Radio Shack has a regenerative short wave kit that uses a standard ferrite rod as an aerial. The coil consists of 14 turns of aprox. 0.4 mm diameter wire, each turn separated from the next by 0.5mm (to avoid the capacitive proximity effect). I fabricated such a coil by winding two strands of wire at the same time and (after fixing the turns with glue), unwinding 1 wire strand so that the remaining turns are evenly spaced. In a regenerative set of my own design, this tank coil, in combination with a 100 pF variable capacitor allows me to tune from 3 to 7.2 MHz. Sensitivity is really great for 80m. On 40m, regeneration is more difficult to obtain, but even at this frequency, the set is amazingly sensitive. Just to say that dismissing a ferrite rod for use on the shortwave bands altogether doesn't spur with my findings. Great video though!
Regenerative receivers are of course a different kind of beast because they partially make up for the losses in the ferrite rod material. The tradeoff is that the S/N-ratio goes down which is normally acceptable because the background (atmospheric+man-made) noise is much higher than the electronic noise. You should watch my video about "A ferrite rod for SW-reception" where the losses of a special high-frequency ferrite material are explained in more detail with the curves in the detailed datasheet.
Interesting video, I learned a few things. Thanks. (btw, one of the many quirks in English, and forgive me if you know this: Although they are spelt the same, "wound" (for coils) and "wound" (an injury) are pronounced differently. The first sounds more like "wownd", rather than "woond")
Yes, I´ve learned this in the mean time from another comment :-) But part of this video was shot already many months ago before I learned about the right pronounciation of "to wind, wound, wound".
English is about the quirkiest language. Even adults often mis use certain words. (to,too,two -there,their) Benjamin Franklin even suggested removing a few of the letters to reduce redundancies. Another one is lead(the metal) and lead(a wire) Anyone who speaks english is well aware of the quirks and adjusts easily(mostly)
English has no rhyme or reason. It is made of about 5 languages, most Germanic in origin. That's why if someone scolds you about your English, it's usually not an American, because we know it's a messed up language. I wish a language would be created from scratch to be the International language for business and air travel control that is phonetic, easy to understand, and has rules that make sense. The words we have the most trouble with come from the Celtic language, I believe. It's the "ough(t)" words such as through, bough, thought, bought, sought, thorough. Those drive me crazy.
Hello, I see that you have experience in spider-web coils. Please I have a question: - If in the MW band the inductance must be 170 uH and in the LW band the inductance must be 1.9mH..... Can you guide me how much the inductance should be for the VLF band? For example 28 Khz. Thank you so much.
The values I gave you are a 500 pF variable capacitor only. The necessary inductance in combination for any capacitor-value can be calcuted by Thomson´s formula: de.wikipedia.org/wiki/Thomsonsche_Schwingungsgleichung en.wikipedia.org/wiki/LC_circuit#Resonance_effect
It is all about minimising self capacitance. This maximises the tuning range. The coil that looks like a star is the right way to do with this - keep the turns far from each other.
Yes, but much more difficult to wind. The "spider web coils" have low enough self capacitance for tuning the whole AM-range with a 500 pF variable capacitor. More important than the self-capacitance is the lower (external) proximity effect of the star-like coil!
Can you provide some links for the parts necessary to build the antennas? I found out on the internet that some LW coils on ferrite rod antennas have the inductance up to 5 mH, and some MW coils have up to 490 µH. The above stated In the description of „Ferrite Rod Aerial for LW & MW, with link windings on each coil” listing on eBay. Also in the second eBay listing, „Ferrite Rod Aerial Loopstick Antenna with MW and LW Coils 120mm long 3/8" 9.5mm”, in the last (5th) image is stated „Join black and blue to form the ladybird radio «tapping» point.” Does this statement positively influences one of the characteristics of the antenna?
You find most of the answers to your questions in the videos in my playlist "Magnetic Antennas...": ua-cam.com/play/PL6W_lVCKeS04QSwkbsivwqsmZpk8OSM7y.html 1.) The necessary inductance of the reception coil depends on the capacitance of the tuning capacitor. You can do your own calculations in the video series "A Spreadsheet for Magnetic Antennas" included in the above mentioned playlist 2.) You find the necessary parts in our shop (spiderweb-kits, litz-wire, ferrite-rod antennas etc.) 3.) A tapped winding (or a coil with a so-called "coupling winding") is used for receivers with feedback (regenerative receiver) or if you want to transform the high impedance of the tuned tank-circuit to a low input-impedance e.g. of the headphone in a crystal radio set
You can find them in this section in our online-shop: www.ak-modul-bus.de/stat/hf_antennen_und_passive_bauteile.html You can directly order from the shop also with shipping to Australia. When we can fit the ordered parts into a small volume and the weight is not to large, you get much cheaper shipping rates (although slower of course). And of course German VAT is subtracted from the total. So if you order, wait for a manual confirmation from us next day, if we can offer you lower shipping rates.
Put the items you want to buy in the shopping cart. Then click on the "Cart" symbol in the top right with the Union Jack symbol and finish the checkput-process (in English).
Do you know one of Famos b/w Nikola Tesla photos , ... Where .... he sits and behind him there is some kind of similar ""antenna" ? ... circular wire device ... Is that an antenna ... ... or what that might be , ...??? ?
If you mean the connectors for the 2-pin or 3-pin banana-plugs at our spiderweb-coils: They are a part of our spiderweb-coil kits and not available separately.
selbst bei ukw ist das hohe Q durch Litzenanwendung klar feststellbar bei Empfängern , hier wäre es sogar am Besten ,wenn die Spule wie eine Feder gestreckt und gestaucht wird zur freq. einstellung bei kleinsten fix C
Tesla coils are designed only for one certain resonant frequency and their parallel-capacitance is taken into account in the calculation of the resonant freqeuncy. It can be much larger than in applications for radio circuits where you need the lowest possible parallel capacitance.
Very interesting! Liked and subscribed! As a rookie in this field I got a question: As far as I understood, there is a "golden mean" in making AM antennas. So what are the optimal numbers for the best AM reception? The optimal inductance in microHenry? the optimal diameter of the copper wire? The optimal number of coils? The optimal diameter etc.
This is all discussed in the playlist about AM Magnetic Antennas. Especially with the videos about the spreadsheet for calculating the properties and the effects of skin-effect and proxomity effect. The AM range from 550...1700 kHZ is just the "crossover-region" where litz-wire falls behind a thick solid copper-wire at 1 MHz. This can be seen when calculating the properties of our frame-antenna once with litz-wire and once with solid copper-wire of 1...1.5mm diameter. There are simply too many factors to consider to give a recipe for an optimum AM antenna.
They are used in antenna matching and for feedback transformers. I used two stacked with adjustable spacing for a regen set I used in the 1970's. As an auto-transformer you can just add a tap.
What kind of cool could you make that would actually do this effect super large large enough for a person to go through the cold the center of it to create a doorway into another dimension do we rip a door open with magnetic coal into another dimension a place should we transport ourselves through the doorways into the other places around the world are you moving through from one room to another because we possibly do the same to another dimension can we hear sounds from the other dimension or other place in the world like watching a camera in the other room
@@KainkaLabs a piece of "CRAP" that try's to tell people that it's an over unity device, JUST ANOTHER FREE ENERGY WOUNDER OF THE WORLD BULLSHIT DEVISE THAT YOU CAN'T GET COZ ITS ALL VORTEX MATH!!!! WOOOOOOWHIEEEEE!!!!!!!@ OF YEA,,, & THEY MENTION "TESLA" IT WAS HIS IDEA ON HOW THE UNIVERSE WORKED.. SO THE REAL DEAL MANNNN.... THE REAL DEEEEEAAALLLL!!!!
Putting electronic/physics concerns aside for aesthetics..... those air wound coils are fantastic!
Radio Shack has a regenerative short wave kit that uses a standard ferrite rod as an aerial. The coil consists of 14 turns of aprox. 0.4 mm diameter wire, each turn separated from the next by 0.5mm (to avoid the capacitive proximity effect). I fabricated such a coil by winding two strands of wire at the same time and (after fixing the turns with glue), unwinding 1 wire strand so that the remaining turns are evenly spaced. In a regenerative set of my own design, this tank coil, in combination with a 100 pF variable capacitor allows me to tune from 3 to 7.2 MHz. Sensitivity is really great for 80m. On 40m, regeneration is more difficult to obtain, but even at this frequency, the set is amazingly sensitive. Just to say that dismissing a ferrite rod for use on the shortwave bands altogether doesn't spur with my findings. Great video though!
Regenerative receivers are of course a different kind of beast because they partially make up for the losses in the ferrite rod material. The tradeoff is that the S/N-ratio goes down which is normally acceptable because the background (atmospheric+man-made) noise is much higher than the electronic noise.
You should watch my video about "A ferrite rod for SW-reception" where the losses of a special high-frequency ferrite material are explained in more detail with the curves in the detailed datasheet.
Radio Shack is no more :-(
@@chadcastagana9181 I'll be sure to pass that along to the guys at my local Radio Shack in Lewisburg, TN :)
What a great presentation of the information! Thank you!
Glad to hear you discuss the proximity effect. Often overlooked when discussing skin effect.
Interesting video, I learned a few things. Thanks.
(btw, one of the many quirks in English, and forgive me if you know this: Although they are spelt the same, "wound" (for coils) and "wound" (an injury) are pronounced differently. The first sounds more like "wownd", rather than "woond")
Yes, I´ve learned this in the mean time from another comment :-)
But part of this video was shot already many months ago before I learned about the right pronounciation of "to wind, wound, wound".
English is about the quirkiest language. Even adults often mis use certain words. (to,too,two -there,their) Benjamin Franklin even suggested removing a few of the letters to reduce redundancies. Another one is lead(the metal) and lead(a wire) Anyone who speaks english is well aware of the quirks and adjusts easily(mostly)
lochinvar00465 having to homeschool a child.. he Looks at me with this look... we laugh! English is pretty bad. Inverted I hear...
English has no rhyme or reason. It is made of about 5 languages, most Germanic in origin. That's why if someone scolds you about your English, it's usually not an American, because we know it's a messed up language. I wish a language would be created from scratch to be the International language for business and air travel control that is phonetic, easy to understand, and has rules that make sense. The words we have the most trouble with come from the Celtic language, I believe. It's the "ough(t)" words such as through, bough, thought, bought, sought, thorough. Those drive me crazy.
Hello, I see that you have experience in spider-web coils.
Please I have a question:
- If in the MW band the inductance must be 170 uH and in the LW band the inductance must be 1.9mH..... Can you guide me how much the inductance should be for the VLF band? For example 28 Khz.
Thank you so much.
The values I gave you are a 500 pF variable capacitor only. The necessary inductance in combination for any capacitor-value can be calcuted by Thomson´s formula:
de.wikipedia.org/wiki/Thomsonsche_Schwingungsgleichung
en.wikipedia.org/wiki/LC_circuit#Resonance_effect
Good video, but I came for the coil wind in the thumbnail.
The Honeycomb or Duolateral coil! Yes---me too.
It is all about minimising self capacitance. This maximises the tuning range. The coil that looks like a star is the right way to do with this - keep the turns far from each other.
Yes, but much more difficult to wind. The "spider web coils" have low enough self capacitance for tuning the whole AM-range with a 500 pF variable capacitor. More important than the self-capacitance is the lower (external) proximity effect of the star-like coil!
very good vidéo about coils .. thank you
What is that weird buzzing sound
Can you provide some links for the parts necessary to build the antennas?
I found out on the internet that some LW coils on ferrite rod antennas have the inductance up to 5 mH, and some MW coils have up to 490 µH.
The above stated In the description of „Ferrite Rod Aerial for LW & MW, with link windings on each coil” listing on eBay.
Also in the second eBay listing, „Ferrite Rod Aerial Loopstick Antenna with MW and LW Coils 120mm long 3/8" 9.5mm”, in the last (5th) image is stated „Join black and blue to form the ladybird radio «tapping» point.” Does this statement positively influences one of the characteristics of the antenna?
You find most of the answers to your questions in the videos in my playlist "Magnetic Antennas...":
ua-cam.com/play/PL6W_lVCKeS04QSwkbsivwqsmZpk8OSM7y.html
1.) The necessary inductance of the reception coil depends on the capacitance of the tuning capacitor.
You can do your own calculations in the video series "A Spreadsheet for Magnetic Antennas" included in the above mentioned playlist
2.) You find the necessary parts in our shop (spiderweb-kits, litz-wire, ferrite-rod antennas etc.)
3.) A tapped winding (or a coil with a so-called "coupling winding") is used for receivers with feedback (regenerative receiver)
or if you want to transform the high impedance of the tuned tank-circuit to a low input-impedance e.g. of the headphone in a crystal radio set
from australia,, price for themplate to wind coil where to send money..many thanks joe
You can find them in this section in our online-shop:
www.ak-modul-bus.de/stat/hf_antennen_und_passive_bauteile.html
You can directly order from the shop also with shipping to Australia.
When we can fit the ordered parts into a small volume and the weight is not to large, you get much cheaper shipping rates (although slower of course). And of course German VAT is subtracted from the total. So if you order, wait for a manual confirmation from us next day, if we can offer you lower shipping rates.
I went to your shop to purchase some items but I don't speak German. How do I translate to English to place an order?
Put the items you want to buy in the shopping cart. Then click on the "Cart" symbol in the top right with the Union Jack symbol and finish the checkput-process (in English).
Do you know one of
Famos b/w Nikola Tesla photos , ...
Where
.... he sits and behind him there is some kind of similar ""antenna" ?
... circular wire device ...
Is that an antenna ... ... or what that might be , ...??? ?
Where can I get some of those connectors? Are they available online?
If you mean the connectors for the 2-pin or 3-pin banana-plugs at our spiderweb-coils:
They are a part of our spiderweb-coil kits and not available separately.
Danke für deine unterrichtet.
selbst bei ukw ist das hohe Q durch Litzenanwendung klar feststellbar bei Empfängern , hier wäre es sogar am Besten ,wenn die Spule wie eine Feder gestreckt und gestaucht wird zur freq. einstellung bei kleinsten fix C
Can you transmit on one of these? And if not, what happens if you try to?
Small power (
KainkaLabs challenge accepted! I want to try to make one that can take 100 watts.
Have a video-camera or your smartphone ready to shoot the result the instant you connect your transmitter to the coil :-)
@@WalterMelones Hello, how did it go?
Could you not use tesla's bifillar pancake coil then, It's supposed to present ohmic resistance at resonance from what I understand.
Tesla coils are designed only for one certain resonant frequency and their parallel-capacitance is taken into account in the calculation of the resonant freqeuncy. It can be much larger than in applications for radio circuits where you need the lowest possible parallel capacitance.
Very interesting! Liked and subscribed! As a rookie in this field I got a question: As far as I understood, there is a "golden mean" in making AM antennas. So what are the optimal numbers for the best AM reception? The optimal inductance in microHenry? the optimal diameter of the copper wire? The optimal number of coils? The optimal diameter etc.
This is all discussed in the playlist about AM Magnetic Antennas. Especially with the videos about the spreadsheet for calculating the properties and the effects of skin-effect and proxomity effect.
The AM range from 550...1700 kHZ is just the "crossover-region" where litz-wire falls behind a thick solid copper-wire at 1 MHz.
This can be seen when calculating the properties of our frame-antenna once with litz-wire and once with solid copper-wire of 1...1.5mm diameter. There are simply too many factors to consider to give a recipe for an optimum AM antenna.
@@KainkaLabs Oh, thanks a lot! I'm gonna watch them! I thought that wire diameter had a negligible effect on AM reception, it seems I was wrong.
How would they do to make a transformer?
I don´t quite understand the question.
They are used in antenna matching and for feedback transformers. I used two stacked with adjustable spacing for a regen set I used in the 1970's. As an auto-transformer you can just add a tap.
They did not have ferrite in the 20s
But did have iron power and resins
High frequency pancake Tesla coil?
Multiple coil array do you produce them and crystal radio arrays
What do you mean by "multiple coil array" and "crystal radio arrays"? Do you have a link to an example
Spider web coils look more nice and interesting and vintage.
How about starship/Rodin coils?
What´s that?
All wave reception, have you made a video
What do you mean by "all wave reception"?
What kind of cool could you make that would actually do this effect super large large enough for a person to go through the cold the center of it to create a doorway into another dimension do we rip a door open with magnetic coal into another dimension a place should we transport ourselves through the doorways into the other places around the world are you moving through from one room to another because we possibly do the same to another dimension can we hear sounds from the other dimension or other place in the world like watching a camera in the other room
Germans are so smart
Deutsche leute sind sehr klug
it looks like a Rodin coil!!!
What is a Rodin coil?
@@KainkaLabs a piece of "CRAP" that try's to tell people that it's an over unity device, JUST ANOTHER FREE ENERGY WOUNDER OF THE WORLD BULLSHIT DEVISE THAT YOU CAN'T GET COZ ITS ALL VORTEX MATH!!!! WOOOOOOWHIEEEEE!!!!!!!@ OF YEA,,, & THEY MENTION "TESLA" IT WAS HIS IDEA ON HOW THE UNIVERSE WORKED.. SO THE REAL DEAL MANNNN.... THE REAL DEEEEEAAALLLL!!!!
Answer: because the spiderweb has lower interwinding capacitance and proximity effect. BTW you can skip the first 6 mins of this video.