Best/Easiest DIY Crystal Radio - No Batteries, No External Power 2024 (4K)
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- čas přidán 23. 07. 2024
- How to make a DIY crystal radio - no batteries, no external power. Step by step.
No special tools or skills. Most parts can be had from recycled things. The purchased parts run about $3. Good during power failures, when batteries are not available, for prepping, etc.
Depending on your design (coil mostly) it can receive in the AM broadcast band, approximately 535 to 1600 kHz.
See Warnings below.
Crystal Radio-Winding The Coil (ABRIDGED) • Crystal Radio-Winding ...
Crystal Radio Coil Sizing • Crystal Radio Coil Siz...
Mount Ball-Knob Handle On Steel Shaft • Mount Ball-Knob Handle...
Crystal Radio Antenna • Crystal Radio Antenna ...
Crystal Radio 3D Printable Parts • Crystal Radio 3D Print...
My Crystal Radio Does NOT Work (FIXES for common problems) • My Crystal Radio Does ...
This one is loosely based on the Cub Scout / Wolf Scout / Boy Scout crystal radio design.
OPERATION TIPS & TRICKS
- A good antenna is important. Longer is usually better (see antenna warning below), a good ground is next most important.
- With some stations, you can put a finger or 2 or 3 inside the tuner coil to improve reception. Move them around for best reception.
- A finger near the coil can also improve reception. Touching the coil directly usually lowers sound volume, BUT a piece of paper or thin plastic between finger and coil often improves sound / tuning. Move finger around.
- Touching different parts of the radio or getting near them can affect performance.
TOOLS
- Screw driver
- Knife
- Sandpaper (small piece, fine)
- Saw, if you do not have the wood & tube already cut
- Hand drill for screw holes
- (Optional) Soldering iron, solder
MATERIALS
- 1 x Germanium Crystal Diode (1N34A)(bought: Amazon, Digikey, Jameco, Mouser...)
- 1 x Resistor (10k ohm)(bought: ditto)
- 1 x Crystal earphone (can NOT be other type)(bought: Amazon, Jaycar, Jameco?) MUST be like the type in the video. Regular iPod or similar will NOT work.
- 1 x Base 21 x 17.5 cms x 2 cms thick or more (wood scrap)
- 1 x PVC pipe 15 cms long or stiff cardboard tube x 2 inch diameter
- 1 x motorcycle / bicycle spoke, 2mm diameter or brass rod or stainless rod
- Enameled bell wire (can be from old transformer, solenoid, ...) (note: I used 0.91 mm or 19 AWG.)
- Screws, stainless or brass (6 for wire hold downs, 2+ for coil mounting),
- Fahnestock clips (2) (bought: Amazon & electrical shops). OR brass washers (13) (bought, hardware store)
- 3 stainless fender washers for wiper.
- 1 bigger, large head screw for wiper.
- 1 felt washer (chair foot floor protector. Hardware Store)
ANTENNA & GROUND
- Antenna are just a long piece of wire (I use scrap wire from old transformers). The longer the better.
- Try different lengths and orientations (vertical, horizontal)
- A good ground helps. A wire to a ground rod is good. Metal water pipes also work well.
NOTES:
- The resistor is necessary to get the best sound from these "new" crystal earphones. The new ones are piezoelectric and have lots of capacitance. Without the resistor the charge builds up then discharges so you get constant "static" sounds. The resistor bleeds off charge so you get louder, and much clearer sound.
- Also called a foxhole radio.
WARNINGS:
- Never connect radio to any source of power. Not house current, nor batteries, nothing!
- Never use the radio during lightning storms.
- Never run an antenna over or near power lines.
- Disconnect antenna and put lead outside when not in use.
- Never ground to electrical items, plugs or similar.
- If you don't know, don't do it.
INTERESTING LINKS
Air Core: www.circuits.dk/single-layer-a...
OTHER CRYSTAL RADIO VIDEOS
- Connect DC Amplifier to Crystal Radio • Connect DC Audio Ampli...
▬ Contents of this video ▬▬▬▬▬▬▬▬▬▬
00:00 Intro
00:41 Upgrades From The Original
01:32 First The Coil!
03:43 Bases: Wood, Plastic, Hybrid
05:05 Tower
06:24 Marking The Wood Pillow Blocks
08:18 Making Wood Pillow Blocks
17:41 Coil & Tower 3D Printed
17:59 Hybrid Pillow Blocks & Tower
19:39 Coil Mounting: Wood
20:53 Coil Mounting: Wood, Measuring & Marking the Base
24:55 3D Printed Tower Mount
25:43 Wood Tower Mount
26:50 Summary of all to this point
27:13 Electrical Wiring Overview
27:53 Fahnestock Clips
28:49 Brass Washer Connectors
30:10 3D Printed Tower Wiring
33:49 Stripping Insulation From Enameled Wires
35:40 Wiring the brass washer connections
36:10 Wiring summary/testing
36:49 Wood base wiring
41:52 Wood base wiring done/review
42:49 Compare 3D base/Wood base
43:05 Make the wipers
50:15 Mount the wipers
51:26 Wiper, length & Knob
52:12 Sand Coil
54:15 Add last components
57:19 Quick Demo - Věda a technologie
Please Note: CZcams will not let me play more than a second of other people's content, that includes radio sampling.
RELATED CRYSTAL RADIO VIDEOS:
Crystal Radio-Winding The Coil (ABRIDGED) czcams.com/video/q4qHss7fdn0/video.html
Mount Ball-Knob Handle On Steel Shaft czcams.com/video/UnsuUAazDTw/video.html
Crystal Radio Coil Sizing czcams.com/video/ejHk5tFeKHk/video.html
Crystal Radio 3D Printable Parts czcams.com/video/BQNaMuYoeKQ/video.html
My Crystal Radio Does NOT Work (FIXES for common problems) czcams.com/video/kCxQ8iPQx4s/video.html
You can save a lot of time on the pillow blocks by using a hole saw attachment on your drill. For 2” pipe, do 2” hole and cut in half. Very quick work. Thanks for the video!
You've made it simple enough for anybody to build one of these sets following your example.
I hope so. Over the years, many people have left comments telling me how they built one with their father, grandfather, child, or grandchild and how they have such fond memories of its magic. If I can pass that to the next generation, it's worth the effort.
Very cool. Love your wire joining video as well. I show it to my new student groups every semester learning soldering
Always glad to hear it's helping people! Thanks.
Awesome video, loved it. Helpful hint: hold your stainless steal higher up (in the white area) on the alcohol flame and it will heat up faster.
Great video. Thank you. Subscribed.
Thank you! This is a great emergency radio. Easy to build. No maintenance. No power. Sturdy. Long life.
beautiful mechanical work
7:48 if you have a table saw, you can make that arch by angling the intake towards the blade (you have to match the apparent width of the blade at that angle to the R of the arch). To make it work, you clamp two boards either side of the blade to guide the board from which you'll cut this arch and later bits from (explanation time takes waay longer than setup). Makes really clean cuts, just take it slowly and feed into the cut from the left side of the blade, while holding the top of the parent material board with another stick. This is great for when you want to cut multiples of the same. The process can be looked up online and it's termed "cove cutting". Pretty safe as long as you feed it properly (so don't sneeze) and use sacrificial sticks. :)
I wish many times I had a tablesaw, but there's no place for it. 😞
Print your parts separately and the glue them together. 4:46 name plate, just print it with a hole and print the name after and glue it in place. Combined the printing takes longer because of the travel, but if you do this separately, the time drops, because the head only prints the basic shape.
Thanks for sharing
Thanks for watching!
Nice video!
Thank you, thank you very much.
confused some how do I determine the number of turns on the coil. Iv strong up a 200' antenna now I just need to build the radio I got some new old stock diaodes from the 50s
I have a video "Crystal Radio Coil Sizing" that should help.
Great video.. thank you. I wanted to up grade mine from years ago. found 10k ohm resistors, but what Watt should I look for .25, .50, 1, 2? Appreciate it..
You can use a smallish one. Do not use a wire wound resistor!
Thank you Sir.. again, appreciate the videos.
I understand in your previous vid about the wrong earphone. B but can i use a old rotary telephone earpiece for the sound?
I have heard you can, but I have never done it.
Long ago I successfully use the earpiece of the rotary phone using diode directly connecting across the two terminal just to experiment. But the sound was low although audiable. But i see everyone now using small earphone and sound is louder
It looks like it's time to use that angle grinder you mentioned to grind a better chisel edge on that old screwdriver.
I'd probably make it worse. Or end up with it in my gut.
Hello i don't know it i ask you this question or not, I'm building a Crystal Radio just like the first one in the video ( Exsept ) I have a antenna coil So this is my question can i design my radio this way and will its work ok >>>>>> Starting from outside antenna wire ........ in to antenna coil ...... in to small variable capacitor to to adjust ...... in to the tuning cuil..... in to the germain diode...... to the whipper..... out to ground wire.
I'm not sure what you are building. Are you adding a coil antenna to a crystal radio? If so, I've found they don't work well unless you are making a tube/transistor radio. If you are substituting a coil antenna for the crystal radio coil, I have no experience making such a thing.
FYI, when you want to heat the wire, put it at the tip of the flame at the top, which is the hottest part of the flame .. not toward the center ..
If I attached a mini amplifier circuit to the output and connect that to a speaker would it work or not?
Yes, I showed how I did it in this video. czcams.com/video/RW3VhnzgjtA/video.html
@@tsbrownie thanks
How long a wire run do you recommend for an antenna? Iv'e seen 5 feet to 30 feet (10m)
One of mine is 15 m, the other is 9 m. Longer is better. Higher is better, but more dangerous to setup and maintain.
Hi I built one of these crystal radios following your guide. It works great on a short antenna. I will upgrade that. However I noticed when I touch one of the earphone connections and tune to areas that just buzz I get clear audio.
Does this mean I need something to tune the antenna?
If I touch any other part there is no change. I don’t understand why touching the earphone connection would change anything?
Buzzing is usually a sign that you are picking up AC signals from home wiring. You should never use the home wiring as a ground! So if you are doing that, don't! It's dangerous. The next most common thing is your antenna is too close to AC wiring or other sources of interference (motors are bad). These radios operate on very tiny amounts of electricity, so getting your hands or other conductive stuff near the radio/antenna can change things a lot.
@@tsbrownie thank you. I tried ground on my central air vent. that could maybe pickup the furnace electronics / motor and it also was next to a touch activated lamp 😅
But I tried other things (water pipe) and still when I touch the earpiece side, stations get stronger or clearer. I do see your other videos with the variable capacitors maybe I need that!
@@ShnitzlHaus In many ways, the electricity in crystal radios acts like static electricity so touching it or having stuff around it can make a difference. The capacitor on the ground helps selectivity.
@@tsbrownie thank you. I enjoy your videos and learning about these radios. I see you uploaded one now and will watch.
I do have another question. Furthest to the left I get a station 1010. Im interested in trying to get a broadcast on 640 anything I can do to try and reach that station?
Hope you don’t mind these questions. I will search the internet to see if any forums or literature as well.
@ShnitzlHaus It seems your radio will not reach the higher frequencies. If that is true, then it is likely that you have too much inductance or capacitance in your tank circuit. Of course I assume there's a station you can receive up there.
do I need battery for that
so where ground connected is that in the batter hi
No battery. You can search crystal radio and see they have a very, very long history going back over 100 years and in many countries. Since most people back then did not have electricity to their homes, this was the only way they could receive. This is the easiest one to build and the cub scout manuals had this as a project.
how long is the coiled wire please explain

The pipe is 2 inches in diameter, 15 cm long. The wire is 0.91mm (19 gauge). You need enough to make 160 turns. The details are in the description.
how long is the coiled wire please explain
Details are in the description.
Can the tuning rod be made of brass?
Yes, brass is a good choice.
Will zinc screws work instead of brass/stainless?
Zinc will corrode easily, especially in contact with other metals like copper. It will work, but you will lose sound volume over time until it quits.
I built this radio using 28AWG magent wire with 132 turns around a toilet paper tube. I used the website you linked to calculate how many turns I needed to get 531 uH. Right now no sound will come out of the earpiece. My antenna is about 30ft long, strung 5ft of the ground, and my ground connection is a stand alone water spigot pipe, which I sanded to clear off the corrosion. I am also using a 1N34A diode. I checked what AM stations there are in my area with a normal radio and there are only 2 strong ones and several faint ones. Also in the middle of the AM band (700-1000kHz) there are no stations. What frequency range can this crystal radio pick up? I am concerned that maybe my radio can only pick up frequencies in this 700-1000kHz range, or if not it can only pick up faint stations.
I did a video on the most common problems: czcams.com/video/kCxQ8iPQx4s/video.html
There's a known problem with earphones made in Taiwan: czcams.com/video/rKeS6vSOu3k/video.html
There are also fake 1n34a diodes. These will work, but very badly. czcams.com/video/H8XlZ7Mry4M/video.html
I ran the numbers. Given the tube is 25mm in diameter. 132 turns of 28 AWG (0.3211 mm) wire is 42 mm long. The inductance is around 201 uH. Not in the 500+ range. The tube would have to be closer to 4" (50 mm) to be in the 500 uH range.
@@tsbrownie My diode is real (has reverse leakage), however my earpiece was made in Taiwan, but I tested it with another circuit and it works fine. I went through your common problems video but I couldn't find anything. Also my tube diameter is 45mm, not 25mm.
@@CharlesFeazelle If you used a powered source to test the earphone, that won't work as a test. You did not mention the resistor across the earphone.
@@tsbrownie I have a 10k resistor across the earphone. I did use a power source to test the earphone. Is there a way to test it without one?
@CharlesFeazelle I use a radio to test. Since you have an antenna, look at my video about the world's simplest radio. If that won't work, then either the earphone or diode is bad. (I've had a diode that tested ok with a digital meter, but would not work in a radio.) If you have a battery powered amplifier, you could use that to see if you've got sound at the outputs. I've got a video on that too.
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You have to hold the wire higher in the flame.
Its hotter higher up the flame.
I've found that modern coatings are very heat resistant and turn to a brown goo when heated. They don't burn off like the old lacquers.
Sir, what resistor should I pick? 4k ohm?
Between 10k and 40k, whichever works better.
And should I put cap?
@tovarichiwantankista9412 Cap should not be used with piezo earphone.
@@tsbrownie Okay, thanks a lot 👍
@@tsbrownie In my experiment with the 1N5711 diode, I found that 2K worked the best. It would vary a lot depending on the capacitance of the earphone.
This device collecting electricity? Any answer my question and how it works
It operates from the power of the incoming radio waves. It's how most early radios worked. It does "collect" electricity and I have used it to power a clock. czcams.com/video/0WvZC3-mR6Q/video.html
Aká je hodnota Rezistor ? Plese. ❤❤
10k to 40k. All info is in the description.
wheres your speaker?
It's an earphone. It's attached on the right side. You see it when I attach its wires.
Am or fm
AM. FM requires much more electronics.
You need a coping saw.
I think he can cope without a special saw.