Watch the earlier three parts of this series first to get the complete overview PART 1: • #100 Balun PART 1: Bro... PART 2: • #101 Balun PART 2: Bal... PART 3: • #105 Balun PART 3: How...
Peter, I can't thank you enough for the 4-part video series. For my all-band, home brew open-wire feeder and 80 m loop, I needed to "tame" the impedance it presents across the HF spectrum. I "swept" the antenna, checked the data, and decided that 9:1 transformations would do what I wanted. So, last night I watched your 9:1 video and as you went along, I wound mine step-by-step. Then at the end of the video you stressed that a 1:1 current balun was required for CM attenuation (and balanced input to the 9:1) and so I watched the 1:1 build that you also provided and I built one as you described. Today and tonight, I performed a VNA sweep of the baluns to confirm performance and then placed them (interconnected) back-to-back into a CANTEX utility box (with SO-239 input & threaded-studs on the output). I tested the balun combo with my all-band antenna and on the HF bands at power levels up to 250W on all bands from 80m - 10m (fine tuning, of course, with a little help from the tuner). The baluns' performance was superb and transformed the wild impedance swings of the multi-band antenna transforming them to be within the performance specs of my matching network! I checked the "balance" on the feed line and it was ideal - far superior to the common 4:1 balun in many tuners. As a result of this two-day project, there is no more obvious signs of CMC and/or RF floating around the shack, and/or higher-than-normal noise levels. In conclusion, the balanced output of this new configuration works even better than my bare-bones Palstar BT-1500A, in my experience. THANK YOU for your contribution of time and effort. It's very much appreciated!! 73!!
Saw a comment from me that I wrote 7 yrs ago. Have had your common mode choke at the base of my hexbeam for what must be 7 yrs now. It has served me well. I have now removed it to try snap on ferrites no 31 instead of a torroid. Have now started to experience swr problems on 10m and 24megs. I am going to put the torroid one back. Anyway 7 yrs later, I am still returning to your videos for reference and an aid to my memory. I have nearly completed this 9:1 torroid, but I am putting two cores together to try to avoid heat. I am waiting for some ptfe wire to arrive for the common mode choke. I tried some cheaper silicon wire but found it was too fat to wind on the torroid. I am going to put these on a random wire antenna for the lower bands. I might use a 31 mix for the common mode because I want to get back on to top band. Up until last year, for top, 40 and 80, I just used a wire with the feeder wrapped around 4 stacked 240-43 torroids at the base of the mast, tuned at the atu in the shack. That worked well but came to grief in storms. Also I am thinking about the emf regulations so that is why am refering to your work. I will be able to put these torroids at the top of the mast, and hopefully I can avoid radiation from the feeder which now would be inside the regulation exclusion distance. Thanks again for the tuition Keith G0ODU
Keith, I hope you see this... I bought some PTFE & wasn't getting the results I expected. I used a potentiometer on one leg of the 1:1 CMC and found the match was 150 ohms!! I remembering separating feedline conductors increases impedance I realized the PTFE insulation was too thick. So I ordered more PTFE, with thinner insulation. It worked!! a little tweaking of the newly wound spacing got 100 ohm per side, and a nice 50 ohm with both in parallel. An interesting journey. Good luck with your new build! 73 de Noel ZL1NC
I am very grateful to Mr. Peter - TRX LAB - for the information that helped me solve this balun issue using the FT240-43 ferrite. I followed the guidance and managed to make my balun. I am very happy and impressed with the performance. Congratulations on the initiative and all the benevolence. 73 from this humble radio ham
I know I am just repeating what so many others are saying, but thanks you! Your balun series is the best series on the subject, anywhere. I am also one of the many really hoping you will make a 49:1 balun video. Fingers crossed. =)
For a 49:1 or 64:1 you would follow the same concept as you see done with this 9:1. The important idea is that the impedance match is equal to the square of the turns ratio. So, for a 9:1 match, the windings are 3:1. For a 49:1 match, you need a 7:1 turns ratio, and for a 64:1, you need a 8:1 turns ratio. The number of total turns on the high side of the coil doesn’t matter as long as it fits on the core, and is divisible (you can tap into it) by the ratio value that you need. So really, a 3:1 turns ratio can be a winding with 18 turns, tapped at 6 turns (1/3 of the total) and 12 turns (2/3 of the total) to get your inputs. The ends of that 18-turn coil would go to the antenna. With a 49:1 or 64:1 you would need either a larger core or smaller wire so that you could get 21 or 24 turns onto the core, tapped at 7 and 14 for the 49:1, or at 8 and 16 for the 64:1.
I find watching these videos is very relaxing and educational. They are so much better to spend time with instead of television or sports games or news. Thank you for the work you put into them for the benefit of us technicians in training around the world. I particularly enjoy watching your method and final solution.
Thanks Peter, I appreciate the effort you put into these videos, being new to HF I do prefer the "proper" engineering approach you use. I am following your examples and very much like to see the testing you do, no guesswork here, as it should be, well done. Best Regards.
I'm watching this series of videos for the second time because there is so much good stuff to learn, I need to watch it at least twice to take it all in. You have put a lot of work into this and I'm very grateful. I wonder how many people you have saved from radio interference and how many rigs you have saved from too higher SWR! Thank-you.
This is my second time watching as well. I recently completed a course for electricians, where I learned a lot about transformers, so watching it the second time really solidified my understanding. It also helps to draw the device out in a traditional schematic diagram form.
I tried this on a FT140-43 core and it worked great. SWR was under 1.25 over 3 to 30 MHz and it was pretty much flat. I also wound a more typical 3 wire 9:1 unun very carefully on the same core and it was much much worse, especially at the high frequency end. I used insulated 18 AWG wire because that's what I had and it still worked great. Thanks.
Yes the best and most detailed. You are truly the best teacher, I always learn things from you I have problems learning on my own. Wish I can come be your student.
I just wound it and it worked out well - I got less than 1.3:1 from 1 - 30 MHz. I'm thinking that the key points here are the even and maximal spacing of the windings, minimizing parasitic capacitance and keeping the leads short, minimizing stray inductance. I wound it on an FT240-43 core with 18 AWG wire (all I had, but I'm never going to be using it with more than 100W). I just wanted to thank you for the detailed instructions
Hi Peter. I'm completing a 9:1 Balun just like your video, however, with FT-140-43 toroid. In an initial analysis on NanoVNA, the SWR from 1.8 to 54 Mhz was practically between 1.0 to 1.3. As soon as I finish the balun, I'll be posting it on my UA-cam channel. 73 and God bless you.
Your Videos are great. I have learned a lot about toroids and setting up Baluns. Have you ever thought about doing a series on 49:1 Baluns /UNUNs for EFHW antennas?
Peter thank you for this very practical tutorial on using toroidal core auto transformers. You have provided me a eureka moment (actually several) in this part 4 video. The first is the method of adding friction to hold the windings in place, second is how to evenly space the turns using indexing, third placing the primary winding in the center of the coil to produce a balanced input and output, and fourthly but not finally, insight to calculating turn spacing. I do admit to having to watch the segment beginning at 19:50 three times as at first I thought these 8 turns were being wound in an opposition sense to the first 8. I will apply some of the techniques you present to constructing an auto transformer to match unbalanced 50 ohms to unbalanced 4000 ohms (end fed half-wave or a bisquare antenna). This will require a 9:1 turns ratio so my first attempt will be 3 turns for the 50 ohm port and 27 turns for the 4000 ohm port. I will test with an MFJ 259 analyser as that is what I have. Thanks again for both the instruction and inspiration.
Just made mine according to your excellent instructions. My miniVNA even measured slightly better SWR so I'm very pleased with it. Thanks a lot and 73 de ON7IR
so viele wundervolle Dinge in Deutschland von der Feinmechanik bis zur wunderschönen Landschaft! Peter, vielen Dank für dein Fachwissen und deine Bereitschaft, dieses Fachwissen mit dem Rest von uns zu teilen! Haben einen gesegneten Tag!
Wow, thanks Peter, I just finished my 9:1 transformer, by watching this vid step by step. Though not as neat as your job (yet), I get very similar SWR figures on my AA-200, excellent result. Thanks you so much! (73 GW4OKT)
hi peter great detail on baluns i have built the 9 to 1 and under test of 1 to 30 mhz the highest swr is 1.23 . best preformance of all the baluns i have built thanks again
Hi Peter, Awesome video. Very clear instructions. If followed, anyone can have a great preforming balun. I’m sure this series of videos will be referenced many times. Thanks 73
Peter, thank you for an excellent video. I am a subscriber and routinely use the information you provide to assist me with my projects. I just completed winding this balun. My testing showed a VSWR of 1.0x all the way up to 30 Mhz where the VSWR was 1.3. I used a ft-240 mix 61 core. The tips you provided with the dots and the cloth tape were very helpful.
Nice illustration of how to build a transformer. It would have been even better to see a traditional circuit diagram of the device. As far as I can tell, this is an auto transformer with input taps at 1/3 and 2/3 of the total winding, with outputs spanning the entire winding. So if I’m not mistaken, here we have two, 3T:1T auto transformers in this one device. And 3:1 turns ratio results in an impedance transformation which is the square of the turns. This really would be easier to visualize with a traditional schematic component drawing.
Hi Peter. Another great video series. you keep putting out some of the best vids out there. I will tell you one of my secrets for 9:1 Baluns. I use a t150-52 iron core with 10 or so turns. and is flat across all the hf bands You will find these in many switch mode power supply's. Green/blue toroid. and at 1/4 price. I haven't used these above 125 watts but they work for me. I also use some of my beldon 83336E stash I have. Keep up the great work!
Hello Peter, thank you for your very interesting videos. I particularly appreciated the BALUN series. I'd like to add my request for a 49:1 and 64:1 transformer's for end fed antennas tutorial.
I put together a 1:9 unun as per instructions here. When I tested it with a 448 ohm resistor chain, the VSWR was 1:1 to 1:2 from 1 to 30 MHz. Suffice to say, I am very happy. However, besides testing it, he doesn’t go into how it is supposed to be hooked up to an antenna system.
Wow, this is the best series on baluns and common mode attenuation i have ever seen. I have already built the 1:1 and the 4:1.(Wunderbar) The 9:1 is next, I would really like you to do a build of Wolfgang's the 6:1. Vielen Dank Peter fur diese Serie. Barnie M7PBX.
I'm sure that your RF transformer (mix 43 toroid?) has good performance, but SWR is not the right way to dimostrate it: you checked how much RF power is reflected back, but you don't know how much is provided at the secondary terminals. Also a dummy load shows a very good SWR but the whole power is converted into heat! So, measure the SWR with the secondary open and then with the secondary shorted: if your transformer has low losses, as I think, almost all the RF energy will be reflected back in both the tests (very very high SWR). For an insertion losses precise measurement connect also the secondary: connect it to the second port of the VNA with a 400 ohm resistor in series: measure the loss between one port and the other and divide it by nine (it is not necessary to explain why...). Even better if you make a second identical transformer: for this test connect the 450 ohm secondary of one to the secondary of the other, and the primaries to the two ports of the VNA. Measure the losses between the two ports and divide it by two. Let us know. 73s
Thank you for the very slow and complete explanation! ... Too bad you don't enable the subtitles!! My English is basic, and I can understand it by watching it 2 or 3 times... ! Well that's how I practice English!! Most baluns fail because of something as simple as the correct spacing of the turns! -Very well explained!! ..73 and DX's Enric, EA3FSU.😅
Peter once again another outstanding video, you seem to have the gift of being able to tie theory together with practical application. There was only one point that may need some clarification for the young players out there and that was the turns ratio vs impedance ratio. What you built was a 9:27 (or 1:3) autotransformer with the impedance transformation being the square of the turns ratio, hence the 1:9... Thanks again for sharing I look forward to your next video. 73
HELLO FROM GREECE..THANK YOU FOR THE DETAILED VIDEOS...PLEASE TELL ME HOW YOU DETERMINE THE POSITIVE AND NEGATIVE POINT FOR THE 50 OHM AND THE POSITIVE AND NEGATIVE POINT FOR THE 450 OHM ...REGARDS...
Excellent videos. Built a 1:1 current balun (with proper core materials) and works beautifully though only up to about 30MHz. No problem since I'm building a 20m dipole. Suggestion for a part 5 video: 49:1 transformer for half-wave end fed antenna. It would be interesting to compare your approach to the one i built. -73 VA3GLB
Vielen Dank, Ich bin neu bei Amatuerfunk HF. Meine Familie stammt ursprunglich aus Wien und ich lernr wirklich Deuctch. Ich Leben in den Vereinigten Staaten. Nochmals vielen Dank fur das Video.
This is an interesting design for 9:1. You're feeding the auto-transformer across the middle of the three windings, where most 9:1 UNUN feed across the 1st of the three. I wonder what the result is in a typical application using an end fed "random" wire where you ground the other 1/2 of the output? With the traditional design one connection is already at ground anyway because the coax shield is there. Not sure how it ends up with ground connected to two different places in this setup. I'll have to try it out - and great stuff as always Peter.
As always, great video. Enjoy your attention to accurate detailed workmanship. Does the type of insulation for example, THHN electrical wire insulation on 14awg solid matter in winding a balun lets say a 1:49, or some refer to as a 49:1 unun? Will it create resistance and change not only impedance in the balun, but wire length of 1/2 wave efhw. How would electrical wire using THHN insulation effect making a 49:1 unun and what would be the suggested distance between the outside of the windings of a 49:1 unun IF that type of wire is used?
Does the cloth tape also provide insulation - preventing the wire from shorting out through the toroid ? The enamel insulation on the wire seems unlikely to oppose the voltages involved ? Thanks for an excellent video.
@trxlab . Im building your 9/1 unun. I'l looking forward to launching a long wire over the Oak trees in my backyard. So, I would like to have 160m through 10m if possible and with all the talk about random wire antenna lengths, I believe I have room for 500+ feet wire lengths. do you have any ideas on wire lengths, is longer better and should I use ptfe or solid core and what gauge? Do you have a series on long wire antenna lengths? thank you for your time and I very much enjoy your series.
Again thank you for a great tutorial. May I ask please how then do we cut the long wire to resonance because the transformer wont let u see the antenna properties.
Instead of making the first solder joint you can just make the wire longer in the first place and wrap the second winding without having to solder more wire on.
Peter, excellent video series! I have referred my ham friends to you who I've inspired to DIY ununs/baluns. Question: you recommended PTFE wire for your 4:1 and 1:1 projects, yet in this 9:1 project you are using enameled (lacquered) wire, why is that? PTFE provides both superior heat and electrical resistance compared to enamel insulation, and in the case of an end fed random wire antenna that uses 9:1 transformer the voltage will be at its highest at the feed point, which can reach a high level (ditto for end fed half wave antenna that uses 49:1 transformer). The 4:1 and 1:1 balun project videos (I watched all those) you use PTFE wire in transformers that are typically used with center-fed dipoles or loops where feedpoint voltage is at its lowest (and current highest). It seems quite opposite recommended wire to me. With that said, I have typically used enameled wire for end-fed antenna transformers in QRP applications, which of course would be relatively low expected voltages, but here in this 9:1 you are talking about 800W and above? What say ye?
Die gleiche Kombi habe ich bei Wolfgang bestellt ( Bausatz , Mantelwellensperre und 9:1 ) funktioniert einwandfrei . Gut gemachtes Video , wie immer sehr ausfürlich . thumbs up ;-)
Dear Peter thanks for all valuable information given to this video series. Is it possible to attempt a 1:49 Balun for high power as well? Thank you in advance and please keep doing the really good work
Excellent presentation. I think it should be emphasized a bit more that the load resistors must be non-inductive. That may have been part of the issue with the SWR rising at higher frequencies. Thanks.
Would this be a good dummy load for 450 ohm? www.amazon.com/uxcell-Green-Aluminum-Housed-Resistor/dp/B008FZBLK0/ref=pd_lutyp_im_4_1?_encoding=UTF8&pd_rd_i=B008FZBLK0&pd_rd_r=121ZHFZMG06004CQ3MSB&pd_rd_w=jedWF&pd_rd_wg=xm5Xe&psc=1&refRID=121ZHFZMG06004CQ3MSB
a little sand paper action works well to remove the di electric insulation off of the transformer wire ... also why not use pvc coated / jacketed wire ? ?
Thanks for the video. Can you explain why you used three wires? Why can you not make 24 turns with one wire and simply tap the coax inner by soldering to turn 8? Isn't the magnetic field generated by the signal uniform throughout the ferrite core? Also why is this a 9:1 transformer if there are 3 x 8 turns. Why is it not 8:1?
Matt Haxx Hi - with this winding method we get 8 turns primary and 24 turns secondary, so a 3:1 turns ratio. The impedance is proportional to turns ratio squared, so 9:1 :) .
Thanks a lot for doing this informative video. But, I do have a question. Would someone please comment and diagram the 50 ohm and 450 ohm connections as they relate to signal and ground. I just want to make sure that I have the input and output connects made correctly. Thanks.
Danke dir fuels video. Habe gerade ein 9.1 gewickelt aber jetzt bleibt mir die frage welche der Anschlüsse ist der Strahler und welches der Counterpoise/ground ist. Hilfe bitte.😊
Peter, this is a Fantastic series indeed. Been a long time fan of your channel. I'd like to ask if the space between the two completed Baluns is crucial to be about ~3.5 cm as it is in your video, or could it be 0.5 cm ? I have a box that could house these two baluns at this smaller distance just fine, but I am worried if it will undermine it's performance. Thank you for your helpful reply in advance.
Excellent video...thank you. Peter, I have one question, how to hook up the two wires to a single longwire antenna? The HyEnd wire antenna has only the wire attachment to the balun box and no counterpoise, can this be duplicated with this transformer design?
TRX Bench I would be interested in building the 2:1 balun for the same reason. After watching the 4:1 balun video I think I figured it out but without proper test equipment I don't want to cooka radio to find out 😂. Thankyou for your video series
I'm looking to build an 18:1 Balun for a rhombic antenna. But can't find any info on google. How many turns is kind of confusing to me. Thank for all your teaching TRX Bench. Will be attentive to see if you show how to make a 18:1 balun. Cheers.
It seems like one of the main points is that you space the tri-filar windings as much as possible. Is this to keep the inter-winding capacitance to a minimum?
Thank you for this series - it is beyond excellent. Is there any detriment to using solid 14awg (~1.62mm) transistor wire for the 1:1 attenuator or the 4:1 transformer? I will be building 3x 1:1 attenuator, 1x 4:1 transformer, and 1x 9:1 transformer. If there is no negative effect, I would prefer to use the same wire for each component and am too inexperienced to identify a negative from using 14awg solid for the previous builds.
Peter - thank you for the excellent videos on making baluns. I would not have attempted this without your patient explanations and demonstrations. Two questions: 1) Is the PTFE wire for the 1:1 and 4:1 baluns solid or stranded? Does this make a difference? 2) How critical are the lengths of the wires that connect to the SO239 connectors? If the "hot" lead is shorter than the "screen" lead will that make a difference in the SWR? Mark, W9MS
Thank you Mark, the wire is PTFE and stranded. Under heavy load the balun cpild get hot so PTFE is a good idea. The wires should be as short as possible but it is not to critical if screen is a bit longer... Thanks for watching 73
Great set of videos Peter. However I do think you missed one very important point. You did not explain where the connections for the common mode choke connect to the 9:1 balun and which of the wires on the 9:1 balun are the longwire connection and which is connected to your grounding system. Otherwise a very informative set of videos. I have a friend in Gurnsey that is having an issue with breakthrough onto one of his neighbours very cheap clock radio alarms and will certainly be recommending he builds at least a common mode choke like you have shown and the 9:1 balun as well. I have just completed the build process myself (even though I have had no reports of any problems yet) and I am just about to go to my local hardware store to get a suitable weatherproof box to put it all in. The silvered ptfe wire is more expensive but as you have shown is well worth the extra cost. Obviously I will be connecting it to my antenna analyzer before mounting it all in the box but I have high hopes for it working very well going on your results. I am sure when finished it will be replacing the commercial 9:1 balun I already have for my longwirwe as it doesn't have a common mode choke. It's really good to find designs that are shown to work along with such a detailed explanation of why you should be using them. Commercial baluns are not exactly cheap and you would hope that they would be better than they are, this just goes to show that you cannot trust many of the vendors out there. Thanks again 73's M0CNL
Im trying to find the same answer you were searching for because I want to make this 2 baluns but I want to know were the conections go. If you have the answer please Reply to this comment thanks 73
connect the commonmode choke at the 50 Ohm point. You missed it in the video at 32.05 where Peter shows the antenna connection so the other points are the 50 Ohms.
Thank You very much for your really informative Videos! Folgende Fragen habe ich: Durch die zusätzlichen Wiederstände in der Messung entsteht eine zusätzliche Dämpfung, von einigen dB, die man z. B bei der Messung mit einem Tiny VNA als Korrektur vom dort angezeigten Wert wieder abziehen muss. Ich habe diverse Werte fuer 1:1,1:2,1:4 bis 1:12 Baluns gefunden, z.B. bei DG0SA. Wie werden diese Korrekturwerte eigentlich genau berechnet? Oder als praktisches Problem: Wie berechne ich z. B. den im VNA abzuziehenden Korrekturwert bei der Messung eines 1:64 UnUn fuer ene Endfed Antenne, die in der Messung mit 3200 Ohm simuliert wird und z. B. auch noch eine 1:1 MWS davor hat, deren Mantelwellenstrom fuer die Messung durch 2x25 Ohm auf Innenleiter und Abschirmung erzeugt wird - wie im Video beschrieben? Vielen Dank fuer die wertvollen Tutorials! 73 de DO1CCC
Why did you solder the second wire to the third? Wouldn't it be much easier to simply double the length and just continue winding? Seems not logic to me...
I have notice that the coax shield wire where you soldered to the balun is long does this matter? You had said that this connection should be as short as possible. Thank you for the great video.
Peter, should I use enamel coated copper wire as shown here, or the PTFE coated ones in previous video? I need to buy one or the other so I'd like to know, thanks!
Why not the PTFE silver coated (orange & purple colors) of parts 1,2,3 ? What not the Ni-Zn core material (toroid) ? Now you say solid wire, so you imply: parts 12,3 were all stranded wire? thanks. < Great Video Series, still can't believe 1 : 1.03 SWR @ 35db rejection of common mode, WOW ! Fantastic !
Hi Peter, this is an excellent series of videos which really helped me to understand how these work. If I am to build a long wire inverted L type of aerial, would you use a 1:1 balun as you described in the series and then 9:1 UNUN? How would you make the 9:1 UNUN? Kind regards, Simon M0SYS, UK
Peter, I can't thank you enough for the 4-part video series. For my all-band, home brew open-wire feeder and 80 m loop, I needed to "tame" the impedance it presents across the HF spectrum. I "swept" the antenna, checked the data, and decided that 9:1 transformations would do what I wanted. So, last night I watched your 9:1 video and as you went along, I wound mine step-by-step. Then at the end of the video you stressed that a 1:1 current balun was required for CM attenuation (and balanced input to the 9:1) and so I watched the 1:1 build that you also provided and I built one as you described. Today and tonight, I performed a VNA sweep of the baluns to confirm performance and then placed them (interconnected) back-to-back into a CANTEX utility box (with SO-239 input & threaded-studs on the output). I tested the balun combo with my all-band antenna and on the HF bands at power levels up to 250W on all bands from 80m - 10m (fine tuning, of course, with a little help from the tuner). The baluns' performance was superb and transformed the wild impedance swings of the multi-band antenna transforming them to be within the performance specs of my matching network! I checked the "balance" on the feed line and it was ideal - far superior to the common 4:1 balun in many tuners. As a result of this two-day project, there is no more obvious signs of CMC and/or RF floating around the shack, and/or higher-than-normal noise levels. In conclusion, the balanced output of this new configuration works even better than my bare-bones Palstar BT-1500A, in my experience. THANK YOU for your contribution of time and effort. It's very much appreciated!! 73!!
Saw a comment from me that I wrote 7 yrs ago. Have had your common mode choke at the base of my hexbeam for what must be 7 yrs now. It has served me well. I have now removed it to try snap on ferrites no 31 instead of a torroid. Have now started to experience swr problems on 10m and 24megs. I am going to put the torroid one back. Anyway 7 yrs later, I am still returning to your videos for reference and an aid to my memory. I have nearly completed this 9:1 torroid, but I am putting two cores together to try to avoid heat. I am waiting for some ptfe wire to arrive for the common mode choke. I tried some cheaper silicon wire but found it was too fat to wind on the torroid. I am going to put these on a random wire antenna for the lower bands. I might use a 31 mix for the common mode because I want to get back on to top band. Up until last year, for top, 40 and 80, I just used a wire with the feeder wrapped around 4 stacked 240-43 torroids at the base of the mast, tuned at the atu in the shack. That worked well but came to grief in storms. Also I am thinking about the emf regulations so that is why am refering to your work. I will be able to put these torroids at the top of the mast, and hopefully I can avoid radiation from the feeder which now would be inside the regulation exclusion distance.
Thanks again for the tuition
Keith G0ODU
Keith, I hope you see this...
I bought some PTFE & wasn't getting the results I expected. I used a potentiometer on one leg of the 1:1 CMC and found the match was 150 ohms!! I remembering separating feedline conductors increases impedance I realized the PTFE insulation was too thick. So I ordered more PTFE, with thinner insulation. It worked!! a little tweaking of the newly wound spacing got 100 ohm per side, and a nice 50 ohm with both in parallel. An interesting journey.
Good luck with your new build!
73 de Noel ZL1NC
I am very grateful to Mr. Peter - TRX LAB - for the information that helped me solve this balun issue using the FT240-43 ferrite. I followed the guidance and managed to make my balun. I am very happy and impressed with the performance. Congratulations on the initiative and all the benevolence. 73 from this humble radio ham
I know I am just repeating what so many others are saying, but thanks you! Your balun series is the best series on the subject, anywhere. I am also one of the many really hoping you will make a 49:1 balun video. Fingers crossed. =)
Best series on baluns on youtube!
Waiting patiently for the 49:1 or 64:1 unun video. :)
For a 49:1 or 64:1 you would follow the same concept as you see done with this 9:1. The important idea is that the impedance match is equal to the square of the turns ratio. So, for a 9:1 match, the windings are 3:1. For a 49:1 match, you need a 7:1 turns ratio, and for a 64:1, you need a 8:1 turns ratio. The number of total turns on the high side of the coil doesn’t matter as long as it fits on the core, and is divisible (you can tap into it) by the ratio value that you need. So really, a 3:1 turns ratio can be a winding with 18 turns, tapped at 6 turns (1/3 of the total) and 12 turns (2/3 of the total) to get your inputs. The ends of that 18-turn coil would go to the antenna. With a 49:1 or 64:1 you would need either a larger core or smaller wire so that you could get 21 or 24 turns onto the core, tapped at 7 and 14 for the 49:1, or at 8 and 16 for the 64:1.
I find watching these videos is very relaxing and educational. They are so much better to spend time with instead of television or sports games or news. Thank you for the work you put into them for the benefit of us technicians in training around the world. I particularly enjoy watching your method and final solution.
Thanks for the kind words Ron! 73
Thank you again Peter, this is the best series on baluns any were on the internet, and I too keep going over them, a big thank you 73 from VK4JDJ
Thanks Peter, I appreciate the effort you put into these videos, being new to HF I do prefer the "proper" engineering approach you use. I am following your examples and very much like to see the testing you do, no guesswork here, as it should be, well done. Best Regards.
I'm watching this series of videos for the second time because there is
so much good stuff to learn, I need to watch it at least twice to take
it all in. You have put a lot of work into this and I'm very grateful. I
wonder how many people you have saved from radio interference and how
many rigs you have saved from too higher SWR! Thank-you.
This is my second time watching as well. I recently completed a course for electricians, where I learned a lot about transformers, so watching it the second time really solidified my understanding. It also helps to draw the device out in a traditional schematic diagram form.
I tried this on a FT140-43 core and it worked great. SWR was under 1.25 over 3 to 30 MHz and it was pretty much flat. I also wound a more typical 3 wire 9:1 unun very carefully on the same core and it was much much worse, especially at the high frequency end. I used insulated 18 AWG wire because that's what I had and it still worked great. Thanks.
Yes the best and most detailed. You are truly the best teacher, I always learn things from you I have problems learning on my own. Wish I can come be your student.
I just wound it and it worked out well - I got less than 1.3:1 from 1 - 30 MHz. I'm thinking that the key points here are the even and maximal spacing of the windings, minimizing parasitic capacitance and keeping the leads short, minimizing stray inductance. I wound it on an FT240-43 core with 18 AWG wire (all I had, but I'm never going to be using it with more than 100W).
I just wanted to thank you for the detailed instructions
This is an excellent series that I'll be referring to many times in the future!
73Thanks for the feed back
Hi Peter. I'm completing a 9:1 Balun just like your video, however, with FT-140-43 toroid. In an initial analysis on NanoVNA, the SWR from 1.8 to 54 Mhz was practically between 1.0 to 1.3. As soon as I finish the balun, I'll be posting it on my UA-cam channel. 73 and God bless you.
Your Videos are great. I have learned a lot about toroids and setting up Baluns. Have you ever thought about doing a series on 49:1 Baluns /UNUNs for EFHW antennas?
Peter thank you for this very practical tutorial on using toroidal core auto transformers. You have provided me a eureka moment (actually several) in this part 4 video. The first is the method of adding friction to hold the windings in place, second is how to evenly space the turns using indexing, third placing the primary winding in the center of the coil to produce a balanced input and output, and fourthly but not finally, insight to calculating turn spacing. I do admit to having to watch the segment beginning at 19:50 three times as at first I thought these 8 turns were being wound in an opposition sense to the first 8.
I will apply some of the techniques you present to constructing an auto transformer to match unbalanced 50 ohms to unbalanced 4000 ohms (end fed half-wave or a bisquare antenna). This will require a 9:1 turns ratio so my first attempt will be 3 turns for the 50 ohm port and 27 turns for the 4000 ohm port. I will test with an MFJ 259 analyser as that is what I have.
Thanks again for both the instruction and inspiration.
Glad that you like it Bill and thanks for your detailed feed-back! 73
Thank you very much Peter, very educational! Now I can start to make my own 1:1 and 1:9 balun!!! More power to you!
Just made mine according to your excellent instructions. My miniVNA even measured slightly better SWR so I'm very pleased with it. Thanks a lot and 73 de ON7IR
so viele wundervolle Dinge in Deutschland von der Feinmechanik bis zur wunderschönen Landschaft! Peter, vielen Dank für dein Fachwissen und deine Bereitschaft, dieses Fachwissen mit dem Rest von uns zu teilen! Haben einen gesegneten Tag!
Wow, thanks Peter, I just finished my 9:1 transformer, by watching this vid step by step. Though not as neat as your job (yet), I get very similar SWR figures on my AA-200, excellent result. Thanks you so much! (73 GW4OKT)
hi peter
great detail on baluns i have built the 9 to 1 and under test of 1 to 30 mhz the highest swr is 1.23 . best preformance of all the baluns i have built thanks again
Another great video Peter. I really like the way you explain this tutorials. Thanks for sharing. 73
Thank you Buddy this is highly appreciated my friend. Take care 73
A solder pot works great for removing the enamel coating off the wire. Added bonus it tins the wires in the process.
You are so right Mike, should order one but do not often need it.. 73
@@TRXLab I use an old brake caliper piston filled with solder and heated on a gas stove. Use it once in a blue moon but very handy.
Hi Peter, Awesome video. Very clear instructions. If followed, anyone can have a great preforming balun. I’m sure this series of videos will be referenced many times. Thanks 73
Thanks for stepping in Larry! 73
Excellent job Peter, I finally understand the concepts! You are an excellent teacher.
Thanks for feed back really glad that my videos made sense to you 73
Thank you very much, this is what I was looking for ... a very well done video with great explanation on how to build a perfect 1:9 balun !!!
Peter, thank you for an excellent video. I am a subscriber and routinely use the information you provide to assist me with my projects. I just completed winding this balun. My testing showed a VSWR of 1.0x all the way up to 30 Mhz where the VSWR was 1.3. I used a ft-240 mix 61 core. The tips you provided with the dots and the cloth tape were very helpful.
glad that you liked the video! Thanks
Excellent tutorials. Best I've seen. Plan on watching them all
Super fantastic tutorial video. I been waiting on this one. Quite a value for a top notch balun. Great work and much thanks. A big thumbs up !
Thanks you, glad that you like it 73
I made this Balun and it worked perfectly. Thanks for showing me how!!!
Glad that all is working fine and thanks for feed-back Nicholas Cheers
German precision at it's best! Great video! Thank you
Thanks Bobby!
Nice illustration of how to build a transformer. It would have been even better to see a traditional circuit diagram of the device. As far as I can tell, this is an auto transformer with input taps at 1/3 and 2/3 of the total winding, with outputs spanning the entire winding. So if I’m not mistaken, here we have two, 3T:1T auto transformers in this one device. And 3:1 turns ratio results in an impedance transformation which is the square of the turns. This really would be easier to visualize with a traditional schematic component drawing.
Thank you in advance Peter, this was fantastic to watch.
This is brilliant , totally sorted my tx problem out, also on rx, it seems a lot quieter . thank you so much.
Thank you for your efforts doing this series, it has been am inspiration for me to build things again. There is no doubt these work :)
Always Enjoy yr channel Peter,. Thankyou for propagating this knowledge, have watched the entire series, 73
Thank you!
Hi Peter.
Another great video series. you keep putting out some of the best vids out there.
I will tell you one of my secrets for 9:1 Baluns.
I use a t150-52 iron core with 10 or so turns. and is flat across all the hf bands
You will find these in many switch mode power supply's. Green/blue toroid. and at 1/4 price. I haven't used these above 125 watts but they work for me. I also use some of my beldon 83336E stash I have.
Keep up the great work!
Thanks for feed back and for your hint! All the best 73
Hello Peter, thank you for your very interesting videos. I particularly appreciated the BALUN series. I'd like to add my request for a 49:1 and 64:1 transformer's for end fed antennas tutorial.
Thanks for feed back. I'm sorry have not the resources to deliver on your request. 73
Thank you anyway.
I put together a 1:9 unun as per instructions here. When I tested it with a 448 ohm resistor chain, the VSWR was 1:1 to 1:2 from 1 to 30 MHz. Suffice to say, I am very happy. However, besides testing it, he doesn’t go into how it is supposed to be hooked up to an antenna system.
I am trying to get the same answer. did anyone figure out the 1:9 unun output which is hot and ground. Thanks in advance for any help.
Wow, this is the best series on baluns and common mode attenuation i have ever seen. I have already built the 1:1 and the 4:1.(Wunderbar) The 9:1 is next, I would really like you to do a build of Wolfgang's the 6:1. Vielen Dank Peter fur diese Serie. Barnie M7PBX.
I'm sure that your RF transformer (mix 43 toroid?) has good performance, but SWR is not the right way to dimostrate it: you checked how much RF power is reflected back, but you don't know how much is provided at the secondary terminals. Also a dummy load shows a very good SWR but the whole power is converted into heat!
So, measure the SWR with the secondary open and then with the secondary shorted: if your transformer has low losses, as I think, almost all the RF energy will be reflected back in both the tests (very very high SWR).
For an insertion losses precise measurement connect also the secondary: connect it to the second port of the VNA with a 400 ohm resistor in series: measure the loss between one port and the other and divide it by nine (it is not necessary to explain why...).
Even better if you make a second identical transformer: for this test connect the 450 ohm secondary of one to the secondary of the other, and the primaries to the two ports of the VNA. Measure the losses between the two ports and divide it by two.
Let us know. 73s
Excellent info. Now how do I get the wire antenna over the trees in my garden?
Thank you for the very slow and complete explanation! ... Too bad you don't enable the subtitles!! My English is basic, and I can understand it by watching it 2 or 3 times... ! Well that's how I practice English!! Most baluns fail because of something as simple as the correct spacing of the turns! -Very well explained!! ..73 and DX's Enric, EA3FSU.😅
I built this from your video and it works PERFECTLY. Thank you for such good direction! 73 de WW1L
Peter once again another outstanding video, you seem to have the gift of being able to tie theory together with practical application. There was only one point that may need some clarification for the young players out there and that was the turns ratio vs impedance ratio. What you built was a 9:27 (or 1:3) autotransformer with the impedance transformation being the square of the turns ratio, hence the 1:9... Thanks again for sharing I look forward to your next video. 73
Hi Michael, the equation ans explanation has been shown in part 3. Thanks for watching 73
Nicely done. Easy to follow instruction. Thanks for posting this great video.
Barry, KU3X
HELLO FROM GREECE..THANK YOU FOR THE DETAILED VIDEOS...PLEASE TELL ME HOW YOU DETERMINE THE POSITIVE AND NEGATIVE POINT FOR THE 50 OHM AND THE POSITIVE AND NEGATIVE POINT FOR THE 450 OHM ...REGARDS...
Excellent videos. Built a 1:1 current balun (with proper core materials) and works beautifully though only up to about 30MHz. No problem since I'm building a 20m dipole. Suggestion for a part 5 video: 49:1 transformer for half-wave end fed antenna. It would be interesting to compare your approach to the one i built. -73 VA3GLB
Excellent! Very well explained, thank you.
Great job on this series Peter :) Thanks
Glad that you like it Grant. Thank you 73
Vielen Dank, Ich bin neu bei Amatuerfunk HF. Meine Familie stammt ursprunglich aus Wien und ich lernr wirklich Deuctch. Ich Leben in den Vereinigten Staaten.
Nochmals vielen Dank fur das Video.
Peter great content. The whole time thing you was making a 49-1 guess I need to see the rest of the Series
This is an interesting design for 9:1. You're feeding the auto-transformer across the middle of the three windings, where most 9:1 UNUN feed across the 1st of the three. I wonder what the result is in a typical application using an end fed "random" wire where you ground the other 1/2 of the output? With the traditional design one connection is already at ground anyway because the coax shield is there. Not sure how it ends up with ground connected to two different places in this setup. I'll have to try it out - and great stuff as always Peter.
Very nice explanation, about BALUN..
Thank you Ari 73
Thanks for the video tutorial, Peter !
You are welcome! Thanks for watching 73
As always, great video. Enjoy your attention to accurate detailed workmanship. Does the type of insulation for example, THHN electrical wire insulation on 14awg solid matter in winding a balun lets say a 1:49, or some refer to as a 49:1 unun? Will it create resistance and change not only impedance in the balun, but wire length of 1/2 wave efhw. How would electrical wire using THHN insulation effect making a 49:1 unun and what would be the suggested distance between the outside of the windings of a 49:1 unun IF that type of wire is used?
Hi Peter
How do you calculate the number of turns required for the 9:1 UNUN?
Thanks for all your interesting videos
miss your repairs. I hope everything is ok. Maybe you will start up again.
Greetings... excellent series. Is there any chance that you can activate the subtitles for videos 3 and 4? thanks!
Excellent video
Does the cloth tape also provide insulation - preventing the wire from shorting out through the toroid ? The enamel insulation on the wire seems unlikely to oppose the voltages involved ? Thanks for an excellent video.
@trxlab . Im building your 9/1 unun. I'l looking forward to launching a long wire over the Oak trees in my backyard. So, I would like to have 160m through 10m if possible and with all the talk about random wire antenna lengths, I believe I have room for 500+ feet wire lengths. do you have any ideas on wire lengths, is longer better and should I use ptfe or solid core and what gauge? Do you have a series on long wire antenna lengths? thank you for your time and I very much enjoy your series.
Great video Peter please provide a schematic of the 9:1.
73
Hi Alan, finally it is a simple autotransformer like the 4:1 in part 3. Hope that helps 73
Thank you very much for sharing this.
Again thank you for a great tutorial. May I ask please how then do we cut the long wire to resonance because the transformer wont let u see the antenna properties.
Instead of making the first solder joint you can just make the wire longer in the first place and wrap the second winding without having to solder more wire on.
Peter, excellent video series! I have referred my ham friends to you who I've inspired to DIY ununs/baluns. Question: you recommended PTFE wire for your 4:1 and 1:1 projects, yet in this 9:1 project you are using enameled (lacquered) wire, why is that? PTFE provides both superior heat and electrical resistance compared to enamel insulation, and in the case of an end fed random wire antenna that uses 9:1 transformer the voltage will be at its highest at the feed point, which can reach a high level (ditto for end fed half wave antenna that uses 49:1 transformer). The 4:1 and 1:1 balun project videos (I watched all those) you use PTFE wire in transformers that are typically used with center-fed dipoles or loops where feedpoint voltage is at its lowest (and current highest). It seems quite opposite recommended wire to me. With that said, I have typically used enameled wire for end-fed antenna transformers in QRP applications, which of course would be relatively low expected voltages, but here in this 9:1 you are talking about 800W and above? What say ye?
Excellent video Peter.
Glad that you like it Howard...73
Die gleiche Kombi habe ich bei Wolfgang bestellt ( Bausatz , Mantelwellensperre und 9:1 ) funktioniert einwandfrei .
Gut gemachtes Video , wie immer sehr ausfürlich . thumbs up ;-)
Ja da hat Wolfgang wirklich gute Arbeit geleistet. Danke für's vorbeischauen 73
I loved the Balun video series Peter, how about a 1:64 EFHW HF antenna Balun?
Thank you John. 73
@@TRXLab yes please! 1:49 and 1:64!!
Dear Peter thanks for all valuable information given to this video series. Is it possible to attempt a 1:49 Balun for high power as well? Thank you in advance and please keep doing the really good work
Where do I connect so239 and what about antenna radiator wire and caunterpoise. Great video thanks for the explanation
Excellent presentation. I think it should be emphasized a bit more that the load resistors must be non-inductive. That may have been part of the issue with the SWR rising at higher frequencies. Thanks.
Yes with hight frequencies the dummy resistor becomes more and more important. Thanks for comment 73
Would this be a good dummy load for 450 ohm?
www.amazon.com/uxcell-Green-Aluminum-Housed-Resistor/dp/B008FZBLK0/ref=pd_lutyp_im_4_1?_encoding=UTF8&pd_rd_i=B008FZBLK0&pd_rd_r=121ZHFZMG06004CQ3MSB&pd_rd_w=jedWF&pd_rd_wg=xm5Xe&psc=1&refRID=121ZHFZMG06004CQ3MSB
Dale Ferrier
Wire wound is inductive --NO
Very neat turns! Excellent balun video set, many thanks!! 73 de G2DS.
Thank you
this is an amazing series!!!!!!!!!!!
wow - so so clear, and so precise!
thank you!
coudl i ask for a part 5 please ?
1:49 transformer???
a little sand paper action works well to remove the di electric insulation off of the transformer wire ... also why not use pvc coated / jacketed wire ? ?
Thanks for the video. Can you explain why you used three wires? Why can you not make 24 turns with one wire and simply tap the coax inner by soldering to turn 8? Isn't the magnetic field generated by the signal uniform throughout the ferrite core? Also why is this a 9:1 transformer if there are 3 x 8 turns. Why is it not 8:1?
Matt Haxx Hi - with this winding method we get 8 turns primary and 24 turns secondary, so a 3:1 turns ratio. The impedance is proportional to turns ratio squared, so 9:1 :) .
If possible, can you please provide informaiton on makiing 2:1 balun? Probably just the number of windings.
amazing work! thanks Peter
Thanks a lot for doing this informative video. But, I do have a question. Would someone please comment and diagram the 50 ohm and 450 ohm connections as they relate to signal and ground. I just want to make sure that I have the input and output connects made correctly. Thanks.
Danke dir fuels video. Habe gerade ein 9.1 gewickelt aber jetzt bleibt mir die frage welche der Anschlüsse ist der Strahler und welches der Counterpoise/ground ist.
Hilfe bitte.😊
Peter, this is a Fantastic series indeed. Been a long time fan of your channel. I'd like to ask if the space between the two completed Baluns is crucial to be about ~3.5 cm as it is in your video, or could it be 0.5 cm ? I have a box that could house these two baluns at this smaller distance just fine, but I am worried if it will undermine it's performance. Thank you for your helpful reply in advance.
Excellent video...thank you. Peter, I have one question, how to hook up the two wires to a single longwire antenna? The HyEnd wire antenna has only the wire attachment to the balun box and no counterpoise, can this be duplicated with this transformer design?
Fantastic video Peter
Thank you John
Hi again,
Could you truly complete this series by showing us how to make a 2:1 balun for use with a quad loop wire antenna. Thanks.
Yeah Peter it is all a matter of time....Thanks for watching 73
TRX Bench I would be interested in building the 2:1 balun for the same reason. After watching the 4:1 balun video I think I figured it out but without proper test equipment I don't want to cooka radio to find out 😂. Thankyou for your video series
1:25 is more interesting because i wanna make a monoband deltaloop.
Tnx a lot for all the infos
I'm looking to build an 18:1 Balun for a rhombic antenna. But can't find any info on google. How many turns is kind of confusing to me. Thank for all your teaching TRX Bench. Will be attentive to see if you show how to make a 18:1 balun. Cheers.
It seems like one of the main points is that you space the tri-filar windings as much as possible. Is this to keep the inter-winding capacitance to a minimum?
one more question on building 1:9. what happens when adding more turns?
Thank you for this series - it is beyond excellent.
Is there any detriment to using solid 14awg (~1.62mm) transistor wire for the 1:1 attenuator or the 4:1 transformer? I will be building 3x 1:1 attenuator, 1x 4:1 transformer, and 1x 9:1 transformer. If there is no negative effect, I would prefer to use the same wire for each component and am too inexperienced to identify a negative from using 14awg solid for the previous builds.
Peter - thank you for the excellent videos on making baluns. I would not have attempted this without your patient explanations and demonstrations. Two questions: 1) Is the PTFE wire for the 1:1 and 4:1 baluns solid or stranded? Does this make a difference? 2) How critical are the lengths of the wires that connect to the SO239 connectors? If the "hot" lead is shorter than the "screen" lead will that make a difference in the SWR?
Mark, W9MS
Thank you Mark, the wire is PTFE and stranded. Under heavy load the balun cpild get hot so PTFE is a good idea. The wires should be as short as possible but it is not to critical if screen is a bit longer... Thanks for watching 73
i made one with the same 18 AWG wire i made my 4:1 balun the SWR is a bit high at 1.7:1 at 30Mhz so i may rerap it with 1.5MM copper wire.
Did the swr go down when 1.5mm you used ?
Great set of videos Peter.
However I do think you missed one very important point.
You did not explain where the connections for the common mode choke connect to the 9:1 balun and which of the wires on the 9:1 balun are the longwire connection and which is connected to your grounding system.
Otherwise a very informative set of videos.
I have a friend in Gurnsey that is having an issue with breakthrough onto one of his neighbours very cheap clock radio alarms and will certainly be recommending he builds at least a common mode choke like you have shown and the 9:1 balun as well.
I have just completed the build process myself (even though I have had no reports of any problems yet) and I am just about to go to my local hardware store to get a suitable weatherproof box to put it all in.
The silvered ptfe wire is more expensive but as you have shown is well worth the extra cost.
Obviously I will be connecting it to my antenna analyzer before mounting it all in the box but I have high hopes for it working very well going on your results. I am sure when finished it will be replacing the commercial 9:1 balun I already have for my longwirwe as it doesn't have a common mode choke.
It's really good to find designs that are shown to work along with such a detailed explanation of why you should be using them.
Commercial baluns are not exactly cheap and you would hope that they would be better than they are, this just goes to show that you cannot trust many of the vendors out there.
Thanks again
73's
M0CNL
Thanks for feed-back 73
Im trying to find the same answer you were searching for because I want to make this 2 baluns but I want to know were the conections go. If you have the answer please Reply to this comment thanks 73
connect the commonmode choke at the 50 Ohm point. You missed it in the video at 32.05 where Peter shows the antenna connection so the other points are the 50 Ohms.
Thanks for the video tutorial, Peter !! Will your design work with an inverted v dual band fan dipole?
Yes of couse it will work with any antenna type may be together with a tune...Thanks for watching 73
Thank You very much for your really informative Videos!
Folgende Fragen habe ich: Durch die zusätzlichen Wiederstände in der Messung entsteht eine zusätzliche Dämpfung, von einigen dB, die man z. B bei der Messung mit einem Tiny VNA als Korrektur vom dort angezeigten Wert wieder abziehen muss.
Ich habe diverse Werte fuer 1:1,1:2,1:4 bis 1:12 Baluns gefunden, z.B. bei DG0SA.
Wie werden diese Korrekturwerte eigentlich genau berechnet?
Oder als praktisches Problem: Wie berechne ich z. B. den im VNA abzuziehenden Korrekturwert bei der Messung eines 1:64 UnUn fuer ene Endfed Antenne, die in der Messung mit 3200 Ohm simuliert wird und z. B. auch noch eine 1:1 MWS davor hat, deren Mantelwellenstrom fuer die Messung durch 2x25 Ohm auf Innenleiter und Abschirmung erzeugt wird - wie im Video beschrieben?
Vielen Dank fuer die wertvollen Tutorials!
73 de DO1CCC
Why did you solder the second wire to the third?
Wouldn't it be much easier to simply double the length and just continue winding?
Seems not logic to me...
I have notice that the coax shield wire where you soldered to the balun is long does this matter? You had said that this connection should be as short as possible. Thank you for the great video.
It will matter a bit but for this test configuration it is fine but for the final product it would be unacceptable. Thanks for watching 73
Peter, should I use enamel coated copper wire as shown here, or the PTFE coated ones in previous video? I need to buy one or the other so I'd like to know, thanks!
what size is the transformer wire used in this 9:1 video? 18 awg? and great video's on this you helped out a lot thanks.
Hi Wally, yeah 18 AWG will work fine. Thanks for watching 73
well thank you for your reply great job keep it up.
May i suggest a video in how to make a 2:1 balun.
Why not the PTFE silver coated (orange & purple colors) of parts 1,2,3 ? What not the Ni-Zn core material (toroid) ? Now you say solid wire, so you imply: parts 12,3 were all stranded wire? thanks. < Great Video Series, still can't believe 1 : 1.03 SWR @ 35db rejection of common mode, WOW ! Fantastic !
I enjoy the series however do not have data on the core you use . Or where to obtain them
www.amidoncorp.com/ft-240-k/
Hi Andrew, thanks for watching. You question has been answered by Jason already. Thanks to Jason 73
Only you specified that you used material 43 and not K. According to Amidon these are very different materials.
look at his part 1 he talks about it...
Hi Peter, this is an excellent series of videos which really helped me to understand how these work. If I am to build a long wire inverted L type of aerial, would you use a 1:1 balun as you described in the series and then 9:1 UNUN? How would you make the 9:1 UNUN?
Kind regards,
Simon
M0SYS, UK
Hi Simon, thanks for feed back. If you put the 1:1 first and add this 9:1 behind it your set up should work fine...Hope that helps. 73
TRX Bench hi Peter
Thanks for the reply, is an UNUN the same as the BALUN but with the connections reversed?
Hi Peter
Is an UNUN the same as the BALUN but with the connections reversed?