[a / b / c / d / e / f / g / gif / h / hr / k / m / o / p / r / s / t / u / v / vg / vr / w / wg] [i / ic] [r9k / s4s / vip / qa] [cm / hm / lgbt / y] [3 / aco / adv / an / asp / bant / biz / cgl / ck / co / diy / fa / fit / gd / hc / his / int / jp / lit / mlp / mu / n / news / out / po / pol / qst / sci / soc / sp / tg / toy / trv / tv / vp / wsg / wsr / x] [Settings] [Home]
Board
Settings Home
/diy/ - Do It Yourself


Name
Options
Comment
Verification
4chan Pass users can bypass this verification. [Learn More] [Login]
File
  • Please read the Rules and FAQ before posting.
  • There are 19 posters in this thread.

05/04/17New trial board added: /bant/ - International/Random
10/04/16New board for 4chan Pass users: /vip/ - Very Important Posts
06/20/16New 4chan Banner Contest with a chance to win a 4chan Pass! See the contest page for details.
[Hide] [Show All]


Janitor acceptance emails will be sent out over the coming weeks. Make sure to check your spam box!



File: CRYSTAL RADIO.jpg (17 KB, 400x240)
17 KB
17 KB JPG
This is a project I'm really into, as I speculate that different minerals with varied shapes and sizes will achieve many different frequencies [and may be varied consistencies of frequency]. Though I can only speculate as I may be slightly uninformed, sorry about that.

I have shitloads of crystals and many kinds of quartz. I also have slightly magnetic crystals with more boxed, resolved shapes. I truly want to experiment with the many natural shapes of crystals.

Oh and is the cool shapes like this star easy to make up for the radio? Does it compromise anything?

Overall, can crystals work out and how can it work?

Thanks for your time. c:
>>
The "Crystal" in crystal radio refers to the detector diode in the circuit. This diode does not define the tuned frequency of the radio receiver.
You should read up on some radio theory before posting.

https://www.electronics-notes.com/articles/radio/radio-receivers/how-does-crystal-radio-work.php
>>
Only certain crystals can work (eg galena)
The crystal does not determine the frequency in any case. Frequency i determined by electronic components that you cant understand.
You are a silly hippie.
>>
>>1330739
Thanks man, sorry for my dumb shit.

>>1330740
Gotcha, haha. Its not selective hippie ignorance just blatant unknowingness. Thanks heaps.
>>
>Build one with a germanium diode
>Get it working
>Remove diode and experiment with crystals in its place

My grandfather said they sometimes had success with coke as used for blacksmithing forges.
>>
>>1330749
my grandfather saw the guys using razorblades in WW2 as the diodes
>>
>>1330749
This is really interesting, thank you.
>>
>>1330752
my grandfather used the fist of his deceased wife and found it had the correct hardness, as he had speculated from years of experience
>>
>>1330752
Right, the foxhole radio. Doesn't even need a crystal.
>>
>>1330758
The razor blade oxide is the crystal.
>>
I hear some decent diodes can be made with a container full of oxidised copper(?) shavings, and these were preferred over cat's whiskers since you didn't have to adjust them constantly.
>>
Yo dumass. Ya you, OP.

Jewgle foxhole radios. It will blow your mind.
>>
>>1331341
>>1330758
>>1330752
not OP, but damn this shit is really cool.
>>
>>1330735
>>1330735
An effective crystal diode suitable for radio purposes can be fashioned by fermenting an extract from the pineal glands of male adolescent wolverines mixed with an aluminum oxide powder and baked at 2000 degrees until it forms the requisite crystalline structures.
>>
>>1330735
Quartz can be used - just not to rectify. was used to provide reference frequencies in higher quality sets during WW2 and afterwards. Quartz oscillators can still be used to do this, and they do allow you to tune a radio with surprising precision, if you can find the correct cleavage plane, cleave and shear out wafers which you can then slice to fit in between a couple precision plates.

rectifier crystals for AM radio typically involve Galena and a point metal contact to provide a primitive diode to rectify a radio signal.

Depending on what "slightly magnetic" crystals you have, you might actually be able to use those for the namesake "crystal".
>>
>>1330735
>Oh and is the cool shapes like this star easy to make up for the radio? Does it compromise anything?
With that shape ypu will start hearing the devil talm to you over the radio.
And the devil is an Asukafag.
>>
>>1330735
The crystal in a crystal radio a piece of iron pyrite and a needle that form a diode. Quartz timing crystals came much later.
>>
>>1330752
they used carbon from a pencil as the needle against the razor blade. Yes it worked.

>>1330758
They crystal is the graphite from the pencil.

>>1331252
You can make a solar panel with an oxide layer on copper.
>>
>>1335090
>crystal is the graphite from the pencil
Wrong. The pencil was just used instead of a needle, the actual rectifying barrier was the Schottky junction between the needle/pencil and the oxidised razor blade. Since the pencil could be replaced with a needle, we can infer that the needle or graphite acts as the metal and the oxide as the semiconductor crystal in this instance.
>>
>>1330749
The Iron (II,III) Oxide can serve as a crystal.
It's how foxhole radios work.
>>
>>1330749
I wonder if coal coke is amorphous carbon and not graphite, which would explain its semiconductor properties. Amorphous carbon has a negative temperature coefficient, which I think only semiconductors have. Amorphous carbon has to be roasted at high temperatures to turn it into graphite, which Edison had to do to his bamboo filaments to stop them from being susceptible to thermal runaway.
>>
>>1330735
>add JO crystals into radio
>turns on every middle aged man who hears the beautiful music it creates

Sounds fun
>>
File: 1484663015011.jpg (136 KB, 644x632)
136 KB
136 KB JPG
>>1330735
Holy shit guy, get the right crystal in there that lets you talk with aliens, or like goblins from hollow earth , i bet hollow earth goblins might have radio
>>
File: IMG_20180220_072902.jpg (95 KB, 941x417)
95 KB
95 KB JPG
>>1335539




Delete Post: [File Only] Style:
[Disable Mobile View / Use Desktop Site]

[Enable Mobile View / Use Mobile Site]

All trademarks and copyrights on this page are owned by their respective parties. Images uploaded are the responsibility of the Poster. Comments are owned by the Poster.