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A linear high-frequency voltmeter and AM detector
(rectification by sampling the collector currents in a complementary emitter-follower amplifier)
By David Knight.
Download the full document:  push-pull_det.pdf
(version 2.00)Abstract: The final-stage collector current of a push-pull complementary-symmetry amplifier is a half-wave rectified version of the signal being amplified. By biasing the amplifier in class C, and using a large amount of negative feedback, the rectification process can be made almost-perfectly linear. This provides the basis for a high-quality AM detector, or a high-frequency linear AC voltmeter. Both functions can also be realised simultaneously, with different time-constants, because there are two collectors from which signals can be extracted. Related articles:  Hi-fi
AM detector, by Robert Batey .  AM Pre-emphasis standards (NAB) USA. Hi Q notch filter (NS LB-5 1969) Ultrasonic receiver . Racal
RA17 C18 . RA17
adapter, part 2 (demodulators). |
© D.W. Knight. 2015
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