ฝัง
- เผยแพร่เมื่อ 27 ก.พ. 2019
- This is my new design of the small 9:1 UnUn for portable QRP Random Wire Antenna. In this video I show you this small home made QRP UnUn and I do quick impedance test.
In the second part I want to test this antenna in the real portable conditions...
I will very appreciate if you will support my work and you became to my patron on Patreon ;-) / om0et
Thank you very much for watching my videos! 73 Paul OM0ET
#9:1unun #endfed #randomwireantenna - วิทยาศาสตร์และเทคโนโลยี
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You are never short of ideas for new projects Hi
I'm impressed, great job Paul.
Heh :-) thank you! It's my passion - this beautiful hobby... :-D 73 Paul
Very neat looking. Well done!
Brilliant design.
I look forward to your next video testing the qrp mini 9:1 unun with a random wire. Thanks KG7CQG
Very neat. Another one to add to my list of Things To Make.
cant wait for the test.
Very nice unun!
Nice job. It will be interesting to see how well it performs.
very nice work...like 4 qrp...we are still out there amongst the killowatts from the East!!!
Very Efficient 9:1 UnUn - Almost all of your power is being transmitted ! All Amateur should have one of these, especially for QRP. The packaging is perfect. You should manufacture this.
Hello Paul. This is great.
Thank you John! :-) I am curious how will this antenna work.. :-) 73 Paul
Nice job as usual. Bravo Paul
Thank you very much my friend 😉👍 73 Paul
VERY INFORMATIVE TO NEWBEES
I like that PVC coupling a lot better than the box I don't know why I just like it
Yes me too. It's more practical and better to carry in the small bag 😊
@@OM0ET yes I'm glad you understand lightweight great for bringing out in the field really good deal thanks for sharing again my friend goodbye from Atlanta Georgia
Excellent video, best of luck on your field testing.
73
WD4DDA
Thank you. :-) I believe in this antenna. :-) 73 Paul
Excellent project. Just curious, you said this has five three wire windings, but other videos shows 8 windings............
Hello paul i wait with great interest the following in real test Best 73 of ON4LBF Albert
Hi Albert, thanks to watching! I am waiting for good WX and hope for more time to go out somwhere with my radio love :-D and do some QRP contacts... stay tuned :-) 73 Paul
Very interesting design! You keep coming up with clever ideas. I am curious, where does the ground (- wire) lead go to? I thought an UnUn had a positive and a negative lead. Anyway, great stuff, as usual, Paul. I wish I had your skills. Very 73 from MN! de WX0V
Thanks! It will sounds strange but during the tests in the past this antenna worked better without negative lead or ground. So I decided that in this version I will not use GND :-) I will see how it will work :-)
Very interesting. Anyway, your Mini-Un looks great...like it was store-bought...really cool...well done, sir! 73! de WX0V
@@SuburbanDXing Thank you very much Scott! ;-) 73 Paul
Nice. Finally somebody who actually had portability in mind. I'm not sure if I would trust the end caps though without actually gluing them in. Would be a shame if a gust of wind would rip the whole assembly apart. Still wondering how Chameleon managed to squeeze a 5:1 into a tube that's not a whole lot thicker than yours (Hybrid Micro).
Thank you! Hmm I had never seen that Chameleon product before so it's hard to tell :-) There is almost no pull force on the caps or UnUn body itself because the main pull from tree to the ground hook is in line and antenna wire with rope meets in the point of the UnUn antenna screw. Let's see how I explained it here: th-cam.com/video/z9fJLo63ne0/w-d-xo.html but of course there is no problem to glue it inside too or cross the tiny screw trough tubing in to cap :-) 73 Paul
@@OM0ET hehe your project just happened to be Inspiration enough to get into searching once more. Turns out that the UnUn design of the Chameleon is a copy of what was in the Comet CHA-250. That in turn led to somebody who had copied that and stuck it into a tiny film roll can. So yeah, mysterious ways, but I think I positively identified the Chameleon ferrite core as an Amidon BN-61-002 or the type 43 equivalent - which should both relatively easily fit 1/4 inch copper pipe. See here th-cam.com/video/4n30XykCChY/w-d-xo.html and here sp7q.blogspot.com/2012/03/kopia-anteny-cha-250b-va250ha.html
I like the Chameleon idea of using the balun both for a wire and as a base for whips - just don't like it $200+ dollars much for a balun and a wire, not including the whip antenna. The ferrite costs like €6.50 at most. Add a PL or BNC connector and some other hardware and it's somewhere around 10-15 at the very most. With the right threads it will accept cheap military surplus whips.
So yeah, your video was a great reminder that we don't need 200+ Watts baluns to feed them with 5-10 Watt QRP rigs. Much needed.
@@KannixKostnix I don't know what cost is the CNC manufactured body of this product. I suppose that construction of the Chameleon UnUn costs a lot because look very proffesional made. I do my antenna as small as possible but they still should work good for QRP because every gram or centimeter counts when I work portable and I have to carry all this staff :-D I don't need equipment for 50 or 100W because I will never use that power with my QRP equipment :-) And my opinion is that I have more fun when I make QSO on 5W with somebody instead of 100W or more :-) 73 Paul
@@OM0ETYeah it wasn't meant as a rant against Chameleon, because it's a commercial product after all, and how well it is made as that can clearly be seen in comparison to that Alpha piece. I'd still recommend it to anyone who can't or doesn't want to do some tinkering himself. But you don't need CNC if it's not commercial mass production. A drill press and some files at most. Or do the PVC pipe thing like you did. Too bad that unless winter is coming back, the tinkering season is essentially over. ;)
@@KannixKostnix :-) I suppose you live in the southern Earhts hemisphere when you say that winter is coming :-) We in Europe are happy that finally spring is coming and I can do QRP portables finally hihi ... finally warmer times! You have to move to Europe for couple of months now ;-) 73 Paul
If 9:1 how does it work with what looks like 4 trifiliar turns? Can transformer rating ferrite cores do any good on just 20m and 40m? I have a bunch, from 1 1/8" o.d. to .5" o.d. and nobody peeps a word on their use, except 1 person says they lose their inductive multiplying properties at higher frequencies. No longer enjoy tinkering with a cap loop, just to recieve, and phase 2 for low swr, just want an antenna to trust, no tuner, on 2 or 3 bands for QRP use.
I’ve used a red one
Man you work so neat and clean. I think you can make it for sale. 73
Thank you Ed. Will see how this UnUn will work and if will so I can make couple to sell... hi :-) I am still waiting for better WX here in my QTH to make an another video with portable test. 73 and have a nice day. Paul
@@OM0ET I'd buy one
@@The-ir1vj no problem 😉👍
I saw the testing in real enviornment. But did not work well. But curious to know the unun which you made in a transparent box also gave you 1:1 at your qth with 450 ohms ?
I think that this small yellow toroid is wrong material for it. FT50-43 would be better with better results.
Toroid amidon?
Excellent Paul!
Must ask: What you are using to make your labels?
Hey Adam, I use transparent A4 format label for laser printers and I create it in OpenOffice Draw software. 73 :-) Paul
Thanks Paul!
Looks like I need to get a laser printer!
73's!
@@AdamSWL 😀 yes exactly! Good luck 73 Paul
Hi, you've made an awesome job! I'd like to ask if there is any possibility to get any schemes of this variable resistor mentioned in the video?
73
Thank you. Do you mean this tool?
@@OM0ET I mean the variable resistor you've made. How exacly you made it/where you bought it?
@@xnoskillek I have found this translate.google.sk/translate?hl=sk&tab=wT&sl=sk&tl=en&u=https%3A%2F%2Fwww.gme.sk%2Fpotenciometr-viceotackovy-pm-2010-1k
@@xnoskillek if you send me email I will send you diagram, OK?
sq3shi@wp.pl here's my email, huge thanks :)
Hi. Which toroid you used when this 1:9 UNUN is made? It's looks like T68-6? This is right. Thanks for your answers. 73 de TA9AAP.
I am sorry, but I don't know to answer because I just bought it on HAM meeting without any type or name this toroids.
@@OM0ET Usually, I use Ferrite toroid. Because Ferrite toroid frequency dynamic range is so wide. Thanks and respect for your answer. 73 :) TA9AAP
Paul, Wonderful work. Do you happen to sell these? You could open a shop on eBay.
Thanks! :) that's a good idea! Maybe I will sell them in the future ;)
Great UnUn watching for outdoors practical test. vk5cz ..
why don’t need to use a ground line? both 9:1 unun, right?
I used the feedline as the counterpoise and my body too. Wanted to try to use simplest antenna as possible.
Can I get two of them from you? I have Grunsig S350DL. it has 500 ohms unbalance input for MW AND SW. looking to use one at the radio side coupli8to 50 coax.
Hello. Thanks for replay. Please contact me via email 😉 73 Paul
what's the address? my email address is theodorelavernsears@yahoo.com.
Nice tidy and compact balun Paul. I like it a lot.
What type number are the toroid that you used for this please?
de2E0LFD
Unun not balun.
hi your a clover bloke . heres a challenge for you 6m to 160m small antanna . there a SIGMA EURO-COMM Magitenna 40 6m Multiband HF Wire Antenna 7.6m if you use a atu you can 80m to 60m with there wire anntenna . just wonder may be you can make . or make a better one . just asking thank you
It appears you have missed the point of what an UNUN's primary purpose is- that is to reduce common mode impedance on the outside of the feedline. What you have is a 9:1 transformer- whether it is an UNUN (unlikely as it is a single core) has not been measured, nor has the insertion loss been measured. SWR tells us nothing about the efficacy of an UNUN's primary purpose.
Dale W4OP
Hello Dale, thanks for watching! I am just a common HAM who want to make the antenna according to the model vk6ysf.com/unun_9-1_v2.htm
I am sure that 99% of us - common HAM's don't own such an expensive equipment which is able to measure efficiency or insertion losses. In my case I measured an impedance transformation from input 450ohm : 9 to output 50ohm = match with transceiver output SWR 1:1. What is wrong on it? 73, Paul
@@OM0ET There is a difference between measuring the SWR of a transformer and the common mode choking impedance of an UNUN. SWR measurements yield no information as to the efficacy of the device in choking off common mode currents. An UNUN is designed to reduce feedline shield radiation, transformers do not do this.
The Rig Expert series of antenna analyzers- and likely some other brands can measure common mode impedance.
Here is a short article on common mode and differential mode currents:
www.dxengineering.com/techarticles/balunsandfeedlinechokes/balun-basics-common-mode-vs-differential-mode
@@W4OP Thanks for info, but I dont have such kind of antenna analyser. Usually I use a current choke for fight against RF current in the feedline located right behind the transformer or UnUn.
@@OM0ET That is the correct solution- a well designed current choke (UNUN or BALUN) will decrease common mode. TRansformers in general do not. In addition though you need to know the common mode impedance of the antenna. As an example, NO UNUN or BALUN will be be effective at the end of a half wave antenna as the impedance is way too high for any real world UNUN's choking impedance to make a difference in common mode.
BALUNS and UNUNs have to be the most misunderstood device in amateur radio.
wow very nice! I would have a question! get some contact information. thank you very much!
Thanks! My email is hamradioslovakia@gmail.com
Thx...what iron core is worth using? Thanks
@@tamastoth464 You can use the Amidon FT-50-43 core
Thank you
22 meters of wire
Or 17.6 works well 😉👍