在广播的早期,“Crystal”接收者因其比较廉价和易于建筑而非常受众。
As a matter of fact a crystal receiver is the most simple form of wireless receiving apparatus and, although having a limited range, is hard to beat from the point of view of purity of reproduction.
A crystal detector consists of the familiar piece of crystal and a wire contact, commonly known as a “cat’s whisker”. The “cat’s whisker” is sometimes omitted, and two crystals are used with very good results. The main defect of a piece of wire as a contact is its instability. Everyone who has used a cat’s whisker for listening knows how often it is necessary to readjust this tiny wire, which will lose its contact at the slightest provocation, even when somebody walks across the room.
两个晶体组合得多稳定,条件是晶体架具有良好的设计。
It was discovered some years ago that, if certain natural minerals are placed in a circuit carrying n electric current, the current will pass in one direction only. If a voltage is applied in such a way as to make the current flow in the reverse direction, the mineral or the “crystal” will offer such a resistance that the resultant current will be negligible.
仅允许电流在一个方向上流动的性质被称为整改因此,晶体因此被称为“整流器”或检测器(“无线”信号)。
对于晶体的整流性质的性质存在巨大的观点,但这种缺乏明确的知识并不能不能为“无线”接收而使用晶体来抑制我们的形式。
Some of the crystals are, so to say, born rectifiers, and will rectify on their own without any additional batteries, but others will do their work best if they have a small polarizing batteryin series。
对于敏锐的实验者来说,晶体为原创研究提供了巨大的领域,因为他们的真实房产非常熟知,并且有一个很好的交易需要清除。
Natural and Commercial Crystals
A Japanese scientist, Mr. Wichi Toricata, in his paper “Commercial Wireless Telegraphy in Japan”, published in the电工在16th1910年9月,给出了下表:
- 一世。Ores quite sensitive with perfect contact
氧化物硫化物
ZinCITE(B)简单的硫化物
金属或素酮钼钼
Cassiterite Galena
Anatase锌爆发物
Arkansite Chalkosite
Pyrolusite Iron pyrites
Wad Pyrrhotine.
复合氧化物复合硫化物
miciach magyagite.
Ilmenite,Iserine,Hystatite Tennantite
Magnetite Enargite
psilomelane schwatzite.
(c)金属组合
lolingite.
Meteorite
Smaltite.
- II。矿石与光接触敏感
(a)硫化物(B)金属组合
简单的硫化物烟灰石
马尔卡酸盐或Kyrosite Domeykite
Covelline Strutterudite
铱星
复合硫化物
塞根石
铜硫化物
Cobaltine
Ullmanite.
凤凰
Sylvanite.
砷硫化物
石墨
砷
Nearly all the ores with good conductivity can be used for rectifying purposes, but some of them require a very slight contact and delicate adjustment, and are not practicable. The action of mineral detectors seems to depend upon the chemical and physical properties of the ores, and also upon the conditions of the contacts, but not upon the crystalline structure and axis of the ores.
W. H. eCcls博士为适合“无线”工作提供以下晶体:
- 一世。小学物质
硅
硼
石墨和金属
碲
砷
- II。天然硫化物
纳纳(硫化铅)
Iron pyrites
Chalcopyrites
凤凰
钼矿
- III.天然氧化物
锌胺
布鲁克星
伊斯坦
Psilomelane
Cuprite
厨师
此外:Smaltine,Chalcocite,Inserite。
There are many commercial combinations, but we shall discuss the most successful ones, actually used by prominent manufacturers in this and other countries.
魔法地毯
Philip R. Cararyy先生在他的书中的“电话没有电线的电话”中,给出了以下组合,最适合“无线”电话,即广播:
Perikon(ZinCITE-CHALCOPYRITE)
Carborundum.-Steel
Zincite-Tellurium.
硅-Steel
钼陶瓷库珀
Galena-Graphite.
他还指出,这些钢酸钢,紫红色和锌碲化合物的组合通常是最稳定的,并且通过振动或大气的扰动最少。
碳焊液 - 钢检测器需要额外的偏振电压约一伏。
The perikon and zincite-tellurium require no batteries.
现在让我们考虑最着名的晶体的属性:
Carborundum.。这是盐,沙子,锯末和可乐在电炉中约为1000华氏度的温度下融合的盐,沙子,锯末和焦炭的产品。在低温下,Carborundum具有非常高的电阻,然而,在热量下迅速降低。有时使用1-25伏的偏振电池。
伽利纳 - 石墨。媒体敏感性的检测器,但对机械振动可靠和不敏感。
Anatase.This is an octahedral crystal of oxide of titanium with the chemical formula TiO2和was found to rectify quite markedly. Anatase gives much larger currents with a small applied voltage than does caborundum, and is therefore a much more sensitive detector.
布鲁克星。这是TiO的另一种水晶形式2(将发现它用作小交替电流的整流器,具有与锐钛矿相同的敏感性。
钼矿。这个矿物质(MOS2)以管状六边形棱镜的形式发生自然,裂解类似于云母的裂缝。片材具有金属光泽,并且可以用木桶易于电镀,使得连接线可以焊接到它们。
硅。硅在其纯净状态高度敏感,但商业硅含有一定量的金属钙,并且由于这种金属通过空气迅速攻击,即氢钙薄膜很快覆盖硅表面,然后实际上所有探测器动作停止。
Perikon。Perikon探测器是氧化锌(ZnO)和铜吡锌(CuFE)的组合2)。它是敏感的两倍,比硅探测器更容易调整。
Chalcopyrite and Zincite. These two crystals, used as a detector, require a polarizing battery, but considerable rectifications may be obtained without it. This combination is desirable for use where adjustments may be frequent, due to vibrations or similar disturbances which may be present as in the case of portable receiving equipment.
Cerusite.(American trade name). Cerusite is a better rectifier than carborundum. No polarizing battery is required.
zincite。锌的红氧化物。ZIZINE和黄铜点接触形成可靠敏感的探测器。
碲-Aluminium. Tellurium-Silicon.These are sensitive detectors with or without polarizing batteries.
The Good Points of a Detector
It is rather a difficult matter to judge the comparative sensitiveness of two detectors because many factors have to be taken into consideration, and the tests carried out under exactly the same conditions, but the following are the general properties which a good crystal detector must possess:
a)它应该是机械强大和结构良好的。这意味着它应该能够保持调整,不容易受到干扰。
b)晶体应该是敏感的,即应该具有良好的整流性能,如果它们的设置正确调整。太大的敏感性是不可取的,因为通常在难度获得令人满意的调整。也可能难以保留敏感调整。
c)应容易调整晶体。如果在调整良好接收的设置时发现任何明显的困难,则是一种独特的缺点,因为如果信号进入并且检测器无法正常运行,则可以以这种方式丢失有价值的时间。
d)晶体应具有自保护特性,以防止自动被烧坏,并且如果收到异常强大的辐射,则会被破坏,例如大气干扰。
通常,晶体上的所有点都不同样敏感,有必要调整最大灵敏度。通过通过来自蜂鸣器的弱本地振荡促进接收装置,可以在接收信号或在实际接收之前进行检测器的调整。
水晶电路
晶体电路非常简单,以下几个例子将使您能够了解如何将晶体集放在一起。(图。80)
晶体电路意味着简单地简单地横跨调谐器的晶体支架和一对电话终端。
在上面的电路中,您会注意到这些电路之间唯一的区别是调谐的方法。
auses a slider coil,b螺纹线圈,c变度计,d与冷凝器平行的线圈,e从实验的角度来看是一个松散耦合的鸟瞰。
在制造商的表格的帮助下,可以容易地选择可变冷凝器和右线圈的值。
The typesa和b除非在纯粹的实验观点中使用,否则不推荐。滑块线圈和触摸电感具有所谓的“死端”效果。这意味着线圈的一部分不被用于接收,并且在“死端”时浪费能量。
测温镜类型非常高效,但优选使用线圈冷凝器调谐器开始,因为它使将该晶体设置成稍后的阀门变成了。请注意,电话应始终连接在晶体之间和地球。
尝试接收的各种晶体,看看您是否可以找到一些新的组合或一些新材料,从已知的晶体提供更好的结果。
关于需要偏振电池的晶体,W. Greenwood,B.Sc。(ENG。),A.M.I.E.E.,A.C.G.I.IN,在他的教科书无线电报和电话 - 大学教程新闻(5S。6D。),给出了以下连接图。(图81)
您会注意到电位计(可变电阻)以提供正面或负势的方式连接。
为什么不立即开始尝试水晶?