Transistors as used in the Spectrum 128Products:
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2N3904 Transistor
- As used in the Spectrum 128 +2 at TR4, TR5, TR7 and often fitted incorrectly at the factory on 128 +2 Issue3 PCBs (the silk screen printed on the PCB is wrong for the transistor used). The means the Composite Video output from the AV connector doesn't work properly. See this page for details.
- In the case of the 128 +2 Issue3 PCB, these 2N3904 transistors need to fitted 180' compared to the silk screen legend. EG: TR4's emitter is supposed to be on the right (feeding a 75 Ohm resistor in the resistor net RN1).
BC548B Transistor
- Used at TR1,TR3 and TR6 in the Spectrum 128+2 (grey model)
BC558B PNP Transistor
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