Early Radio Components

1) Tickler by Siemens & Halske, c. 1914, model RB 30/4, no. 11069, (grinder), for listening to high-frequency signals by grinding a thin steel wire over a rotating metal disc, rendering electromagnetic waves audible due to the fluctuating electrical resistance between steel wire and disc, spring-drive, very good condition, original sheet metal case replaced by plexiglas to display the technology. - 2) 2 wedge-slit fritters (coherers), AEG, c. 1904, after DRP 116113, easily exchangeable model by Slaby-Arco, evacuated glass tube with metal caps, length 3 in. each. - And: 3) Large coherer with mechanical sensitivity control according to Koepsel and von Boas, c. 1905, glass tube, brass electrodes, coherer powder made of brass filings, length 10 ½ in.

布雷克拍品等级是为了方便竞买人判断拍卖品的成色而设置的。布雷克等级用1到6级来标注外观和功能的成色，(从非常好到非常差)。 在目录图册里用括号里的2个数字来表示，前一个数字表示外观成色的级别，后一个数字表示功能成色的级别。如(3/2)表示外观成色是3(满意的)，功能成色2(好)。 成色 定义参照下列标准： 1 - 非常好 (未使用过，没有使用痕迹) 2 - 好 (新，极少的使用痕迹) 3 - 满意的 (普通的使用痕迹) 4 - 及格的 (明显的使用痕迹，某个非主要部件是后配的) 5 - 有缺陷的 (极明显的使用痕迹, 某个主要部件是后配的，功能上有缺陷，需要修理) 6 - 非常差 (严重破损, 缺少重要部件)