Easily Test An UnUn Before Deployment (9:1)
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- เผยแพร่เมื่อ 2 ต.ค. 2024
- This is a brief demonstration on how I test a 9:1 before my deployment.
I am testing to confirm the 9:1 is wrapped correctly and there are no issues with the wrap itself (or solder points).
Please let me know if you have questions and if you have a better way, let us know in the comments below!
Lengths for a 9:1 (As I mentioned in the video)
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Thank you for making in simple. Iam a hands on person and this really helps
Thanks for the video, I have a balun that needs testing, and I just needed confirmation that my wacky theory of a test rig was right.
Good stuff! Gunna test my Ape-inspired 49:1 EFHW unun with this technique. Thanks for sharing!!
Excellent! Best of luck! Ape has a more technical video on this same subject, he released it about a month ago (didn't know before I posted). If you're interested, he goes in a bit more theory
Also, I hope you're well
Thanks for this, is a simple but effective test before deployment and very well explained.
Great explanation, very helpful. I could not get my 49:1 to work correctly. I will try the resistors tomorrow and test it
Thanks so much for this really helpful tip. Brilliant.
Thank You, Paddy. It's proven to be a good method for me and seems to work okay to get in the ballpark. Have a good one!
Good video, great explanation. Truly it was so dang simple and obvious. I am mortified I never even thought of that at all. Thanks Dude!
Thanks much!
Thanks for the video dude! Very helpful this noobie!
Please make a Video on How to test a frequency trap , good to be used with 49 :1 multi band LEF wire antennas
This was a really cool video, thanks Dude!
Glad it could help
Getting a different impedance at higher frequency is not just a matter of the connector. The inductor itself behaves different at different frequencies, a function of core type, wire size, winding proximity, etc. A 9:1 transformer is not evenly 9:1 across all frequencies; whoever built it decided on a toroid and type, hopefully with an eye towards what frequencies it'll be used for.
Don't know how easy that pen will be to clean off after a few uses but it definitely gives an "ooooh, that looks nice" feel 😊
Oh, and not forgetting ... the content was good too! Useful 👍
I think I'm getting new mat soon. This is currently a mat for arts and crafts 😂
Just had to do this with a bought 49:1 (cheap import) which just wasn't matching. Examination showed one wind too many on the primary! Took out a turn so it was 2 turns to 14 (rather than 3 to 14) and of course everything was fine. I used some resistors in series I had on hand to make the test load as near 2400 ohm as possible and my microVNA. - sorted.
Excellent
Unun is unbalanced to unbalanced. Balun in balanced to unbalanced. 450 ohm line is balanced and 50 ohm coax is unbalanced. You have tested a balun not an unun.
Thanks. Do you have any documentation that is easy to follow? I ask, because I am referencing websites and then I think I understand it; Then I find out, that about 90 percent of the websites out there are calling a 9:1 an unun... So if I had some documentation and examples of Balun vs Unun, I think I could make a video after understanding it better and hopefully help clear the confusion. Thanks for any resources you may have
@@HAMRADIODUDE Good job. The unit you made can be used as a balun with balanced 450 ohm balanced twin lead to feed a G5RV for instance. It also can be used as an unun with an End Fed Half Wave by attaching the antenna wire to one side and a counterpoise earth to the other side. Your videos have good lighting, good audio and contain good details so well done. Google is your best friend preparing these videos. So are other TH-cam videos. Plenty there to research. Keep up the good work.
It's called,
" In Series " !
Resistors in series : ADD
Resistors in parallel :
Subtract
👍😉
Thank You !
Thanks for the information it was very helpful.
You're killin me with the paint pen, dude! .. HA ... my youngest loved using a paint pen... was always nervous she'd draw somewhere she shouldn't
Love the video... Keep doing what you do!! 73
Reminds me of the time I used a dry-erase marker to label hundreds of vials for a sterilization experiment prior to putting them in the autoclave.
I think the visual representation worked well... But yes, there's marker all over my clothes 😂
Does it matter what side you’re counterpoise and radiating element connect to and if so, how would you tell if you have one that is sealed up with no labels?
Generally the counterpoise should be closer to the SO239
Fine business I ordered parts today for a 49:1 everything but the enameled wire ? Can i get by with insulted 14 gauge from say Romex KE4TDG. 73
Nice test, but I’m not going to go out and buy a $300 antenna analyzer to do this test
I understand. You can buy a 30 dollar one (Nano vna or whatever). Cheers.
Very well explained and illustrated.
Thank you.
Thank you!
Great video.
Just a thought.....
get a 2 or 4 position rotary switch
get a couple of female banana plugs
get a couple of leads with a banana plug on one end, and an alligator click on the other
get a small enclosure
solder the switch input to one of the female banana plugs
solder the resistors from each pole of the switch to the other female banana plug
mount the switch to the top of the enclosure
mount the female plugs one to each side
close the enclosure
label everything
now you have a test box to switch from one set of resistor values to check your ununs
That's awesome!
Did you use ordinary or low inductance resistors? Those can be hard to find, but the ordinary wire wound ones can give some bad impedance readings.
*Several minutes of video, and you never show the plan of what you did????INEPT!*
In the video I show 450ohms crossed between the antenna element and the counterpoise. I did not show a schematic but rather explained it. I can draw it out if you would like
@@HAMRADIODUDE *In a tutorial on a balun, the logical and default thing would be to show the connection of the balun that you are still showing,*
*((basic behavior))*
Good afternoon.
I want to measure a 49:1 unun, it comes to be 2450 Ohms. Should I build a 2450 Ohm resistor for the test bridge or is the 470 Ohm resistor enough?
Thank you
Julio
OA4DXW
73
Very helpful
Thanks! Quick question: can you use an unun instead of a balun on a folded dipole antenna?
HRD I'm wondering how long before some person acknowledgers my post? You asked if any person has new material and trying find out more.
Is that an unun or an unbal? 1st thing that popped into my head when i saw it was to transform to 450 ohm was ladder line converter.
Has anyone tried a 49:1 ( tapped at 2 turns the normal way) and tapped off also at 6 turns to make a 9:1 on the same toroid? vk2jcc
When I was a kid, my dad made contacts in many parts of the world either by voice or cw. The general impression I am getting from watching ham radio videos is that this type of activity is all but dead. Am I just not watching the right videos ?
*JAMAS MOSTRASTE EL PLANO DE CONEXIONES DE TU BALUN!!!!*
*INEPTO!!!!*
I'M SORRY, I CAN'T READ CAPS LOCK.
@@HAMRADIODUDE
*You can't read capital letters, BUT YOU CAN WRITE THEM?????*
It would be about a 2.4k resistor for testing the 49:1 it seems.
Tnxs, how to find some ohms
Thanks for watching, Paul
Ham Radio Dude- just found your video, all good except i dont have an analyzer, what can use to substitute
You could just hook it up to a radio and check the SWR. It's going to be painful and if you're not resonate within the bands you can transmit on, it's going to be very difficult to tune/confirm functionality, but it could be done.
Explained nicely
Thank you!
This Old Tony?
This Young Dude?
Excellent Dude ! No Bogus Baluns....lol
Doesn’t work this way with a 49:1. The secondary on a 49:1 is part of the resonant circuit formed with the end fed half wave length of wire. I tried this with 4 different 49:1 ununs and was getting a weird dip at 2.5 mhz and high swr in the rest of the band but when I connected my half wave wire, all the dips were right where they’re supposed to be.
You're right. I confirmed the 49:1 with the same results. Sorry for the misinformation
@@HAMRADIODUDE Thanks for checking and replying! It seems a lot of folks are misunderstanding the 49:1. I’m glad to hear I’m not crazy.
I'd be inclined to say that since you see the dip, that's a good indication. If there's no dip for anything that doesn't come relatively close, that's where you start to see an issue with your wrapping or something along those lines. I think the best experiment would probably be to wrap it once, check wrap it twice check and see and watch what it does on the spectrum
@@HAMRADIODUDE Just out of curiosity, what kind of curve did you see in your analyzer with the dummy load? I always get a dip around 2 to 5 Mhz and then the SWR is off the graph by around 14 Mhz. I've tried 3 different type 43 core configurations and always get a similar result.
Thanks dude!
Tha is for this info!
Thanks for the Video Ham Radio dude
Fantastic vid. Thanks.
I would solder, heat shrink and add alligator clips to your resistors for quick connect 👍
Great idea. I will! Thanks!
So how do you test for loss ie loss of power output and rates of power ie QRP vs QRO?
This is a great question. It may be an answer for the smoking ape. Let me ping him
I would think the best way would be to perform an insertion loss test on a VNA doing a S21 LOGMAG, that said I am not sure I found a way to do this where I am confident in the results. Power level shouldn't matter in this type of measurement provided that the antenna is designed to handle QRO.
how many feet of wire is a 9:1 unun happy with?
Hello. There's a good chart in the description of my video. I have used 37 and 44 ft with okay results. I was constricted with space. Best of luck
If everyone would quit using the powdered iron cores that are designed for use as inductors in tuned circuits such as antenna tuners and low pass filters in amplifiers and transmitters and use ferrite cores like a mix 43 or mix 61 that are made to be used in baluns and ununs, the test results would be a lot better!
Thanks.> If you would like to contact Princeton Antennas, that's who made this Random Wire 9:1. 73
@@HAMRADIODUDE Learn to build your own ! FYI, a 9:1 UnUn is designed to feed a 450 ohm load and a random wire is only going to be 450 ohms on one frequency!
I'm here first!
Excellent yet simple description. Thank you for posting this video!
Glad it was helpful!
49- 1 60 of wire would work 10-40 yes
Hi Paul. a 49:1 with a T140-43 torroid can be used within the 80-10 range, yes. If you have a 49:1 with an antenna length cut for 1/2 wavelength (65.6 feet, depending on the wire you use (Velocity factory could play an effect and technically make the antenna a little shorter)) of 40m, you will get: 40m, 20m, 15m, and 10m, all should be without the use of a tuner. I have not attempted, but with 1/2 wavelength worth of antenna wire for 80m, you should be able to get 80, 40, 30, 20, 15, 12, and 10 under 2:1 SWR, with 17m possibly being slightly above 2:1. Thanks!
@@HAMRADIODUDE tnxs Dude. It's hard to said where you are. Must be on Permanent vacation. Lol
How everything is ok on your end, can't say that. My mind is like racing engine and the brakes are not working. Free wheelin. Trying to put together a go bag. G 90
Looking at the POTA There's a whole bunch down here in Florida, And I won't have fun.
@@HAMRADIODUDE how do you know what torrid to use and how do you measure the impedance of your wire. Yes I should know that.
HRD just a thought with the resistors in line, and a AM carrier of 5 watts, and a piece RG 58 as a coax capacitor, connected earth & wire connected to Aerial inside the box.
Now CUT your RG58 , cut off small pieces of cable and have look at your VSWR in line ....the SWR going down and slowly I get a 1: 1 in the cable. Leave RG58 in box as you have soldered it. Give it a go mate Dennis vk4oc.
Thanks. Very interesting
I'm going to have to give it a shot. Sorry for the delay. I see all the messages but I'm having a difficult time keeping up at the moment .. I'd like to try this to see the happens, I appreciate it!