I just wound a balun nearly identical to the one you tested and installed it at the feed to my G5RV jr. I have a 100 ft RG8 coax. The result was a dramatic reduction in electrical noise. I was very impressed. I can now use 80m. Noise has just about gone away! Thanks.
Hi Joe, The commercial balun is a 'ferrite bead' design where they take a length of coax and put many ferrite beads on it (I've seen as many as 51 beads on some designs). I plan to do a video on testing things like baluns and ununs soon! Stu AG6AG
I did the exact same thing as you except with a RG-8x wrapped 43 toroid (total cost $20) vs the MFJ-915 RF isolator (retail $55) the best I could get was -18 db on the MFJ but the toroid was around -28. The difference of wrapping a toroid vs cramming as many ferrite beads into a PVC pipe.
It's funny, the expectations some have, when coming across a random video ! As if it was made for them ? And then when it doesn't turn out to fit their whim, they complain, rather rudely I might add ! Thanks for taking your time, and honestly sharing your results ! As for many of us, this is still Hocus pocus ! Too....thanks to your XYL keeping you focused !! Hi ! '73 !!
Thanks Sleeve, The results are a bit surprising, but the "Commercial" Balun uses Farrite Beads and not a toroid. Construction really makes a difference. Stu AG6AG
Hi Sleeve, Boy, is that a loaded question! So the short answer is that they both do the job, but your choice of why you use one or the other leads to a very long conversation. The thing about a toroid is that every time the wire goes through the center of the toroid, the affect multiplies. There are 24 paths through the center, so the effective comparison to a bead would be that you would need to have 576 beads to get the same choke factor. Yea, I know, sounds like a lot, but the reality is 24^2 is the math. However, with each time you go through a toroid, you reduce the wattage it will handle. This is due to the heat factor. The act of AC going through the wires multiplies the heat that the toroid develops. That is about as short an answer as I can come up with... Stu AG6AG
@@AG6AG Thanks Stu ! Very interesting, and not that I've studied this by any means, but I have never heard that. Wow ! That is really remarkable ! Just goes to show you, how easily one can be fooled into believing their efforts were enough, when in fact it likely falls short of their intentions ! Not that you'd be interested, and not to turn this into a forum, but I can't help to wonder about what kind of job the ugly Balun does ? I once read a fellows take that they too can be misleading, as to the number of turns and at what frequency. Have you ever wound up some ugly Baluns and tested those ? Thanks again for your time, but this is so intriguing, at least to me....Hi !
Hi Sleeve, I've not done a lot of testing with the ugly baluns. Mostly because of the DB loss over the length of coax you need to make the windings. That said, chokes for the most part work the same way. The use the field that is created by wires running next to each other to act as a filter to curtain frequencies. The commercial and home made balun we tested in the video are using the toroids to interfere with the common mode waves traveling through the wire where the ugly balun uses those same waves to create interference and "choke" of the common mode on the outside of the coax. The ugly balun is basically an air wound inductor interfering with itself... At least that's the easiest way to explain it. Stu AG6AG
Hi Robert, Probably not as by the time you calculate labor in to the mix, it just isn't a viable product unless you were making it at scale... That said, from a difficulty level, they are easy to make yourself. Stu AG6AG
Providing that the connections are stable and clean, it should not make a large difference, but there are times that jiggling the connections tell a story. Stu AG6AG
The 31 has a broader frequency range then the 43, but a lower heat range. Since we are talking about a 1:1 it should not build anywhere close to same heat as a 4:1 or 9:1. But a 43 would work as well for HF. Stu AG6AG
The one thing that I was looking for in this video was how to calibrate my in order to test my ugly balun and that is the one part that you skipped or rather fast forwarded through. Thanks for not helping.
Hi Bryan, Sorry that the fast forward made things more difficult for you. Calibrating a VNA is pretty much the same regardless of what you are testing. The goal is to calibrate with all the test cables in the circuit that will be used in the actual test. In my case I had two cables with alligator clips and basically ran a calibration with those attached to the VNA so there characteristics would ignored during the test. So the real answer is regardless of the tests you are doing, always try to keep test rig cabling in play when calibrating. Stu AG6AG
I just wound a balun nearly identical to the one you tested and installed it at the feed to my G5RV jr. I have a 100 ft RG8 coax. The result was a dramatic reduction in electrical noise. I was very impressed. I can now use 80m. Noise has just about gone away! Thanks.
Hi Charles,
Great news! I've been very happy with mine as well.
Thanks for reaching out!
Stu
AG6AG
Way to throw the XYL under the bus!! You rock! Thanks for showing us how to test these!
Very good. It would be interesting to compare the construction of the commercial balun to your homemade balun.
Hi Joe,
The commercial balun is a 'ferrite bead' design where they take a length of coax and put many ferrite beads on it (I've seen as many as 51 beads on some designs). I plan to do a video on testing things like baluns and ununs soon!
Stu
AG6AG
I did the exact same thing as you except with a RG-8x wrapped 43 toroid (total cost $20) vs the MFJ-915 RF isolator (retail $55) the best I could get was -18 db on the MFJ but the toroid was around -28. The difference of wrapping a toroid vs cramming as many ferrite beads into a PVC pipe.
It's funny, the expectations some have, when coming across a random video !
As if it was made for them ?
And then when it doesn't turn out to fit their whim, they complain, rather rudely I might add !
Thanks for taking your time, and honestly sharing your results !
As for many of us, this is still Hocus pocus !
Too....thanks to your XYL keeping you focused !!
Hi !
'73 !!
Thanks Sleeve,
The results are a bit surprising, but the "Commercial" Balun uses Farrite Beads and not a toroid. Construction really makes a difference.
Stu
AG6AG
@@AG6AG
You're welcome !
But now the question begs, from your experience do the beads always take a back seat to a Toroid ?
Just a curiosity .
Tnx !
Hi Sleeve,
Boy, is that a loaded question! So the short answer is that they both do the job, but your choice of why you use one or the other leads to a very long conversation.
The thing about a toroid is that every time the wire goes through the center of the toroid, the affect multiplies. There are 24 paths through the center, so the effective comparison to a bead would be that you would need to have 576 beads to get the same choke factor. Yea, I know, sounds like a lot, but the reality is 24^2 is the math.
However, with each time you go through a toroid, you reduce the wattage it will handle. This is due to the heat factor. The act of AC going through the wires multiplies the heat that the toroid develops.
That is about as short an answer as I can come up with...
Stu
AG6AG
@@AG6AG
Thanks Stu !
Very interesting, and not that I've studied this by any means, but I have never heard that.
Wow !
That is really remarkable !
Just goes to show you, how easily one can be fooled into believing their efforts were enough, when in fact it likely falls short of their intentions !
Not that you'd be interested, and not to turn this into a forum, but I can't help to wonder about what kind of job the ugly Balun does ?
I once read a fellows take that they too can be misleading, as to the number of turns and at what frequency.
Have you ever wound up some ugly Baluns and tested those ?
Thanks again for your time, but this is so intriguing, at least to me....Hi !
Hi Sleeve,
I've not done a lot of testing with the ugly baluns. Mostly because of the DB loss over the length of coax you need to make the windings. That said, chokes for the most part work the same way. The use the field that is created by wires running next to each other to act as a filter to curtain frequencies. The commercial and home made balun we tested in the video are using the toroids to interfere with the common mode waves traveling through the wire where the ugly balun uses those same waves to create interference and "choke" of the common mode on the outside of the coax. The ugly balun is basically an air wound inductor interfering with itself...
At least that's the easiest way to explain it.
Stu
AG6AG
Thanks - interesting and helpful. I have some toroids that I plan to wind, and this is great info.
Glad it was helpful!
Stu
AG6AG
Stu, when are you going to manufacture the balun commercially?
Hi Robert,
Probably not as by the time you calculate labor in to the mix, it just isn't a viable product unless you were making it at scale... That said, from a difficulty level, they are easy to make yourself.
Stu
AG6AG
I think that by making it yourself you are not saving money, but learning and enjoying.
Wouldn't it be much more accurate test by soldering the resistors and wires instead of the alligator clips?
Providing that the connections are stable and clean, it should not make a large difference, but there are times that jiggling the connections tell a story.
Stu
AG6AG
Would a 43 torroid be better?
The 31 has a broader frequency range then the 43, but a lower heat range. Since we are talking about a 1:1 it should not build anywhere close to same heat as a 4:1 or 9:1. But a 43 would work as well for HF.
Stu
AG6AG
The one thing that I was looking for in this video was how to calibrate my in order to test my ugly balun and that is the one part that you skipped or rather fast forwarded through. Thanks for not helping.
Hi Bryan,
Sorry that the fast forward made things more difficult for you. Calibrating a VNA is pretty much the same regardless of what you are testing. The goal is to calibrate with all the test cables in the circuit that will be used in the actual test. In my case I had two cables with alligator clips and basically ran a calibration with those attached to the VNA so there characteristics would ignored during the test.
So the real answer is regardless of the tests you are doing, always try to keep test rig cabling in play when calibrating.
Stu
AG6AG
DUDE!! Stop saying "GO AHEAD AND"! Like 50 times? COME ON. Sweet Jesus, drives me crazy! That is such a lazy and amateur way to present yourself.
Noted!
LOL! @@AG6AG
Very well done Stu! Easy to understand and a great presentation style! Good job on doing your homework! 73 de W3BWG
Glad you enjoyed it!
Stu
AG6AG