New Mini QRP 9:1 UnUn and Random Wire Antenna (Part 1) 

Hello. Thanks for replay. Please contact me via email 😉 73 Paul

what's the address? my email address is theodorelavernsears@yahoo.com.

Heh :-) thank you! It's my passion - this beautiful hobby... :-D 73 Paul

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

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: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-z9fJLo63ne0.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 ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-4n30XykCChY.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

Thanks! :) that's a good idea! Maybe I will sell them in the future ;)

I think that this small yellow toroid is wrong material for it. FT50-43 would be better with better results.

Unun not balun.

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

I used the feedline as the counterpoise and my body too. Wanted to try to use simplest antenna as possible.

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.

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

Thank you. :-) I believe in this antenna. :-) 73 Paul

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

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

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

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 😉👍

Or 17.6 works well 😉👍

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 :)

Thank you John! :-) I am curious how will this antenna work.. :-) 73 Paul

Thank you very much my friend 😉👍 73 Paul