This is a wonderful video. Thanks for all of your careful attention to detail.
@dm9gp
Жыл бұрын
So nice of you 🎉
@jlog7395
10 ай бұрын
Excellent video and detailed explanation of the circuit. Thank you.
@arpittiwari_15
11 ай бұрын
Nice explanation no one give this type of explanation on KZitem
@MrSeeuu
Жыл бұрын
Great video!!!!
@user-sg1qm6ns4q
Жыл бұрын
Thanks for all
@storieefoto
6 ай бұрын
wowww che video. grazie
@cr8cat794
Жыл бұрын
Excellent.
@matthiaswilhelm9813
12 күн бұрын
Ich habe den Telefunken mit einer Spule und 2 Abgreifern.gutes Teil auf Art galvanischer Trafo,ein Schleifer Antenne,der zweite geht zur Diode abstimmen😂❤
@benrose7534
Жыл бұрын
Really nice job...I can't seem to get any thing right I end up with nothing but tangled wire and a mess
@dm9gp
Жыл бұрын
You can do it!
@benrose7534
Жыл бұрын
@@dm9gp Thank You I was successful ! 25@90 turn coil set up similar to yours for the tuning coil a few capacitors and a tunning capacitor from a 1965 zenith am radio I made a mini amplifier with a small speaker about 75 feet of antenna ..works great ! Pick up lots of stations experimenting with different coils as well . Thank you for the inspection .
@jasonmitchell4025
Жыл бұрын
With the 22Gauge 90turn coil length you measure 90mm, why isn't it around 90 x .6mm ~54mm in length?
@dm9gp
Жыл бұрын
I double checked. 22 gauge = 0.7 mm. 90 turns = 7 cm not 9 cm. With 7cm I get 162 yH instead of 222 yH. The calculation shown in the video would then not be for exactly half the length of the coil but for 1 cm further on. As if the coil were wound more loosely, reducing inductance. To resonate at 1400 kHz with 162 yH we would need 89pF which is way less Capacity than the 365 pF that variable capacitor can provide. But go down no further than 655 kHz with 162 yH and max capacity of 365 pF. Good thing then that I wound two more centimeters of coil for more inductance. It was some time ago, I probably did to be on the safe side. So we are good. Good that you checked though. In sum: 90 turns are almost right on a tube whose diameter is 5 cm. Those are then 7 cm of windings. Go for more windings to catch frequencies below 655 Khz, like 540 kHz. i.e. if you don't want to limit your set to the pre 1923 band's 690 kHz lowest frequency. I imagine the boy scouts were probably using a tube of different size.
@praveens3577
2 жыл бұрын
sir, in schematic diode s orientation .is that wrong?
@brandonlaragirl
Жыл бұрын
I thought the same when I first looked at it I thought it was backwards
@dm9gp
Жыл бұрын
In the original schematic, it is like this. In this radio, there is an AC oscillation in a (LC) tank circuit that is floating. So, the direction of the diode is not critical. If you like, imagine the flow counterclockwise. In this specific radio, the LC circuit is not grounded. The Antenna instead should be grounded.
@Adrian_AdamViolonDiGerma-tm3nq
3 ай бұрын
What's actual frequency range can this crystal radio receive?
@dm9gp
3 ай бұрын
The AM broadcast band in the U.S. Check the description and the comments? The frequency range is discussed there. Also in the video.
@_specialneeds
5 ай бұрын
I bit dry buy fascinating.
@Adrian_AdamViolonDiGerma-tm3nq
4 ай бұрын
Why
@Adrian_AdamViolonDiGerma-tm3nq
3 ай бұрын
Hey, the diameter of the tube?
@dm9gp
3 ай бұрын
5cm
@DXingSlovenija
Жыл бұрын
Where do you guys in Europe buy your crystal earpiece? It seams this is not as common item to get as I hoped Amazon or ebay does have them but the shipping to Europe (to Slovenia) is more expensive then the item itself I also tried Conrad, which usualy has a lot of hobby things (it even has a Germanium diode), but not this earpiece I also tried looking for High Empidence headphones and could not find anything Now, maybe I am not looking for the right term in Europe, where were this things usualy found (used), back in the day? It seams back when this radio books were this earpieces were easly uvailable, but where?
@dm9gp
Жыл бұрын
I ordered from U.S. I had same issue with some auction houses on the Web.
@dm9gp
Жыл бұрын
Be creative, improvise: look around for vintage stuff. If you like check this video, maybe it is not the solution but hopefully it can inspire how to work around? kzitem.info/news/bejne/1oyo1XquZmJ9gIY
@DXingSlovenija
Жыл бұрын
@@dm9gp Yea, improvisation will come as a next step :) (I was thinking maybe this buzzers that conrad is full of (but they are active ones, just feed voltage to them and they will scream, so I would need to destroy them to get the crystal out), or maybe this singing giftcards, that also have crystal speakers in them At first I wanted the radio to have the highest chance of working, and since I dont have any high power transmitter near me, only low powered ones (Murski Val, Radio Koper, Radio Capodistria, MMR) I will have to try it out at night I guess. Radio Romania should probably work on it BTW: did you ever try to pasivly amplify the signal, maybe using a dorbell or audio transformer?
@Adrian_AdamViolonDiGerma-tm3nq
4 ай бұрын
@@DXingSlovenijaTransformator digunakan hanya untuk menyesuaikan impedansi Speaker/earpiece yang diperuntukkan untuk radio kristal tanpa listrik, transformer impedansi ini biasa digunakan untuk speaker yang beresistansi kecil yang akan dipasang pada radio kristal. tapi memasang Transformer impedansi untuk speaker biasa pada radio kristal tanpa listrik agaknya tidak lebih baik daripada menggunakan earpiece kristal yang bisa dipasang di telinga dengan impedansi yang sudah cocok untuk radio kristal dimana earpiece ini sendiri akan lebih audibel daripada speaker ber impedansi kecil menggunakan Transformer dengan volume yang sama. Pada elemen Piezo yang terdapat pada earpiece kristal atau Piezo pickup biasa memiliki keramik Piezo dengan jenis yang sama diatas nya, mulai dari ukuran 20mm biasanya memiliki resistansi 200ohm (impedansi satu juta ohm lebih) dan Kapasitansi 30.000 piko farad, satu hal yang membedakan adalah ketebalan membran nya. Pada earpiece kristal biasa memiliki membran yang amat tipis bahkan anda bisa melipat nya seperti kertas. Bedanya dengan elemen Piezo yang biasa dijual adalah tebal diaphragm metal nya yang kokoh. Jika anda akan membuat earpiece anda sendiri, anda bisa membuat nya dengan speaker telepon tua yang bentuknya menyerupai tabung, menggunakan headset impedansi tinggi dari militer, atau menggunakan cakram Piezo mulai dari ukuran 20mm (ukuran dibawah 20mm akan memiliki fleksibilitas diaphragm yang terlalu kokoh, menyebabkan Trebel yang ekstrim, volume kecil dan frekuensi audiosonik tidak akan terdengar sama sekali). Anda bisa menggunakan Buzzer pasif Piezo sebagai pengganti earpiece nya, tapi saya pribadi memodifikasinya. Tujuannya agar keramik Piezo bisa bergetar dengan lebih efektif dengan membran yang lebih fleksibel, saya menghampelas diaphragm Kuningan nya dengan hampelas secara sangat perlahan (ada bekas bengkokkan sedikit saja pada diaphragm nya, maka dipastikan tempelan keramik Piezo nya pecah). Hingga setipis alumunium foil. Pada sambungan kabel nya pun saya modifikasi. Saya memilih untuk membuat papan terminal nya menempel di luar housing nya, bukan menghubungkan langsung dengan elemen Piezo di dalamnya karena bisa meredam getaran Piezo hasil dari frekuensi listrik beberapa ratus mikrovolt yang menurut saya cukup signifikan. Saya menggunakan kawat tipis 0.1mm yang sudah dibengkokkan membentuk seperti ular sebagai kabel internal yang menghubungkan antara elemen Piezo itu sendiri dengan papan terminal eksternal di dalam housing Buzzer Piezo pasif tadi agar tidak ada sedikitpun sesuatupun yang menekan diaphragm Piezo dan mengurangi efektivitas konversi getaran nya. Edit : amplifikasi output audio pada radio kristal tanpa listrik yang paling simpel adalah merangkai paralel resistor atau kapasitor keramik/Milar dengan earpiece nya. Apapun itu, preferensi anda adalah yang terbaik:)
@angti2580
Жыл бұрын
멋지네-----
@kingshukroy4779
2 жыл бұрын
What is the diameter of the coil former?
@dm9gp
Жыл бұрын
Both coils are on the same tube with a diameter of 5 cm.
@connymilsson6861
7 ай бұрын
5 meter and 15 meter i hope
@matthiaswilhelm9813
12 күн бұрын
Mit Schottkydiode und 4000pF läuft der nachts gut.eine BAT 42 Schottky,Silizium 😂
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