Building a 9:1 UNUN With FT-140-43 Toroid.

Ғылым және технология

Building a 9:1 UNUN for a random-wire multi-band end-fed antenna using an FT-140-43 toroid instead of the usual T106-2. Presumably the ferrite toroid works better for the lower bands, 40 and 80m, and as well for the upper bands, I would guess up to 10m, not sure about 6m. It remains to be tested in an upcoming video. I should have measured SWR with a 470-Ohm resistor between ground and antenna wire but I forgot. A random wire by the way is any wire which is not a half-wave of any band to be used. The 9:1 UNUN usually requires a tuner.
End-fed antennas: • Clearing Up Some Confu...
EARCHI UNUN: www.earchi.org/92011endfedfile...
The field test link will be here as soon as completed.
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Пікірлер: 173

  • @oobihdahboobeeboppah
    @oobihdahboobeeboppah4 жыл бұрын

    I must say Gil, for us QRP mountain top and park activators, you are the wind beneath our wings. Your video posts inspire and encourage us to try new things and to warm up the ether!

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Thank you! Glad to be of some inspiration :-)

  • @richardwhitcroftkc3rrw63
    @richardwhitcroftkc3rrw632 жыл бұрын

    Gil.... your videos are always entertaining and educational.

  • @OH8STN
    @OH8STN4 жыл бұрын

    This was a magnificent video Gil, thank you for sharing 👍

  • @ratfunkblue
    @ratfunkblue4 жыл бұрын

    I have really enjoyed your videos. I am a newly minted ham. Got my general two weeks ago. I am now building the the earchi endfed for HF thanks to your videos. You are definitely my KZread Elmer! Cheers! ~ KI5JZV

  • @RadioPrepper

    @RadioPrepper

    3 жыл бұрын

    Glad to help!

  • @richardcooper38
    @richardcooper384 жыл бұрын

    Gil, First off I'd like to thank you for all your efforts in publishing these videos. They have provide a huge amount of instruction for me. I think I've bounced around almost every antenna type for my situation. My wife and I live in our 38' diesel motorcoach. There's limited space for antennas. I will be mounting a screwdriver antenna that I've had been dragging around for years but I've always have had reservations about it's performance. I've read and have listened to almost everything about these EFHW antenna systems over the last couple of weeks. I've been trying to figure out how to utilize a half wave length piece of wire and what I could do. One of the comments from another channel, he had mentioned that he put one of these antennas in his attic running all over the place and still achieved great performance. With this in mind I'm going to try to run the antenna wire from front to back several times and see how this will work. At this point I've got fairly good confidence that it'll perform well for my situation. Have you strung up anything similar with limited space in your trials of ham radio? Looks like most of your CW'ing is out in the beautiful open country. I look forward to your upcoming videos about these antennas. I need to get this put up on the roof of the coach and give it a try so I can get more sleep. Lol Steve Ellington put up a fantastic video of his studies on this antenna system. Well worth the time to watch. 73's Gil and thanks again!

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Not sure, that is a unique problem.. On a sailboat you have a mast.. You don't... The question is, do you want to operate while driving? Assuming that isn't the goal, honestly, a HWEF on a fishing pole type mast will serve you best, vertical or inverted V. I don't think it will work folded back and forth, but sometimes weird things happen in radio...

  • @richardcooper38

    @richardcooper38

    4 жыл бұрын

    @@RadioPrepper Gil, Being able to operate while driving isn't going to happen. Maybe on VHF. I'll have to give it a try and see. If nothing else I'll be able to throw it into a tree when trees are handy. I wouldn't mind if this floated and had a mast. Lol. If I was a able we'd be sailing the high seas years ago. I'll let you know how it works out.

  • @survivalcomms
    @survivalcomms4 жыл бұрын

    Cool beans ! The step drills (unibit) work great for plastic housings . When I have used a ground reference with an end fed it's really cool to see just how differently the antenna acts over varying soil conductivity. I have had good results with a counterpoise and a random length wire but the RX noise was greater. Thanks for sharing !

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Interesting thanks!

  • @riaanmaree1132
    @riaanmaree11324 жыл бұрын

    It's been more than 24hrs and we're all anxiously awaiting the test video! ;-)

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    It's coming!

  • @Adam-qd8jh
    @Adam-qd8jh Жыл бұрын

    I decided to make this design and it worked really well for the cw range on the 40 meter band. Using 29 feet of speaker wire and a 32 foot counter poise. Though I haven’t heard any voice, my water fall on my SDR was packed with cw. I live in between two hills at the bottom and get really bad propagation. But This was my first antenna project after 2 years of messing around with the balun that came with the nooelec SDR. I think I just need to get my antenna higher or lengthen it as I only put it up about 15-20 feet. But I’m excited because I’ve never seen so many signals before. And also I tried using it at night so maybe this is why I haven’t heard any voice on the band. But I can tell this Antenna will pair perfectly with my QRP cw pixie. Thank you!

  • @RadioPrepper

    @RadioPrepper

    Жыл бұрын

    Make sure you check the SWR if you transmit with it. You probably will need a tuner..

  • @chipandrews2892
    @chipandrews28924 жыл бұрын

    Another awesome video Gil...thanks for sharing. I must say that I really enjoy your project/build videos! You explain what you are doing so very well and seeing you do it really puts the cherry on top. Thanks again! Cheers! De KL7CA

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Thanks Chip!

  • @TheDgdimick
    @TheDgdimick4 жыл бұрын

    Gin, you SO need that 3d Printer. You're the one that recommended the Ender 3 to me, and I've been happy with it for 8 months.

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    And I still need to buy it! Darn, you beat me to it!

  • @TheDgdimick

    @TheDgdimick

    4 жыл бұрын

    @@RadioPrepper I've bought 2 so far, and normally they are running pretty much all the time, except this week, I'm studying for my Extra Test on Saturday.

  • @ianboard3555

    @ianboard3555

    3 жыл бұрын

    Completely agree. I bought one a couple of months ago and have been super happy with it. I like the fact that you can start with the basic model and upgrade it easily (better controllers, extruders, etc...).

  • @g4okt
    @g4okt4 жыл бұрын

    'I just can't help myself...." Yes, I know that feeling! Nice vid, looking forward to the testing. I like to use type 61 ferrite for 10 and 6m. 73, Keith

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    61 would be the right choice for those bands yes. Maybe 52 for 10m...

  • @georgealbertacanadaeh1038
    @georgealbertacanadaeh10382 жыл бұрын

    Thank you, Excellent! I always wanted to see how this was actually done! I have seen and read articles but actually seeing makes it all come together. Thanks again, George Alberta Canada Eh

  • @RadioPrepper

    @RadioPrepper

    2 жыл бұрын

    Glad it was helpful!

  • @alexandretsilefski2308
    @alexandretsilefski23084 жыл бұрын

    Hello Gil. I enjoy your videos. The transformer you discribed for the CB band is working really well, I had contacts with Perpignan and London from the village I live, not too far from Strasbourg. Many thanks! Have a nice week-end!

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Excellent!

  • @robthomas8680
    @robthomas86802 жыл бұрын

    great article - got the parts - building one now - thanks!

  • @raulponce6276
    @raulponce62764 жыл бұрын

    Nice! I really hope it works! I also bought one and it arrived for me these days. It is a very low permeability (ur = 10) powdered iron specified as low losses in "all frequencies" (??). I have been researching, and it really makes sense that it is a core with lower losses at high frequencies, since the material allows less effect of magnetic hysteresis and circulation of Foucalt currents. The phenomenon is obseveed in induction furnaces, where the core must necessarily produce heat. conversely, especially in QRP, any loss value becomes significant. than, this core would be better. In my case, I will have to wait a little longer to test because I live in an apartment on downtown. I wait for your opinion in another video too! haha

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Wait for the second video in a day or two...

  • @milfamily193
    @milfamily1934 жыл бұрын

    you're awesome! I watch your videos a lot. I actually ordered 3 of the 140-43's last week. They arrived in pieces! The seller didn't package them well at all. But, he loss. Ordered 3 more form a different seller. We will see. Hope it all worked out. 73s from KC2JDR

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Better use them for a 49:1 transformer..

  • @DrenImeraj
    @DrenImeraj4 жыл бұрын

    You should consider getting a step drill bit. They are extremely effective for opening holes in plastic boxes. Thanks for another great video!

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    I have one, but I need a smaller one!

  • @jimthvac100
    @jimthvac1004 жыл бұрын

    Great Video Gil, I look forward to your comparison of these two 9:1 UNUN's using your new Minion. Lol of course we will enjoy the video regardless what radio you decide to test them with :)

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    The second video will be out in a day or two!

  • @davidsradioroom9678
    @davidsradioroom96784 жыл бұрын

    I want to build an unum. Looks like fun and you get something useful from it.

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Yep, wait for the second video to choose your toroid! Coming up in a couple days...

  • @ae1tpa92gwtom2
    @ae1tpa92gwtom24 жыл бұрын

    Gil, ur great, n everyone , im sure everyone likes the look on yr face, when u cant help yrself, u give all of us education, courage to do it, n ways to enjoy the hobby,.. good on ya,.. 73 my friend

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Thank you! Always nice to hear :-)

  • @user-mt2qn4yp8w
    @user-mt2qn4yp8w4 жыл бұрын

    Man that sucks when the box broke. Keeping fingers crossed that it works. Great video. Take care. , KG7LOI Clark. 73's

  • @n8nkqrp595
    @n8nkqrp5954 жыл бұрын

    It's all about Al value and thus the minimum usable frequency of the unit. And to a secondary matter- self-resonances of the UNUN with no load connected. T106-2 has an Al value of only 135, severely limiting it's low band use, as you mention. For what it's worth, the Al value of the FT140-43 is 885, 4 times that of the iron core, giving you 16x the inductance per turn. Much to consider. 73

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Great info thanks!

  • @hobbyrob313
    @hobbyrob3134 жыл бұрын

    YES yes yes this is not strange what happens here! drilling holes in this way requires for it! but don't say that these boxes are junk, that's not fair! ( And +1 for Denis Dimick!!! ) Greetings from NL Rob

  • @chrisb3989
    @chrisb3989 Жыл бұрын

    Very neat build well done……..

  • @markg6jvy135
    @markg6jvy1354 жыл бұрын

    “Toroids, washers wingnuts and 22awg wire, everything to make a man happy” 😂classic line Gil 😂👏 I find a cone step drill sometimes prevents that snagging of fluted drill bits when going into thin material.? Great video as always 👍

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Worst thing is, I have one!

  • @ssubaihi
    @ssubaihi4 жыл бұрын

    I am HZ1-si (Suhail) from Saudi Arabia First, thank you so much for this Great channel .. I heard that some (Core materials) have some advantages over others, Particularly in (Receiving mode) which let your antenna has less noise.. Perhaps That's is why some of the End-Fed producers marketing some of End-Fed antenna as a ((SWL End-Fed antenna only) with limited TX Power capability .. Hopefully you shed some light on such (the important secret) .. I say this because I made myself End-Fed Half-Wave antenna, it is very good antenna, I have no big problem in (Transmit Mode) as I can compensate for Far Away DX station with a little push of TX Power ... However, I am still struggle in Receiving Mode especially with some weak DX signals .. Besides, I don't have much (Horizontal space) for the "Wonderful Beverage Antenna" .. By the way ... Generally Speaking ... which is better in (Receiving Mode) .. (9:1 Un-Un*) or (49: 1 EFHW**) ? considering Both Antenna have the same Length @ same Band .. *considering a proper Ground or Counterpoise applied.. **Considering a proper Line isolation applied.. Please Help ..

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    That is a very good point. I did not test noise levels... The second video will be out soon.

  • @HKey_Root
    @HKey_Root3 жыл бұрын

    'Don't make one yet as I don't know if it works'. Brilliant. Love it.

  • @RadioPrepper

    @RadioPrepper

    3 жыл бұрын

    Turns out, it doesn't!

  • @HKey_Root

    @HKey_Root

    2 жыл бұрын

    @@RadioPrepper 😂

  • @BarefootBeekeeper
    @BarefootBeekeeper2 жыл бұрын

    A stepped bit makes a better job of holes in plastic boxes than a twist bit, and can be used by hand, without a drill.

  • @AndrewBryantPianoTuner
    @AndrewBryantPianoTuner Жыл бұрын

    When you twisted the 2 wires together did you remove the insulation ?

  • @mabo4848
    @mabo48484 жыл бұрын

    TNX !

  • @johnk8091
    @johnk80914 жыл бұрын

    Great instructions to build the 9:1 "OON OON". I still far prefer the 49:1 and EFHW. Looking forward to your testing video to see how the two compare

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Me too..

  • @mikes6844
    @mikes68444 жыл бұрын

    Try putting a clamp both sides of the box before you drill the hole as it should stop it from splitting on the basis you are not using too much downward pressure. Or use a vice. Another very useful vid, I can't keep up with you! Just finished building a 49:1 balun. Will be testing some EFHW wires with it over the weekend. We are still in lock down and will be for a while longer, BYOTA (Back Yards On The Air) for me. Conditions quite good for a little QRP. Take care... 73 de M0AZE

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    I should have done that!

  • @WillemvanderHouven
    @WillemvanderHouven4 жыл бұрын

    Nice video Gil, but could you explain te windings again with a total wind of the emailed copper wires i count 8 turns ? at 5:30

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Count the turns on the inside of the toroid... Every time the wire goes through the code is one turn.

  • @luismirandakunert3475
    @luismirandakunert34754 жыл бұрын

    Nice, congrats DO you know where can I get(buy) a set of this toroids to make inductance as my pleasure? Thank you

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    I get them all on Ebay..

  • @napomania
    @napomania Жыл бұрын

    good job . next time try to use a conic drill hole 🙂

  • @jamdiversified9698
    @jamdiversified96982 жыл бұрын

    Quick tip, If you want to get hot glue off of something, spray it with isopropanol (IPA) and it will come right off clean.... From smooth surfaces at least.

  • @jamescoffey5225
    @jamescoffey52254 жыл бұрын

    I have always found that when drilling into plastic (boxes) I use a smaller drill bit or a few smaller drill bits and then start drilling, gradually increasing the diameter of the hole until I get to the size of drill bit I need for the BNC or whatever attachment I am using. Could you have made better use of a metal box for the UNUN if you could procure one for a reasonable cost? I have never tried using a metal box for a balun or an unun. AE5ZX

  • @jamescoffey5225

    @jamescoffey5225

    4 жыл бұрын

    Of course I am usually too lazy and end up just drilling a hole of the appropriate size in the plastic box, and then just hope for the best. 😊

  • @Steve-GM0HUU

    @Steve-GM0HUU

    4 жыл бұрын

    For plastic, I drill a small hole then use a reamer to enlarge to exactly the right diameter. This way you can make holes of any size (3mm to 13mm) with just one 3mm drill bit and a reamer.

  • @riccardomilan
    @riccardomilan Жыл бұрын

    Thanks so much Gil! is it mandatory to remove the insulation before join and weld the wires correct? I'm doing a similar UN:UN with 16:1 9:1 and 4:1

  • @RadioPrepper

    @RadioPrepper

    Жыл бұрын

    Hi, oh yes.

  • @scottcarter9975
    @scottcarter99754 жыл бұрын

    Another good video Gil. Thanks. Question: I have a spare FT-82-43. Do you think it would work for a 9:1 for portable up to 10 watts? Thanks, Scott kw4jm

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    I will be able to tell you in a few days... Wait a bit... I would make a 64:1 transformer...

  • @radioastronomy2001
    @radioastronomy20014 жыл бұрын

    Like always very interesting video. Thank you! You can test it by loading it with a 470Ohm (ideally 450Ohm) resistor and running antenna analyzer. It should show around 1:1 SWR across all bands. I used a yellow core (+-4cm in diameter) from an old PC power supply. It does work well from 80m to 10m. The materials seems to be "#6".

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Not the 9:1. The 9:1 needs to be tested with a resistor in the 400-600 Ohms range. A 49:1 or 64:1 however is tested with a 2500 to 4700 Ohm resistor. See: kzread.info/dash/bejne/Yq56mcR9n9TRd5c.html

  • @radioastronomy2001

    @radioastronomy2001

    4 жыл бұрын

    @@RadioPrepper Normally you can not buy 450Ohm resistor but 470Ohm seems to be close enough where 400-600Ohms seem to be too far. I agree for 49:1 transformer you would need something like 2450Ohm but again you can not buy one exactly like it. Most likely you would have to combine 2.2kOhm with something else (330Ohm) or use 2.7kOhm. So I still think 470 Ohm is a good approximation when testing 9:1 unun. 470 Ohms / 9 = 52.2 Ohms. Where 400/9=44.4 (my "." is yours ",")

  • @ricktafied

    @ricktafied

    Жыл бұрын

    @@radioastronomy2001 Use a pot and set it to 2450 ohms?

  • @radioastronomy2001

    @radioastronomy2001

    Жыл бұрын

    @@ricktafied Good idea. Thanks.

  • @daveduffy2292
    @daveduffy22923 жыл бұрын

    In some vlogs I noticed that they use insulated wire. Does it make a difference

  • @RadioPrepper

    @RadioPrepper

    3 жыл бұрын

    Not with material 43. Note that enameled wire like I use is insulated.

  • @Pauldeva
    @Pauldeva4 жыл бұрын

    What are dimension of the box pls, '73 de YO2MMJ

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    50x80x26mm.

  • @toddmathews7828
    @toddmathews78282 жыл бұрын

    I've found that using a forstner bit works really well for drilling through those cheap plastic boxes. Sadly, it took me more than one box to discover this.

  • @andreVE4BK

    @andreVE4BK

    2 жыл бұрын

    I use a stepping bit… slowly. Never had a breakage

  • @19134ANDY
    @19134ANDY3 жыл бұрын

    Nice video, do you have one on how to make a 6:1 unun

  • @RadioPrepper

    @RadioPrepper

    3 жыл бұрын

    I have one on the 9:1.

  • @AndrewBryantPianoTuner
    @AndrewBryantPianoTuner Жыл бұрын

    When you twisted the 2 wires together did you remove the insulation or do you leave it in place ?

  • @RadioPrepper

    @RadioPrepper

    Жыл бұрын

    I left it.

  • @gordselectronicshobby3853
    @gordselectronicshobby38534 жыл бұрын

    Step drills would b better to use as well as a reamer for fine cuts.

  • @calvinlong1265
    @calvinlong12652 жыл бұрын

    Do you know if you can safely use an unun on a dipole?

  • @RadioPrepper

    @RadioPrepper

    2 жыл бұрын

    You would not use an UNUN on a dipole, as it makes no sense to do so..

  • @andreVE4BK
    @andreVE4BK2 жыл бұрын

    Gil… if you identify your wires individually (you’ll need 2 markers) before you start winding, you will save time and effort at the end. 73 Andre/M0RAV

  • @MrLittlmike22
    @MrLittlmike224 жыл бұрын

    great video as always - it woudl be greta to move up to 1:49 too!

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    I definitely do prefer 49:1 with a half-wave wire..

  • @tanglewoood
    @tanglewoood2 жыл бұрын

    Builders might like using a step drill with 1/32" steps. They are available from a number of sources including Amazon.

  • @rickmckee6698

    @rickmckee6698

    2 жыл бұрын

    Just use a step drill !

  • @RadioPrepper

    @RadioPrepper

    2 жыл бұрын

    Yes, I have one..

  • @captainmarvel6031
    @captainmarvel60314 жыл бұрын

    Thanks for the video! One question, do you know what guage wire to use for it to handle 100 watts, or would I need a different toroid also?

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    It should take 100W, 1mm wire.

  • @barrykery1175

    @barrykery1175

    3 жыл бұрын

    @@RadioPrepper The wire can easily handle 100 plus watts. The heating of the core is the limiting factor. Depending on what UnUn or balun you make, I've already run 1500 watts using an FT 140-43. Yet a 64 to 1 UnUn for a HWEF won't handle more than 50 watts without getting hot. Barry, KU3X

  • @RadioPrepper

    @RadioPrepper

    3 жыл бұрын

    And risking permanent damage...

  • @tackanderson4270
    @tackanderson42702 жыл бұрын

    How can you use a multi-meter to test "short" when all your wires are touching and already shorted"? Unless the "lacquer" wire coating is enough to separate them and keep them from shorting out?

  • @RadioPrepper

    @RadioPrepper

    2 жыл бұрын

    The enamel does insulate the wires but the circuit itself is such that everything is a DC short, so a multimeter is useless. It is however not a short for AC at the intended frequencies.

  • @tackanderson4270

    @tackanderson4270

    2 жыл бұрын

    @@RadioPrepper Assuming those frequencies are isolated (in bandwidth). I'm assuming this is what you meant as "intended frequencies". However, once ground is introduced to A/C, a short results, even an isolated ground (not sure of a radiated or ground plane). So this means under operation, those wire must be isolated? Testing however, must be done with an O scope. I do think you said that the multi M would be useless, so point understood.

  • @RadioPrepper

    @RadioPrepper

    2 жыл бұрын

    Actually I should have said "the turns are insulated," it really is only one wire... See my construction videos...

  • @tackanderson4270

    @tackanderson4270

    2 жыл бұрын

    @@RadioPrepper Sounds great....

  • @joecraft4409
    @joecraft44093 жыл бұрын

    Hey Gil, today I heard that it is not recommended that one use a RED toroid to make unun. I have to go back and read the article for understanding.

  • @RadioPrepper

    @RadioPrepper

    3 жыл бұрын

    Well, it's not recommended but it works better so...

  • @midwestavaitionmx5503
    @midwestavaitionmx55034 жыл бұрын

    I’m brand new to hf, love the information in all of these videos. Also most interested in portable setups. Couple of questions, Do BNC and so239s serve the same purpose? Where do you get your materials for your projects? Thanks 73deW0DJW

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Hi, Ebay.. BNCs are just smaller and easier to use; same purpose.

  • @technicmasters7936
    @technicmasters79362 жыл бұрын

    Does this work with FT14-43 toroid or would i need to have a different number of turns? And if so, how many?

  • @RadioPrepper

    @RadioPrepper

    2 жыл бұрын

    No, a 9:1 does not work well with an FT-140-43. Use a T130-6.

  • @technicmasters7936

    @technicmasters7936

    2 жыл бұрын

    @@RadioPrepper Probably just a typo, i meant FT14-43, i think i have a T130-6, ill give it a try, thanks

  • @RadioPrepper

    @RadioPrepper

    2 жыл бұрын

    I never heard of an FT14-43... See the EARCHI (Hawai Radio Club) pdf file on the matter...

  • @technicmasters7936

    @technicmasters7936

    2 жыл бұрын

    @@RadioPrepper oh, sorry FT114-43

  • @technicmasters7936

    @technicmasters7936

    2 жыл бұрын

    @@RadioPrepper Would FT114-43 work?

  • @flipster7285
    @flipster72852 жыл бұрын

    I love watching your videos. I am learning quite a lot and I am now starting to build a few things to play around with. I do have a few questions though, maybe you could help me get some clarity. 1) what would the max power be that I can put through this FT140 9:1 unun? If I want to go up to a max of 500w, would I be better off with a FT240-43 or perhaps 2 stacked FT240's? Unfortunately toroid cores useful for RF are not easily available in South Africa and they are fairly expensive when we do get them so I do not want to buy loads of cores that will not get used. 2) when it comes to winding...... Adam (K6ARK) built a small 9:1 on an Ft50-61 but he does not use 3 seperate wires, he winds that with a single continuous wire. (I built that qrp antenna and it works really well). Would that same technique work for bigger unun's or would it be better to use the seperate wires and solder them together after winding? Looking forward to more quality lessons from Master Gil!

  • @RadioPrepper

    @RadioPrepper

    2 жыл бұрын

    All right: 1. You don't build a 9:1 UNUN, which is for random wires with a 43 material core. Those are for 49:1 or 64:1 and half-wave wires. Watch the following video:

  • @RadioPrepper

    @RadioPrepper

    2 жыл бұрын

    kzread.info/dash/bejne/Yq56mcR9n9TRd5c.html

  • @RadioPrepper

    @RadioPrepper

    2 жыл бұрын

    If you want to build a 49:1 or 64:1 for a half-wave wire, you will need to stack three FT-240-43 cores. I do not recommend using a 9:1 with a random wire for high power.

  • @RadioPrepper

    @RadioPrepper

    2 жыл бұрын

    2. Yes, but need to test... 3. 500W is useless. Anything above 30W is a waste of electricity and not needed a vast majority of the time. Invest in antenna building materials and knowledge instead of an amp.

  • @carlossilva.k2wc.542
    @carlossilva.k2wc.5422 ай бұрын

    First, thank you much for sharing your videos with all us, I have a quick question, How much power can this core hold in digital modes (FT8)? Is 30 or 40 watts okay?, Thank you in Advance,73 de K2WC

  • @RadioPrepper

    @RadioPrepper

    2 ай бұрын

    Hi, 30 should be OK, though with FT8 5W is enough. BTW 43 material isn't good for a 9:1. Check my other videos. Use a #2 red core.

  • @carlossilva.k2wc.542

    @carlossilva.k2wc.542

    2 ай бұрын

    @@RadioPrepper Thank you for your prompt answer, your are talking about the T200-2 toroid?

  • @RadioPrepper

    @RadioPrepper

    2 ай бұрын

    Yes, or T130-2. I don't remember which one I used, it's in a video..

  • @robthomas8680
    @robthomas86802 жыл бұрын

    um - step drills - $12 on Amazon or your locate hardware - don't leave home without 'em! :)

  • @StephenFarthing
    @StephenFarthing4 жыл бұрын

    You will find it easier, and safer, if you use a step drill bit rather than the ones you have. I've probably a spare one if you want it.

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Worst thing is... I have one! Thanks though :-)

  • @thierryruiz9205
    @thierryruiz92054 жыл бұрын

    Bonjour Gil, très bonne vidéo sur la fabrication de transformateur, aurais tu la possibilité de joindre les liens pour l'achat des toroïdes, merci d'avance, 73 F1RJC

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Sur Ebay, fais une recherche, il y en a plein...

  • @thierryruiz9205

    @thierryruiz9205

    4 жыл бұрын

    Bonjour Gil, je viens de le faire, j'ai trouvé mon bonheur, merci Thierry

  • @HKey_Root
    @HKey_Root3 жыл бұрын

    Actually could someone explain why this isn't a balun? Still learning.

  • @RadioPrepper

    @RadioPrepper

    2 жыл бұрын

    BALUN is balanced-to-unbalanced. UNUN is unbalanced to unbalanced. Example: An end-fed wire is unbalanced, coax is unbalanced, so you use an UNUN. A dipole is balanced, coax is unbalanced, so you use a BALUN.

  • @HKey_Root

    @HKey_Root

    2 жыл бұрын

    @@RadioPrepper Of course it is. My bad. So twin flex from say a homemade Magloop would need a balun? 9:1?

  • @RadioPrepper

    @RadioPrepper

    2 жыл бұрын

    What is twin flex? Are you sure you mean a magnetic loop, not a regular loop? Mag loops don't need impedance matching other than the big capacitor in the loop...

  • @HKey_Root

    @HKey_Root

    2 жыл бұрын

    @@RadioPrepper We're now talking at cross purposes. Thanks for your input.

  • @laurentboussuge7368
    @laurentboussuge73684 жыл бұрын

    Bonjour merci pour vos vidéos pouvez-vous la faire en français ?

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    La seconde sera aussi en Français!

  • @laurentboussuge7368

    @laurentboussuge7368

    4 жыл бұрын

    @@RadioPrepper merci

  • @svtelos4726
    @svtelos47263 жыл бұрын

    Its possible to punch holes in thin plastic, with an ordinary hand hole punch. A single, not the triple for notebooks. Or, for thicker plastic, a leather hole punch. much cleaner and less scarier than watching Gil and a drill press.... :) !!

  • @RadioPrepper

    @RadioPrepper

    3 жыл бұрын

    Not that kind of plastic but those work very well on Altoid cans!

  • @svtelos4726

    @svtelos4726

    3 жыл бұрын

    @@RadioPrepper Then, we should put a nice small drill press vice on your Amazon Wish List for Xmas! Thanks for your videos. I just got my General License and am looking forward to hearing you on the radio. Alas, Im in San Diego. Your vids are both entertaining and very instructive. Thanks. :)

  • @RadioPrepper

    @RadioPrepper

    3 жыл бұрын

    Thanks! I have one but it's up North at my parent's...

  • @Ryo_Saeba
    @Ryo_Saeba4 жыл бұрын

    Bonjour, je vous ai entendu au col de coursegoule alors que vous étiez au col de vence. Vous avez donné l'adresse de votre chaine, je me suis donc permis de vous écrire pour vous dire le bien que je pense de votre chaine et que la liaison avec un petit talkie était sans fioriture

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Super merci! Je suis de temps en temps à l'écoute sur le relais du Mont Agel et Vial..

  • @oobihdahboobeeboppah
    @oobihdahboobeeboppah4 жыл бұрын

    The Fairite type 43 is not the best material for the lower bands on HF. If you look up the specs at Palomar Engineers you will see that type 43 is better from 20m up possibly as high as 6 m. Type 31 is a better material covering 160 meters to 6 meters. Type 41 will work but not as well.

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    In theory yes, but in practice, everything I have ever found that works points to 43, 52 and 61 for 80 to 6m, with 31 used for chokes. Maybe the choke vs transformer is the difference...

  • @oobihdahboobeeboppah

    @oobihdahboobeeboppah

    4 жыл бұрын

    In recent months, I built 9:1 ununs using both. Afterwards, I used a 50Ω dummy load at the output of the unun, and my analyzer at the input. What I found was that in both units, the response curves almost paralleled the Fairite specs exactly. I've used both for QRP, and both work, though the 31 works better: Louder signals on receive and better signal reports on transmit. I'll have more time to test with the warmer weather. Ahhhh, the fun of Amateur Radio!

  • @Steve-GM0HUU

    @Steve-GM0HUU

    4 жыл бұрын

    @@oobihdahboobeeboppah just wondered please - on which bands did you find the 31 was better?

  • @mortimersnerd801

    @mortimersnerd801

    2 жыл бұрын

    @@RadioPrepper Your correct Gil...and Palomar sell 31 material specifically for common current and noise chokes... other than 160 and maybe 80, meters... 31 material is not recommended for the high bands.. took in their seminar at the Yuma hamfest. in how they explained this.

  • @expert244
    @expert2444 жыл бұрын

    Now I want to make an UNUN.......

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Make a 49:1 transformer rather..

  • @warplanner8852
    @warplanner8852 Жыл бұрын

    Gil, French don't say "merde" anymore? 😅 For the bigger holes, use the a reamer, Gil. A little more work bit minimizes the chance of shattering. 72/73 de William, k6whp dit dit

  • @rickmckee6698
    @rickmckee66982 жыл бұрын

    An FT140-61 core works much better 10 thru 80 meters.

  • @jamesgeorge1709
    @jamesgeorge1709 Жыл бұрын

    Get yourself some step bits you'll never go back to metal boring bits.

  • @corbeijersbergen9999
    @corbeijersbergen99994 жыл бұрын

    Gil, don't blame the cheap plastic box, blame the wrong type of drill..

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Or myself.. ;-)

  • @M0RMY
    @M0RMY4 жыл бұрын

    Gil Brilliant as usual. I really enjoyed this. I have emailed you a message about a project you may be interested in conjunction with Callum DX Commander. Tom M0RMY

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    I'll check that address thanks!

  • @Subgunman
    @Subgunman3 ай бұрын

    Old joke about thread lockers, "Cross threading works better than locktite". NOT! I found that buying and using the longer and narrower step bits will not destroy plastic cases, the fatter and shorter step bits will cause cracking of cases, steps too large.

  • @harrymudd6547
    @harrymudd654722 күн бұрын

    It's only eight turns.

  • @RadioPrepper

    @RadioPrepper

    22 күн бұрын

    And?

  • @harrymudd6547

    @harrymudd6547

    20 күн бұрын

    I thought they said it had to be 9 turns?

  • @gilgsn

    @gilgsn

    20 күн бұрын

    I don't remember, but 9:1 does not necessarily mean nine turns..

  • @harrymudd6547

    @harrymudd6547

    20 күн бұрын

    ​@@gilgsnI'm just trying to understand how this works. It looks like 8 turns to 16 turns. How do i get 9 to 1 impedance match from a 2 to one turns ratio?

  • @RadioPrepper

    @RadioPrepper

    20 күн бұрын

    @harrymudd6547 I don't know on a trifilar transformer, only how to calculate it on a regular bifilar transformer...

  • @kennethschultz6465
    @kennethschultz64654 жыл бұрын

    Hot glue ain't water tight .. you truly want ppl to fail

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    It doesn't need to be watertight. This is for temporary portable operations. Even for a permanent installation, these boxes should be vented to avoid condensation.

  • @kennethschultz6465
    @kennethschultz64654 жыл бұрын

    So you are a Fan !! Well I'LL never be !! I tryed 5 difrent designs Not one of Them worked in any satisfictory way !! It's a crappy antenna !! In any way.. waste of time

  • @RadioPrepper

    @RadioPrepper

    4 жыл бұрын

    Fan of hal-wave end-fed antennas, not random-wire antennas with a 9:1 UNUN... What kind did you try and how?

  • @warplanner8852
    @warplanner88523 жыл бұрын

    Gil, I am told that you can TWIST the wires with no adverse effect. I am going to build a one and I will report back. de k6whp

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