Your description of the Choke Balun was spot on, regardless of how you say it. If your antenna system is a victim of CMC, then it is (RF) unbalanced and needs a Balun Choke. The RF Choke balances the unbalanced element (generally coax shield) of your antenna system by choking off the CMC. Stray RF is for LIDs. I purchased the LDG 1:1 Choke Unun (still a choke balun in my opinion if it actually worked by removing CMC) but all it did was give me a "free" SWR boost. Time to roll my own. Thanks for the ALWAYS informative video.
I noticed the same thing with the LDG 1:1, though if I put it at the antenna end of the coax it did help with common mode. I swapped it out with two CMC chokes using a meter-long RG-58 jumper and two 240-31 toroids. No more RF in the shack making my computer's mouse cursor freeze when I transmitted on FT8. (Yes, every cable connected to my computer's also choked, but I think I was getting RF radiating from the nearby coax's shield, and the computer, a Beelink U59 mini PC, just has a plastic case.) And my SWR's under 3:1 on every HF band and 6 meters as measured at the shack end of the coax, easily tuned by my radio's internal tuner.
Great job Ape! My thought on the dip or notch is its a factor of the number of turns on the core. My guess is is you change the number of turns it will move the dig up or down in frequency. Just as thought. 73
As the wire being used in the test is parallel to another wire separated by the insulation, there may also be a capacitive element at play as well making a resonant circuit. As a side note, the choke made with the wire would be a "Transmission Line" choke with a nominal impedance dependent on the wire diameter and the spacing between the wires, probably around 100 ohms where the one made of coax will be 50 ohms.
Excellent demo on the 2 Rf "Chokes" !! .....The mentioned high end "Dip" is Real & Probably the Real critical "Self Resonance Frequency (SRF) max Attenuation Measurement where the Parasitic capacitance Parallels with the obvious Inductance Winding & produces a specific Frequency Max impedance Tank Circuit....Usable Choke application Freqs are usually Below the SRF Frequency.....Obviously, Vhf & Uhf applications Need the "Dip" to be Much Higher than your particular Demo example & specific Core material & winding Turns probably affect this SRF effect.....Thx for demo !!
When you tested the coax version, did you connect the coax shield to the NanoVNA or the center conductor to the NanoVNA? You didn't show this in the video. It is my understanding that, common mode travels along the shield of the coax.
I bypass the shield. You only want current on either the shield or the center conductor for this test. The role of the choke is to attenuate unbalanced current. When you have equal and opposing currents on two conductors they cancel out i.e. balanced.
Is the dip self resonance with interwinding resonance against the inductance from the choke? Would explain why the coax had it lower in frequency, because it has a larger diameter.
Hey Ape love yours vids. I would also test how each choke affects SWR. Twin wire characteristic impedance often is not 50ohm depending on spacing between the wires. Cheers Lance VK6LK
You can do that, in the past when I tested I did get better performance from the toroid. That said bead and toroid composition and number of beads / windings will make a difference.
@kinApe Call it what it is. teaching or pissing. You call it a balun. If you are going to use that philosophy, it should be unun. But, it's a choke Otherwise a nice video. :)
Cool. Just curious if there is much insertion loss difference between these two… and I wonder if insertion loss varies depending if it’s well matched or if its high SWR (as a result of differences in impedance of the load vs characteristic impedance of the line/coax)? I am considering using copper zipline for the bifilar windings for a project.
@ornthopterindia, not necessarily so, sir. Controlling the 2 wire impedance can be finicky, yes. But impedance depends on wire size, insulation and spacing. For winding on a toroidal as a transmission line, 25 to 200 ohms Z is achievable.
that was great. with that bump in attenuation may be the core . that frequency not getting threw. I get that bump making coax chokes as well . just wound some DC chokes today. same torrid just #10 AWG OFC zip cord DC chokes you can stack windings . those work very good for blocking RF on DC power leads . like solar MPPT controllers and DC to inverters. with DC choking using a cap across each side even a electrolytic will take low frequency off DC line. like alternator noise which is around a few KHZ . DC to DC converters ETC. 73's
Is the balun with copper wire wound wrong? Shouldn't the wire that crosses over half way go through the toriod then be wound in the opposite direction? That is the way it is usually done. It looks like you did it the right way with the coax balun
you should to use the shield of the coax because there are the both sides of the skin RF effect.. also, to have tested myself many variations, the wired methods don’t give a nice SWR with a 50 ohms non inductive load at the end.. all my good tests (isolation, loss and SWR) have been done using 50 ohms coax (any type of 50 ohms coax work well).. note that i only use the mix #43 (i have no interest for the #31 which is too bad in the upper HF area)..
I have found that that the bifilar wound types actually still transform impedance. Sweep that baby with a 50 ohm dummy load and you will see the SWR go up as frequency increases. Almost always a coax wound choke, specific to the frequency used, is the correct choice unless indeed you are trying to transform impedances. A different winding method is required to give the choke a flat swr if using wire. I have seen friends use those cheap amazon bifilar wound chokes and it turns their dipole into a multiband ALE type military antenna with a sweep that shows under 3:1 across the whole hf spectrum! Maybe ok, but not really what is being advertised! lol
The coax choke balun only attenuates current on the outer shield and maintains the 50 ohm characteristic impedance of the transmission line. The bifillar wound choke depending on the wire gauge and wire separation distance may not. The bifillar wound choke is more temperamental regarding the core material due to the fact that it is working as a transformer with only differential mode currents flowing, whereas the coax choke only works on common mode currents flowing on the outside of the braid. The common mode coaxial choke is therefore inert to the transmission line and behaves as if it is not even there with only the extra length of coax used to construct it as an attenuation loss. The core material used to make one is therefore not critical in regards to differential (normal mode) of operation however the choice of a material that has a high impedance to the frequency being used is advantageous.
Entertaining video. I personally avoid calling this 1:1 if it is not configured as a transformer. The gauge of the coax inner conductor and separation from the core vs the other solid copper wire may cause a difference in impedance performance.
Call it whatever you like! As long as it suppresses common mode current, who cares. I would like to see you test an "ugly" balun (1:1 choke balun: ~21' of coax close wound on a 5" form).
"Don't watch, I don't care" 😂 Don't upset Mr Ape, people! I got me a bunch of 31 mix toe-roids to make some chokes that I seen you do in your videos. That's what I call them because I can visualise Mr Ape "choking" some of the commenters!😂
Right. I was watching a video where an "expert" was explaining OCFD. He was explaining how you needed a 4:1 Balun because the antenna was "balanced" and the coax was "unbalanced". He seemed pretty convincing... lol.
When you show people how to wind a bi-filar CMC with enameled magnet wire you're inviting any little scrape of the insulator to cause an RF short (and increasingly terrible SWR) between the two filaments because you have the full voltage across them. The symptoms are an OK SWR at low power, then the start of an arc at medium power which then burns more insulation away to rapidly deteriorate SWR, even at lower power levels. BAD IDEA! ALWAYS use properly insulated (eg-PTFE) wire ESPECIALLY when winding in a bi-filar fashion. 73-The Antenna Whisperer K7RAW
I appriceate you taking the time to test things like this it saves me a lot of trial and error.
Hey Ghost, glad you like the videos. I just like testing stuff and hopefully it helps others out. Thanks for watching 👍
@@TheSmokinApe I will check that out! Thanks!
Outstanding job Ape bro!
Much appreciated🍻
There you go again you keep answering my questions!
Haha, thanks for watching Dave 👍
Your description of the Choke Balun was spot on, regardless of how you say it. If your antenna system is a victim of CMC, then it is (RF) unbalanced and needs a Balun Choke. The RF Choke balances the unbalanced element (generally coax shield) of your antenna system by choking off the CMC. Stray RF is for LIDs.
I purchased the LDG 1:1 Choke Unun (still a choke balun in my opinion if it actually worked by removing CMC) but all it did was give me a "free" SWR boost. Time to roll my own. Thanks for the ALWAYS informative video.
Thanks Norrin, I appreciate the comment!
I noticed the same thing with the LDG 1:1, though if I put it at the antenna end of the coax it did help with common mode. I swapped it out with two CMC chokes using a meter-long RG-58 jumper and two 240-31 toroids. No more RF in the shack making my computer's mouse cursor freeze when I transmitted on FT8. (Yes, every cable connected to my computer's also choked, but I think I was getting RF radiating from the nearby coax's shield, and the computer, a Beelink U59 mini PC, just has a plastic case.) And my SWR's under 3:1 on every HF band and 6 meters as measured at the shack end of the coax, easily tuned by my radio's internal tuner.
Thanks Ape, That was perfect. I've had that question on my mind for sometime now.
Glad it was helpful TJ, thanks for watching 👍
Great job Ape! My thought on the dip or notch is its a factor of the number of turns on the core. My guess is is you change the number of turns it will move the dig up or down in frequency. Just as thought. 73
Hey Jeff, I do think that it has to do with the core / wining being resonate which would follow your assumption.
As the wire being used in the test is parallel to another wire separated by the insulation, there may also be a capacitive element at play as well making a resonant circuit.
As a side note, the choke made with the wire would be a "Transmission Line" choke with a nominal impedance dependent on the wire diameter and the spacing between the wires, probably around 100 ohms where the one made of coax will be 50 ohms.
Keep it up Ape, I'm watching 👍
Thanks Skeeter 👍
Excellent demo on the 2 Rf "Chokes" !! .....The mentioned high end "Dip" is Real & Probably the Real critical "Self Resonance Frequency (SRF) max Attenuation Measurement where the Parasitic capacitance Parallels with the obvious Inductance Winding & produces a specific Frequency Max impedance Tank Circuit....Usable Choke application Freqs are usually Below the SRF Frequency.....Obviously, Vhf & Uhf applications Need the "Dip" to be Much Higher than your particular Demo example & specific Core material & winding Turns probably affect this SRF effect.....Thx for demo !!
When you tested the coax version, did you connect the coax shield to the NanoVNA or the center conductor to the NanoVNA? You didn't show this in the video. It is my understanding that, common mode travels along the shield of the coax.
I bypass the shield. You only want current on either the shield or the center conductor for this test. The role of the choke is to attenuate unbalanced current. When you have equal and opposing currents on two conductors they cancel out i.e. balanced.
I know this is an old video, but what is the insertion loss of both?
Insertion loss was very low, less than a db
I hate rude ass people. You just keep doing what you’re doing. Good job Ape
Thanks Steven
I figured the one that allowed the wire to be closer to the roid would be best. But it surprised me on the lower bands.
I was betting on the Coaxial being better 🤔
Great Video Ape! Thank You!!!
Thanks for watching Freddie 👍
Always interesting. Dean AF6MC
Thanks Dean 👍
Well done.
Thanks for checking it out Thump 👍
Does anyone ever use toroids of different mixes (either in series or together) to address CMC at both 80m and 6m?
I am sure some do, but I don't.
So type 31 for the 1:1 's . Gotcha thank the jankey test leads for us
lol, yeah use the 31s 👍
Is the dip self resonance with interwinding resonance against the inductance from the choke? Would explain why the coax had it lower in frequency, because it has a larger diameter.
I think you may be on to something there, thanks man!
Hey Ape love yours vids. I would also test how each choke affects SWR. Twin wire characteristic impedance often is not 50ohm depending on spacing between the wires.
Cheers Lance VK6LK
That's a pretty good point Lance, maybe a future video. Thanks for watching!
One more thing - clip on ferrite beads. How does, say, a string of 8 or 9 of these beads on a piece of coax perform in comparison? Do they work?
You can do that, in the past when I tested I did get better performance from the toroid. That said bead and toroid composition and number of beads / windings will make a difference.
Next question. Does twisting the bi-filer wires versus having them parallel (as in your experiment) make a difference?
Hey REK, it does however I am not sure you would notice. The relationsip in terms of distance between the bifilar wires does change impedance.
"Don't watch, I don't care." Dude I love it. Great explanation.
lol, thanks Carlos 🍻
@kinApe Call it what it is. teaching or pissing. You call it a balun. If you are going to use that philosophy, it should be unun. But, it's a choke Otherwise a nice video. :)
Cool. Just curious if there is much insertion loss difference between these two… and I wonder if insertion loss varies depending if it’s well matched or if its high SWR (as a result of differences in impedance of the load vs characteristic impedance of the line/coax)? I am considering using copper zipline for the bifilar windings for a project.
I did measure insertion loss but do not recall the results, sorry man 👍
👍Thank you sir.Twin wire has higher impedance than coaxial cable.
That's a pretty good point and perhaps content for a future video... thanks for watching!
@ornthopterindia, not necessarily so, sir. Controlling the 2 wire impedance can be finicky, yes. But impedance depends on wire size, insulation and spacing. For winding on a toroidal as a transmission line, 25 to 200 ohms Z is achievable.
What coax cable you prefer
For winding this core. Or do you prefer the 18gauge teflon wire
I do rg58 and that’s what I mostly use
that was great. with that bump in attenuation may be the core . that frequency not getting threw. I get that bump making coax chokes as well . just wound some DC chokes today. same torrid just #10 AWG OFC zip cord DC chokes you can stack windings . those work very good for blocking RF on DC power leads . like solar MPPT controllers and DC to inverters. with DC choking using a cap across each side even a electrolytic will take low frequency off DC line. like alternator noise which is around a few KHZ . DC to DC converters ETC. 73's
Hey Robert, I think you are right about the core.
Any chance you have metal underneath your work surface causing that dip?
there's probably stuff all around that could do it, the current general consensus is that it is the core resonate point.
Interesting. I am not getting the dip with my mix 31 and 43 using 13 turns of RG/58.
@@rfburns3472 that is interesting, I’ll test with some non-janky leads
Looks like I need to buy some magnet wire and/or make me some janky test leads and check my choke. Good stuff.
Get after it son!
It'd be interesting to compare type 31 with type 43 say DG0SA/sk's design. The instructions are in German, but I found them easy to parse.
I recently compared a 31 to a K-type with the DG0SA design, I can do 43 vs 31.
@TheSmokinApe cool! 43 is what I intended to type. Thanks!
Is the balun with copper wire wound wrong? Shouldn't the wire that crosses over half way go through the toriod then be wound in the opposite direction? That is the way it is usually done. It looks like you did it the right way with the coax balun
It's correctly done
you should to use the shield of the coax because there are the both sides of the skin RF effect.. also, to have tested myself many variations, the wired methods don’t give a nice SWR with a 50 ohms non inductive load at the end.. all my good tests (isolation, loss and SWR) have been done using 50 ohms coax (any type of 50 ohms coax work well).. note that i only use the mix #43 (i have no interest for the #31 which is too bad in the upper HF area)..
Hey Marcus, thanks for the comment!
I have found that that the bifilar wound types actually still transform impedance. Sweep that baby with a 50 ohm dummy load and you will see the SWR go up as frequency increases. Almost always a coax wound choke, specific to the frequency used, is the correct choice unless indeed you are trying to transform impedances. A different winding method is required to give the choke a flat swr if using wire. I have seen friends use those cheap amazon bifilar wound chokes and it turns their dipole into a multiband ALE type military antenna with a sweep that shows under 3:1 across the whole hf spectrum! Maybe ok, but not really what is being advertised! lol
Hey Dylan, thanks for the info and for watching 👍
Doesn't Balun term comes from BALanced-UNbalanced?
yes
The coax choke balun only attenuates current on the outer shield and maintains the 50 ohm characteristic impedance of the transmission line.
The bifillar wound choke depending on the wire gauge and wire separation distance may not.
The bifillar wound choke is more temperamental regarding the core material due to the fact that it is working as a transformer with only differential mode currents flowing, whereas the coax choke only works on common mode currents flowing on the outside of the braid.
The common mode coaxial choke is therefore inert to the transmission line and behaves as if it is not even there with only the extra length of coax used to construct it as an attenuation loss. The core material used to make one is therefore not critical in regards to differential (normal mode) of operation however the choice of a material that has a high impedance to the frequency being used is advantageous.
I got alot out of this one. Thanks
Glad it was helpful, thanks for watching bro!
Entertaining video.
I personally avoid calling this 1:1 if it is not configured as a transformer.
The gauge of the coax inner conductor and separation from the core vs the other solid copper wire may cause a difference in impedance performance.
I think I agree on all points, thanks for watching!
Call it whatever you like! As long as it suppresses common mode current, who cares. I would like to see you test an "ugly" balun (1:1 choke balun: ~21' of coax close wound on a 5" form).
Lordy, that ugly balun seems like a PITA
Great video! But I can watch anymore because you used the wrong color of zip tie… or something like that😂
lol
Remember when Mosley told everyone just to wrap their coax 6 times into a loop. Lol wonder how that looks on 10-20
lol. I am not a fan of the ugly balun...
"Don't watch, I don't care" 😂
Don't upset Mr Ape, people!
I got me a bunch of 31 mix toe-roids to make some chokes that I seen you do in your videos.
That's what I call them because I can visualise Mr Ape "choking" some of the commenters!😂
Hey Don. By far most comments are positive and I even enjoy some of the critical comments. It's just a few, well one in particular, that made me mad.
The new technical catch phrase in ham radio. Janky leads.😅
Exactly!
Now we need another shootout: bifilar CMC VS bisectional bifilar CMC 😅
lol, I’ll add it to the list 😳
@@TheSmokinApe don't sweat it
Some People even call a HF Transformer like a 9:1UNUN or a 49:1 a Balun. "Ouch"
Right. I was watching a video where an "expert" was explaining OCFD. He was explaining how you needed a 4:1 Balun because the antenna was "balanced" and the coax was "unbalanced". He seemed pretty convincing... lol.
"That's not a balun, that's a BAL-UN!!!!"
😅
😳 thanks for watching Allen 👍
When you show people how to wind a bi-filar CMC with enameled magnet wire you're inviting any little scrape of the insulator to cause an RF short (and increasingly terrible SWR) between the two filaments because you have the full voltage across them. The symptoms are an OK SWR at low power, then the start of an arc at medium power which then burns more insulation away to rapidly deteriorate SWR, even at lower power levels. BAD IDEA! ALWAYS use properly insulated (eg-PTFE) wire ESPECIALLY when winding in a bi-filar fashion. 73-The Antenna Whisperer K7RAW
Thanks TAW 👍
Why don't they call it UNBAL instead of BALUN? Then its purpose is almost self explanatory.
Dang it, they should!