661: Difference between revisions

661 (view source)

288 bytes added , 26 February 2018

32,959

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 === Indicator ===
 The indicator is a conventional X-Y indicator.
-The total CRT accelerating voltage is 3 kV and the vertical and horizontal amplifiers are
+The total CRT accelerating voltage is 3 kV.
-relatively mild differential amplifiers made of [[6DJ8]] tubes and [[OC170]] germanium bipolar junction transistors.
+The 661 uses a [[T5030]] CRT with P2 [[phosphor]].
+The vertical and horizontal amplifiers are essentially the same,
+each consisting of a two-stage differential amplifier.
+The first differential stage is made of a pair of [[OC170]] germanium PNP bipolar junction transistors
+driven single-endedly with emitters connected directly together (maximum voltage gain).
+The second differential stage is made of a both triodes of a [[6DJ8]] tube with cathodes connected directly together (maximum voltage gain).
 The vertical and horizontal amplifiers have feedback loops around them that determine their gain.
-The 661 uses a [[T5030]] CRT with P2 [[phosphor]].
 === Calibrator ===