A Ferrite-Rod for SW-Reception
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- Опубликовано: 18 окт 2016
- Can you use a ferrite rod for SW-reception?
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Yes, but you hahe to use the right material and take special precautions for the winding.
Everything explained in detail with demonstrations.
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Smarter now. Thanks for a good explanation and demonstration.
Cut and try for starters. Enjoyed you video, thanks for your time.
An excellent very informative video. Since I'm surrounded by ever increasing "electrical pollution," I was forced to install a second "loopstick" antenna for shortwave. My radio uses a ferrite rod for medium wave and "shortwave 1" (2.3-7 MHz). I made my own loopstick antenna for "shortwave 2" (7-22 MHz). The rod I used appears to be material 61, which has a lower permeability than the AM/shortwave 1 rod and looks more gray. I used an approximately ~7 1/8" (~180 mm) rod, and I was surprised to receive many signals including amateur stations on the 20 meter band. I can hear static all the way to 13 meters but there isn't much broadcast activity there. Sometimes when propagation allows, stations on 41, 31 and 25 meters sound like local medium wave stations. On some occasions even stations on 16 meters sound as if they were local medium wave stations. I use the ferrite rod antennas because they "hear" the magnetic signal instead of the static plagued electrical portion. Using the telescopic (electrical) antenna in my location renders these signals useless.
Waste of time. Just make regular loop or buy one.
@@KandiKlover You are a waste of skin and oxygen. They said it worked very well, so not a waste of time at all.
Stop being a useless drain on humanity.
Sir my tube radio Philips 15RB708/00S in m/w anttina coil not original so please help me for good response
@@KandiKlover Don't be so dismissive. It's not a waste of time in the slightest. It's far more transportable than a loop and less prone to damage in a bag. Also, why buy when you can make one for far less whilst also being able to make sure it's operating at optimum for your own sets? Plus, there's far more self satisfaction and learning involved than just clicking in A*****n or E**y.
Quite good theory about ferrite core antenna. Thanks.
Excellent video!
Interesting rod-antenna notion ..
I remember bk in the early 90's a hitachi am stereo C-QuAM modulator using pure. 9999 silver wire winded at a long ferrite rod made in Japan, but I'm not sure what type of material they used on the ferrite rod antenna..
Thanx for the video.. keep up the good work..
Fred Feldmeier
Dubai UAE..👈😎👍🇦🇪
Thanks very informative
Very usefull.Thanks.
1:00
Thanks for mentioning the the standard inductance values for medium waves 170 micro henry and that for long waves 2.2 mh.
Yes this was the key sentence of presentation!
I just do this with tecsun pl365 and included ferrite on top for 160 and 80m.
Our SW ferrite-rod is of 4B1-material from Ferroxcube. It is no longer available. An excerpt from the old ferroxcube-databook can be downloaded from our shop: www.ak-modul-bus.de/cat/documentation/Ferrit_4B1sw.pdf
61-type material is from Amidon and it could be quite similar to the 4B1-material but Amidon is not as extensive with their published material specifications as Ferroxcube is/was.
I think that the more greyish colour comes from zinc instead of the black mangenese ferrite (nickel-zinc vs. nickel-manganese ferrite).
Basically the more black ferrite has a higher permeability thus allowing for smaller coils/smaller dimensions but it works only in the LW/MW range.
The more greyish material is more universal because the losses are smaller at a given frequency and it can be used for higher frequencies.
But the permeability is smaller and thus the coils need more turns with a given dimension of the ferrite rod.
With a regenerative receiver you of course get partially away with the losses in the ferrite material. At least up to a certain frequency, where the losses become so great that no more reception is possible and the effective permeability and therefore inductance drops too much.
Our eponymous master Burkhard Kainka has even succeeded to receive SW-Stations with a crystal-radio set where the inductance was either a coil on our SW ferrite-rod or a small loop-antenna.
Thank you for the documentation link and your extensive reply! I am a great admirer of your master Burkhard Kainka who inspired me to experiment with simple radios at more than one occasion!
I have a question about the reference loopstick you showed with 3 litz wire windings on it (1 small, 1 large, and then one tiny one in blue wire) : I assume these are there to allow the antenna to cover multiple bands, is it possible to have both (or all 3?) bands active at the same time, or do the unused portions have to be open circuited to allow the proper resonance of the remaining coil?
All my childhood days, I was wondering, why do we have the black stick inside radio.
Very very very good
Roger , thanks for the info and video , i am thinking of making the loopstick antenna for a s w Crystal set i built which tunes from 5 to 10 mhz. Needs tuned half wave dipoles to pickup enough signal to hear the audio ! I am wondering if i build a similar rod antenna like the one described in the video would receive enough signal to work as desired ! So happens the coil i made from #12 copper wire (2in) diameter is 3.3 uH ! Any help or recommendation would be appreciated ! Thanks again ! Jerry K9UT
That it has passed through my mind: for short wave try using appropriate ferrite for short wave, as material 61 or similar 4C65, or the 4B1 = K? or the 43 = 4A11
So what is your question?
In the comment below you can see that the material is Ferroxcube 4B1(similar to Amidon 61)
Excelente !!
Thank you for a very interesting explanation on the subject of ferrite rods. I myself experimented a lot with the kind of ferrite rods normally used in MW/LW receivers and I found that those work very well in a reflex regenerative receiver up to 7 MHz (of course the regeneration has to be increased a lot at this frequency). For 80 and 40m in this receiver I used 14 turns of 0.3mm thick enamelled wire wound on a very thin former (heat resistent label printer ) with a length of ca 3 cm. Is the material you use the same as the so called 61 ferrite? I Always thought 61 was for MW/LW. But I noticed that relatively modern (20 years) receivers no longer have the very black material but use a more greyish variety that supposedly has more nickle in it?.
The receiver I am describing appeared as a construction article in the May 2016 issue of Practical Wireless. It only uses a ferrite rod as an aerial and is capable of receiving amateur stations in the 40 and 80 m band.
Erik, thank you for this and your other videos. I find they are instructive, very well done, clear, concise, and even fun to watch. Thanks again Erik .
Ron
I will be making a replacement ferrite antenna for a AM tube radio ,the ferrite antenna that came with my radio was shattered ,so I bought a ferrite blank and magnetic wire ,and am going to try to copy the original best I can ,my broken antenna didn't use any plastic on it .so I am hopeing when I get it done it will work .anyone I put would be nice.
How i Ican matching this antenna with the imput receiver mean calculate number of coil secondary impedance
Obrigado
Can ferrite antenna.be replace ,The tube radio I bought had a broken one.inside,if they can be replaced ,where would I get a new one.,or at least the ferrite for in.it.help anyone.who has a idea for me.
Trying to better understand the choices for insulating the ferrite rod. You mention that Polypropylene, Teflon, and Cellophane are good options. Is that because they have high dielectric strength? Or low dielectric strength? I was planning on 3D printing some insulating collars using PLA filament for the coils. Is there another filament material that would be better? My application will operate between 400-500kHz.
It are the dielectric losses which manifest in the dissipation factor (not the dielectric strength). Lower is better. You find some comparison data here: en.wikipedia.org/wiki/Film_capacitor
Teflon is best followed by polypropylene/polystyrene. I mentioned cellophane because it is readily available as the transparent material that is used in food packing. About the properties of the plastics used in 3D-priners I don´t know. But I think they are not very good concerning the dissipation factor. 500 kHz is not that crtitical concernnig the losses. Remember that this video was about the SW-Range from 2 MHz...30 MHz
@@KainkaLabs Thank you!
sir can you tell me which radio have a very very big ferrite antina ? please tell me
No.
Hi, Is there a English version of the ak-module-bus website ?
No, but some of the manuals are in German and this channel is also intended to explain some of our products.
That's a great tip and it's something I've always wondered about and didn't know the answer until now. Does it need to be ethanol or will other kinds of alcohol also work? Btw it's denatured alcohol not denaturalized (which means something else entirely).
I would only try it with ethanol. The reaction is well described in chemistry textbooks and I am not so much into chemistry to predict if also works with methanol or isoparopanol. Just 2 more hints: Do not use a kitchen burner as I did in the video. Use e.g. a bit of the alcohol that you later use for the reduction reaction. And for not too thick litz-wire or copper wire: use just your solder-iron set to >350°C and use solder with 3% flux ingredient. The action of the flux + the heat of the tip will usually also remove all residues, oxides, sulfides, enamel or PU coating etc.
@@KainkaLabs Thanks for the great information. Chemistry and I have parted ways since high school and ever since then I generally go out of my way to avoid opening a chemistry textbook - hence I prefer asking others ; )
Initially I thought this only applied to the special enamel (polyurethane?) of Litz wires but, coming to think of it, it's a copper reaction so as long as the wire coating is burnt off it should work for any enameled wire. My only addition to this would be to hold the end of the wire near the length to be tinned with a pair of pliers so as to prevent the heat of soldering tip or flame from damaging the wire coating further down.
I just realized I've posted this comment under the wrong video - which is a shame unless you have the power to move it under the correct one.
I think I will stick to my "wind it and try it" method.
you need less trys if you know some of the effects that affect Q-factor and inductance :-)
Hallo Roger, ich habe hier einen Ferritstab liegen, dessen Materialeigenschaften ich nicht kenne, und würde zumindest gerne zuordnen, ob es sich um MnZn oder NiZn handelt. Die beiden Materiale unterschieden sich ja durch Zehnerpotenzen in ihrem spezifischen Widerstand -- damit müsste ich doch alleine mit einem Ohmmeter schon eine Zuordnung machen können, oder? z.B. hätte der Stab mit 10mm Durchmesser und 200mm Länge etwa 50Ω Widerstand, wenn er aus 3B1-Material wäre (p≈0,2Ωm)...wäre es 4B1, läge R hingegen im MΩ-Bereich...richtig, oder mache ich einen Denkfehler?
Widerstand von Ferrit ist unendlich, da die einzelnen Körner elektrisch isoliert voneinander gesintert werden. Die Farbe (Schwarz oder dunkelgrau) ist ein erster Hinweis. Ansonnsten einfach eine Testwicklung mit z.B. 10 Windungen machen, Induktivität messen, daraus µ rückrechnen und mit einer bekannten Ferritantenne vergleichen.
@@KainkaLabs OK, Testwicklung wäre mein Plan B gewesen -- dachte, ich komme drumrum ;-). Und ja, das mit den isolierten einzelnen Körnern war auch mein Verständnis von Ferrit, bis ich in den Datenblättern über die doch sehr unterschiedlichen (und im Fall von MnZn ja sehr niedrigen) Resistivitätswerte gestolpert bin. Was sagen die dann letztlich aus? Danke schonmal für die "Nachhilfe"!
Hello, can I glue a broken ferrite rod back together ? What glue would you recommend ? I would swap the ferrite rod, but I don't know its properties.
in principle it is possible. About the glue you have to try for yourself. I would start with either superglue or 2-component epoxy glue. You will probably only have a single try :-)
@@KainkaLabs I will use UHU endfest 300.
Should I clamp in together with a C-clamp ?
Your 10mm x 200mm rod would probably work, 3B1 ? for long wave, SW and MV. I don't own fancy gear like a frequency generator or a frequency counter, I can't do adjustments.
Our 200x10mm ferrite-rod is of Russian origin. So no datasheet. But it is useable only for LW/MW. Only our 150x8mm rod is of a special ferrite-material suitable for SW-frequencies.
Used in the GE Superadio. @@KainkaLabs
I really like your explanation
I'm Indonesian, I really like electro, what else about radio TX. rx frekunsu .... about radio and how to work radio am sw. and fm .... very interesting
do you have a radio-related site that I can visit. hope you confirm .... si
My radio-related "site" is my RUclips video series about "Magnetic Antennas and Crystal Radios".
You find them as a playlists in my channel.
Where did you get your ferrite bar from.the ones I could find On eBay two side are flat and two side are,I am four droids inch long bar .I am trying to make a new one for tube radio anyone ?
It´s available in our shop: www.ak-modul-bus.de/cgi-bin/eng/iboshop.cgi?showd280!15,374236454720163,FERRITE-ANTENNA
Ferrite rod alone:www.ak-modul-bus.de/cgi-bin/eng/iboshop.cgi?showd280!15,374236454720163,FS20010
It´s just a matter of finding the right number of turns to get the correct inductance with an unknown ferrite rod. There are so many variables (ferrite material, diameter, length, shape, position of the coil on the rod) that you can only it determine it experimentally.
@@KainkaLabs the old ferrite is in several pieces and the new ferrite bar is a larger size ,I couldn't font the same size ,so I going to wrap the length of the new rod,I ordered bees wax to dip it in 0when I am done the replacement rod has two flat side and two round size so that's kinda of a pain too.
Great tutorial! Though, at 21:04 - that's 8 turns, right? (not 7!)
आदित्य Aditya मेहेंदळे Mehendale - 7.5 rounded to 7
8
@@anotherdave5107 That's not how it works - the leadwires complete the turn to make eight. Half turns do not (cannot) exist.
I had tried to make antennas with carbon rods from zinc batteries. Later I realised that it should be ferrite and not carbon.
Admittedly the carbon rods from batteries really look like ferrite :-)
Is aluminium a useable SW material ? It is often used in VHF coils.
What do you mean by "a useable SW material"? As core for a winding or as wire-material? Anyway Aluminum is certainly not suitable for both at SW-frequencies.
@@KainkaLabs It is used for VHF/UHF coil cores. Thats what i mean. CORES.
Have you tried it for transmission?
Ferrite antennas are only useable for reception! If you try to send a high current through the coil the ferrite will immediately saturate. That´s why LW, MW and SW-Antennas are completely different and never use ferrite material.
👍👍👍
Sir, Is Ferrite antenna better than Telescopic antenna ....................
For LW and MW of course. For SW it depends...
I think the " mark is called a quotation mark....
Can I get this ferrite cheap on ebay? 🤔
Probably not. Even our supplier is totally sold out of these (vintage/NOS) ferrite antennas. But you still get one of the last ferrite rods in our shop and wind your own :-)
But did it work?
Yes, of course. It´s a lot better than the material used for LW/MW ferrite antennas.