RCA 40250

The RCA 40250  (P/N 151-0148-00) is a Si-NPN bipolar transistor, a 50 V, 4 A diffused-junction ("hometaxial") power transistor in a TO-66 package.

The 1986 151- RPR lists a 2N4231A under part number 151-0148-00.

It is used as the output pass transistor in the positive and negative regulators of the 015-0073-00, in Type 1S1, and in many other instruments.

When replacing an original 40250 operated as a pass transistor, note that modern parts are epitaxial base and even the slowest are twice as fast − the original part's f_t is about 600 kHz at 1 A. A replacement usually needs to be slow to avoid oscillations. Possible substitutes may be 2N5192 (2 MHz TO-225), MJE3055/MJF3055 (2 MHz TO-220), and BD911 (3 MHz TO-220).

Some instruments using part RCA 40250

Instrument	Manufacturer	Class	Description	Introduced
015-0073-00	Tektronix	Power supply	Accessory Power Supply	1967
067-0502-00	Tektronix	Signal generator	Amplitude Calibrator	(?)
067-0502-01	Tektronix	Signal generator	Amplitude Calibrator	1970
067-0601-00	Tektronix	Audio/Video	TV Test Generator	(?)
1101	Tektronix	Power supply	Accessory power supply	1970
114	Tektronix	Pulse generator	Pulse generator	1965
140	Tektronix	Audio/Video	NTSC signal generator	1969
142	Tektronix	Audio/Video	PAL TV Signal Generator	1970
144	Tektronix	Audio/Video	NTSC signal generator	1971
145	Tektronix	Audio/Video	PAL genlock test signal generator	1973
146	Tektronix	Audio/Video	NTSC signal generator	1971
147	Tektronix	Audio/Video	NTSC signal generator	1971
149	Tektronix	Audio/Video	NTSC signal generator	1973
184	Tektronix	Pulse generator	Time-mark generator	1965
1A4	Tektronix	Plug-in	50 MHz quad input amplifier plugin	1967
1S1	Tektronix	Plug-in	1 GHz sampling system	1965
1S2	Tektronix	Plug-in	Sampling system/TDR	1967
284	Tektronix	Pulse generator	Pulse generator	1967
285	Tektronix	Power supply	Sampling head power suppply	1969
286	Tektronix	Multiplexer	Sampling head multiplexer	1970
3S1	Tektronix	Plug-in	1 GHz sampling plug-in	1967
3S2	Tektronix	Plug-in	Dual-trace sampling plug-in	1967
3S5	Tektronix	Plug-in	Programmable sampling plug-in	1968
3S6	Tektronix	Plug-in	Programmable sampling plug-in	1969
3T5	Tektronix	Plug-in	Programmable sampling sweep plug-in	1969
3T6	Tektronix	Plug-in	Programmable sampling sweep plug-in	1969
4501	Tektronix	Scan converter	Scan converter	1969
4701	Tektronix	Multiplexer	8-channel multiplexer	1971
491	Tektronix	Spectrum Analyzer	40 GHz Spectrum Analyzer	1966
5030	Tektronix	Oscilloscope	1 MHz diff-input dual-beam scope	1969
5031	Tektronix	Oscilloscope	1 MHz diff-input dual-beam storage scope	1969
520A	Tektronix	Audio/Video	NTSC/PAL vectorscope	1973
521	Tektronix	Audio/Video	PAL vectorscope	1970
521A	Tektronix	Audio/Video	PAL vectorscope	1973
522	Tektronix	Audio/Video	PAL-M Vectorscope	1970
522A	Tektronix	Audio/Video	Vectorscope	1973
576	Tektronix	Curve Tracer	Curve tracer	1969
601	Tektronix	Oscilloscope	X-Y Storage Display	1969
602	Tektronix	Oscilloscope	X-Y Display	1969
611	Tektronix	Oscilloscope	11" CRT storage monitor	1967
647A	Tektronix	Oscilloscope	100 MHz scope	1967
650	Tektronix	Audio/Video	NTSC color video monitor	1971
650HR	Tektronix	Audio/Video	NTSC color video monitor	1978
651	Tektronix	Display	PAL color video monitor	1972
651HR	Tektronix	Display	PAL color video monitor	1978
653HR	Tektronix	Audio/Video	SECAM color video monitor
656	Tektronix	Display	SECAM color video monitor	(?)
7503	Tektronix	Oscilloscope	90 MHz non-storage mainframe	1970
7504	Tektronix	Oscilloscope	90 MHz non-storage mainframe	1969
7514	Tektronix	Oscilloscope	90 MHz storage mainframe	1970
7704	Tektronix	Oscilloscope	150 MHz non-storage mainframe	1969
7L12	Tektronix	Plug-in	1.8 GHz Spectrum Analyzer	1971
R116	Tektronix	Pulse generator	Programmable pulse generator	1965
R293	Tektronix	Pulse generator	Programmable pulse generator	1965
RE4012	Tektronix	Terminal	High resolution graphics terminal	1976

Pictures

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