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.

Cut and try for starters. Enjoyed you video, thanks for your time.

Smarter now. Thanks for a good explanation and demonstration.

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..👈😎👍🇦🇪

Quite good theory about ferrite core antenna. Thanks.

Excellent video!

1:00 Thanks for mentioning the the standard inductance values for medium waves 170 micro henry and that for long waves 2.2 mh.

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.

Thanks very informative

Very usefull.Thanks.

I just do this with tecsun pl365 and included ferrite on top for 160 and 80m.

All my childhood days, I was wondering, why do we have the black stick inside radio.

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.

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.

How i Ican matching this antenna with the imput receiver mean calculate number of coil secondary impedance

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.

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

Excelente !!

Very very very good

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?

Obrigado

Hi, Is there a English version of the ak-module-bus website ?

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).

sir can you tell me which radio have a very very big ferrite antina ? please tell 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.

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 ?

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

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.

I had tried to make antennas with carbon rods from zinc batteries. Later I realised that it should be ferrite and not carbon.

I think I will stick to my "wind it and try it" method.

Great tutorial! Though, at 21:04 - that's 8 turns, right? (not 7!)

Have you tried it for transmission?

Is aluminium a useable SW material ? It is often used in VHF coils.

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?

Sir, Is Ferrite antenna better than Telescopic antenna ....................

Can I get this ferrite cheap on ebay? 🤔

👍👍👍

But did it work?

I think the " mark is called a quotation mark....