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Antenna Whisperer - K7RAW
Приєднався 24 жов 2022
This channel is all about antennas and systems, primarily for ham radio. It is a series of seminars on a variety of topics from beginner to advanced, all in an organized and digestible format with lots of practical examples.
Відео
K7RAW OCFVD Update
Переглядів 2242 місяці тому
Here are some ideas for you to finish off your OCFVD in a slick way.
K7RAW Self-Contained Off-Center-Fed Vertical Dipole (OCFVD)
Переглядів 4,4 тис.5 місяців тому
This is the perfect companion antenna for a POTA activation or any field HF operation. It operates 40m-10m and everything in between. The telescopic whip, tent stakes and guy tiedowns are all contained inside the 2" PVC tube. Add a tiny ATU-100 on a short piece of coax and you have a fully-tunable multi-band antenna. MOTIVATION This 40-10m compact antenna is intended for very fast setup and tak...
TennaTalk #12a BalUns UnUns Chokes
Переглядів 3295 місяців тому
This is the Presentation I gave at HamCon Zion in July 2024. It lays the groundwork for understanding Common Mode Chokes, BalUns and Ununs. Part 12b is the presentation that preceded the hands-on Workshop immediately after the above Presentation, discussing the design, construction and testing of these devices. The link to the PDF of all the slides is at the end of each presentation.
TennaTalk #12b BalUns UnUns Chokes
Переглядів 1585 місяців тому
This is the Presentation that preceded the hands-on Workshop at HamCon Zion in July 2024, discussing the design, construction and testing of these devices.
TennaTalk #8 Q&A SDR and Diversity Receive
Переглядів 1388 місяців тому
This is the online discussion about Diversity Mode Receive & SDR
TennaTalk #11 John Protune W6NBC Ladder Line
Переглядів 2568 місяців тому
John tells us about unusual uses of Ladder Lines.
TennaTalk #7 John Portune W6NBC Slot Antennas
Переглядів 846Рік тому
TennaTalk #7 John Portune W6NBC Slot Antennas
Slick remote auto-tuner setup for Yaesu HF radios
Переглядів 1,5 тис.Рік тому
If you own any of the Yaesu radios that support their ATAS screwdriver antenna tuner, this solution will work for you. Using the LDG RT-100 remote antenna tuner, you don't need a power cable or even the controller box they provide. Just put the radio into ATAS mode, press the "multi-function" tune button under the display, and the unit will first go thru "INIT" mode for a minute or two. Then it...
K7RAW 80m-6m Elevated Auto-Tuned Vertical
Переглядів 1,3 тис.Рік тому
This 80m-6m Elevated Auto-Tuned Vertical is perfect for POTA and Field Day where you want to get your radiating element above the tree-tops. Works with any radio and drives the ATU through just the coax itself. Typical SWR less than 1.2 on all bands. Has 2,000 ATU memories so the more you use it the more it learns. Uses latching relays to stay put on last frequency even when power is turned off...
TennaTalk #6 Antenna Modeling with EZNEC & SimSmith
Переглядів 580Рік тому
TennaTalk #6 Antenna Modeling with EZNEC & SimSmith
Tiny NoodleTenna for HF Limited Spaces
Переглядів 45 тис.Рік тому
Tiny NoodleTenna for HF Limited Spaces
Old crap
FT140-31 not available...... could you have meant another type of toroid?
Any way to make it multi band like a EFHW 8010?
Thanks for your contribution to the hobby. Why not show a sweep with an antenna analyzer to demonstrate the bandwidth and SWR? Also an on-air A-B comparison with a standard horizontal dipole would be a bonus.
Very Kewl. I used to listen to 500 khz all the time. I had a huge horizontal loop that was resonant for 500 khz and at night I could hear shipboard radio operators doing 60 wpm thousands of miles away.
Thank you for you knowledge aiding in understanding this complexity of un uns.
You just peeked my interest again in home brewing wired antennas. Thank you.
Great video Ty
Considering your design for attic use in my HOA. What are some things you might recommend to enhance operation on 40M? TIA!
I did something vaguely similar for wideband/shortwave reception. I am trying to research to see how I can improve it. I wound about 200 feet of #28 magnet wire around a piece of 2.5" PVC pipe going in one direction starting at the center, and did the same from the center going the other direction with another piece of #28. fed the two center wires to a 1:1 UNUN and connected that to my SDR. It works shockingly well. I just winged it though. I'm looking to play with techniques and wire lengths to see how it comes out. Very little information out there on this type of thing.
I came across your video while looking for ways to build an inexpensive dipole for 40M. I'm a newer ham and was curious if this would work for NVIS. 73
This is great! I’d love to watch a build video.
the suns uv rays will destroy the pool noodle in short order
Can I get complete spect?
Nice work Rudi 👍
Just want to tell you that your channel is reacting OZ Country 73 De OZ3NO I am going to watch your Tenna talk play list this week
Well done Rudi. This looks great. It would be interesting to see what effect there is by relocating the choke to the input side of the tuner and letting the whole thing float above GND. This is what I've done with my AH-4. (I also have to choke the control cable on that ATU) Keep up the excellent work! 73 OM
got to try this . them thunder and lightning days . just swop over and disconnect the outdoor danger . thats got to be a winner
saludos Rudy, me interesa mucho tu diseño de antena pues está sería mi salvación pues dónde vivo no hay el más mínimo espacio para antena ni dentro ni fuera de casa. Necesito información para su construcción ya q es la ideal para mis condiciones. Gracias, 73'sDX CO2JH
Love it!!!!! AE4YW
Hi Rudy, Very Interesting design. What is the Bandwidth like, is it High Q or does it cover the 20Meter band pretty well? I'm wondering if it would be a good attic antenna.
It has all the wide bandwidth characteristics of a typical dipole. I would NOT recommend putting in the attic as it already is challenged a bit on receive. Place it on your porch or balcony.
This is one of many things about Mateus radio…guys like you that never rest and continue to innovate. Thanks!
Thanks 73
Thanks for sharing your knowledge. KF0MOE
Cordial greetings colleague Ruddi, I have been pleasantly surprised with this antenna project, could I publish a construction scheme of it, I think that there are many of us who are interested in a multiband antenna for small spaces. 73's Dx's
Please share whatever you learn. All will benefit.
Does HOA mean your a homosexual? 🤔
I tried Tena ladies but didn't receive shit 🤷🙄
Maybe get it up higher "in the clear"?
I am a new Ham, do you have to use the LDG RT-100 remote antenna tuner? Or will any tuner work. What should I look for?
As far as I know, only the LDG tuners emulate the Yaesu ATAS antennas that need power and RF.
SIMPLY GENIUS!
Not really..just a standard dipole wrapped around pool noodles 🤷🙄..in fact, I think it's a pretty bad design, I can see those noodles melting if you run over 30 watts through that wire ..
I've pumped well over 100W into this (once tuned) and never saw signs of heating. I use 18 AWG hookup wire which is rated to handle hundreds of watts. The resistance of such a relatively short length is VERY low. Before you criticize, maybe you should first try building, tuning and testing one for yourself. You may be surprised. It IS a "compromise", but if you live in an HOA or on the 5th floor with only a balcony, it will get you on the air.
What would you think about using an air wound coil approximately 6 in diameter made from 1/8 in copper tubing (self supporting), with mechanism to expand or contract the coil, thereby changing its inductance enough to not only tune across the band, but also change from band to band ?
WOW, that would be big and HEAVY, not to mention pricey for all that copper.
Sounds complex and heavy (and maybe even expensive).
Can you demonstrate using it on a radio?
I will try to do a followup with a field test. Would put all the doubters to bed.
Looks like a nice homebrew antenna for portable operations.
Got a link for the whip? I have not found one that is not 10mm thread instead of the 3/8 24 that I already have many things for. Even a good source of 3/8 24 to 10mm adaptors would be great! Thanks for open sourcing this!
Go to www.mcmaster.com and search for P/N 92499A793 which is a stainless adapter M10x1.5-F to 3/8-24-M. Cost is about $8
Nice home brew, well done.
_”(scale the lengths for other HF bands)”_ Now if I can just find a *400 inch* long, *24 inch* diameter pool noodle for 80 meters … 😀 Or maybe a _”Slinkie™ dipole”_ *73 de AF6AS*
Yeah, I've built and tested a number Slinky dipoles but the biggest downside is that the spring steel Slinky has WAY too much ohmic resistance (otherwise known as a toaster coil) for my tastes.
@@rudiwiedemann8173 _<Gears in brain still turning>_ ... I wonder how much the efficiency would improve if someone had the ability to *COPPER PLATE* the Slinky? Factoring in _skin effect_ (at HF frequencies), this should have the same effect as making the entire thing out of copper. I'd be mainly concerned if the Slinky would be as springy with a thin coating of copper ... *73 de AF6AS in **_“DM13”_** land*
Oh MAN that thing is going to be huge and droopy, even if you build it in 2 halves.
I like it, but I think the Mad Dog coil is a better design, more compact and lighter. I would imagine this would cost about the same to make as it would cost to buy a commercial version, such as the Mad Dog, Wolf River, Ten Tec or one of the many Chinese made coils that do the same thing once you assemble and obtain all the parts, I doubt this would be that cheap as an antenna, at least here in Australia. I do like the idea of the full kit inside though and the antenna stowage up the guts of the mount, Very clever design.
I'm not sure you understand the distinction here. This is NOT a "vertical" with a loading coil and ground plane. It's an Off-Center-Fed Vertical DIPOLE. It's just fed about 20% (electrically) from the bottom with a 9:1 UnUn and a CMC. Different animal altogether.
@@rudiwiedemann8173 I am aware one is an OCFD the other is base loaded vertical, but essentially they are the same thing. both offer multiple bands on one wire and have a loaded section to deliver said bands. I know they are a different design, but still, they're doing the same thing.
@@bitemykrank1970they are not the “same thing”. A 1/4 wave vertical needs radials. This is an OCFD. There is no loading. The 9:1 unun is for impedance matching and the choke is to prevent common mode currents on the coax. There is no coil to provide inductance. You would use a coil on the 1:4 wave vertical so it can be used on other frequencies.
Hello...I like your design. I have looked inside several 32 foot vertical HF whip antennas in my time. I was a radio guy in the Navy for the better part of 31 years. So I had the privilege of seeing "deconstructed" vertical whips. The twisted strap approach you opted for is okay but not the way that I have seen commercial grade whips made. It should work though. You also need to drill a small hole in the cap end of that PVC pipe to drain off moisture buildup. Moisture will build up in it. Assuming that the cap is pointed down towards the ground right?
Well no, I didn't design this to Navy Mil Standard specs, Sorry, it's for hams not for warfighting. And you can drain any moisture when you un-cap the top that holds the whip.
@@rudiwiedemann8173 I love your designs! Thanks for posting.
Hi Rudi a very informative presentation. Is it possible to use mix 43 for both a CMC and TLT as I cannot get a mix 31. Thank again for the presentation. Joe.
No. Mix 43 is for Transmission Line Transformers (TLTs) and Mix 31 is for CMCs, because of the magnetic characteristics within the HF spectrum (3-30 MHz)
That’s really cool that it’s all encapsulated like that.
Nice work Rudi! deKK7BUC
What a unique looking antenna (to start with)... but this looks like it would be fun to build and easy to deploy. I'll have to try it (after I learn how to build CMC's and UnUns)!
Watch my TennaTalk #12a and 12b to learn all about it.
Fine business Sir. Innovative. You've succeeded in ariusing my curiosity, now off to build it
Looks interesting indeed! Do you plan a follow up video to show us how you set it up? I'd also like to see how well it performs.
That will be the next video
Remoteley tunable Idea: if you could get a short steel rod with a motor drive near the base you could drive it up and down inside a region of tighter (closer-wound) coil turns to alter the inductance and give it some remote fine-tuning across a band. The motor would turn a threaded rod and and work a bit like a screwdriver antenna. The key thing is to move the steel bolt into and out of a section of tighter coils - in even-spaced coils there will be only marginal change is resonance. Not sure if there are better materials to use(steel is lossy and kills Q) but a steel bolt is cheap and easy to find for an experiment
Each NoodleTenna dipole is a pretty broad-band resonant device in and of itself, so it should not need any tuner or adjustment.
Intriguing design. Thanks for sharing!
That's awesome! I like how you hid everything inside and used a coil counterpoint. EXCELLENT JOB, SIR!
This is NOT a "counterpoise" but simply the lower 20% of the dipole wrapped a few times around the PVC tubing just to hold it and make it short.
Thank you for sharing this with us.KC1TWE.
Very nice! Would an antenna like this work better or worse if it were elevated, instead of on the ground?
Ground-mounted OCFDs are just fine with no real advantage to raise them above ground since there is no groundplane.
It's a type of dipole, so the only thing raising it up off the ground might be to lower the launch angle.
I have never thought of doing a coil for the counterpoise(?) ground plane(?) that is epic! How long of a piece of copper did you use? Or is this more a area thing vs length?
It isn't a "counterpoise" so much as the bottom 20% of a short vertical dipole.
@@antennawhisperer-k7raw151 Ah off center fed vertical then. Got it
I use an 18.5' long, 14 section stainless steel telescopic whip plus 4.5' of 1" wide copper foil tape wrapped around the 2' long tube about 7.5 turns. This is NOT a "counterpoise" but simply the lower 20% of the dipole.
That's amazing, Rudi!!! Can't wait to see the finished product. 73 from W5ODP 😎
I'm posting an update video shortly.