The General Electric TD256  (P/N 152-0225-00,152-0226-00) is a 100 mA germanium tunnel diode.

Type	 	Ip		Iv,max		Cmax	Vp		Vfs		Vf		Rs(typ)	tr	 	 	 	 
 	 	(mA)		(mA)		(pF)	(mV)						(ohms)	(ps)	 	 	 	 
TD256	 	100 ±10%	17.5		35	150 typ		530 typ		650 typ		1.1	57	 	 	 	 
TD256A	 	100 ±10%	17.5		6	180 typ		500 min		660 typ		1.2	22

Used in

Some instruments using part TD256

Instrument Manufacturer Class Model Description Introduced
146 Tektronix Audio/Video 146 NTSC signal generator 1971

Pictures