US1948122A
|
|
Thermionic tube
|
US1996820A
|
|
Base and socket structure for radio tubes
|
US1885125A
|
|
Electrical discharge device
|
US1858676A
|
|
Cathode
|
US1830802A
|
|
Electrical discharge device
|
US1897761A
|
|
Seal for vitreous articles
|
US1845310A
|
|
Thermionic tube
|
US1889449A
|
|
Thermionic tube
|
US1892066A
|
|
Thermionic tube
|
US1806109A
|
|
Amplification of electrical currents
|
US1607547A
|
|
Wire and refractory article and method of making the same
|
US1777571A
|
|
Coil and method of making the same
|
US1814759A
|
|
Cathode structure
|
US1853281A
|
|
Thermionic tube and circuits for the same
|
US1806108A
|
|
Hot cathode device
|
US1761577A
|
|
Method of manufacturing wire and porcelain elements
|
US1615022A
|
|
Method of applying earthen material to metal
|
US1615023A
|
|
Metal and porcelain article and method of manufacturing the same
|
US1759910A
|
|
Circuits for thermionic tubes
|
US1943388A
|
|
Cathode device
|