 'balun' seems to take on several jobs. For instance, a) the balanced to unbalanced transformation; then b) the rejection of common mode signals; then c) impedance transformations. My knowledge of electronics is limited and I'd like to see practical demonstrations of the various 'balun' functions - looking at you! All the best Kevin M0XYM
Wow! Great illustration of the balun transformation. When at first I saw 3 channels + math oscilloscope traces on the screen, I knew it was going to be good. Sadly, there are too many people who don’t really understand these concepts out in the internet presenting hocus-pocus explanations that further confuse newcomers. I’m going to scan your channel’s video library in the hopes that you’ve dug deeper into the subject. Thanks and 73s!
I have only just discovered your channel, have played with baluns a lot the last 4 or 5 years. They are deceptive in looking simple... Without thinking too hard (or thoroughly) it looks almost as though the transmission line effects are working against you as you go up in frequency. (I really need to think this over). I have tried the 4:1 with separate cores as per your illustration but ended up asking myself why. It looks like a good idea though. To be honest I would be concerned about a 1dB loss, not for the usual reasons but because at high power that is a lot of heat to manage... Like you I think PTFE insulated wire is optimal (the conductors are silver plated too) Something I was going to try though is to put the windings through silicon tubing to reduce interwinding capacitance, though not sure if this will work. My conclusion so far is that common mode chokes work for me but that it is difficult to get high common mode impedance 160-10m from just one. With a total of 10 FT240 series cores the existing effort is not very economical to reproduce! 73
Hi Mark. Here's my uninformed two pennies worth (less value than a conker). I'm wondering if there's some weird capacitance floating about (between the windings?). If there's capacitance you'd have a potential RC circuit that could shift phases?? A random capacitance could also introduce an LC network ... the larger amplitude at 30MHz sorta implies resonance. Is it possible to get a dip meter inside the commercial balun? And these thoughts are probably bollocks so happy to be corrected in the spirit of learning.
It would be good to get some debate going here about what others think is going on. I'm going to re-make the commercial balun with a known toroid and see if that makes any difference. I wonder if the toroid is not what it claims to be?
As a beginner I find baluns the most confusing subject in ham radio! I'm really looking forward to seeing the re-make of the balun especially the test rig.. It seems as the word/device 'balun' seems to take on several jobs. For instance, a) the balanced to unbalanced transformation; then b) the rejection of common mode signals; then c) impedance transformations. My knowledge of electronics is limited and I'd like to see practical demonstrations of the various 'balun' functions - looking at you! All the best Kevin M0XYM
3 bob and a conga??
Kool, Black magic!!!! from G1ORP
90 degrees ?? looks more like 180
How stupid of me - brain fade I think. Indeed I mean 180 degrees!