This video features a detailed teardown and preliminary analysis of a military-grade low-light TV camera manufactured by Barr and Stroud Ltd., potentially for tank applications. The robustly constructed unit, bearing Thales seals, houses a sensitive Vidicon tube as its imaging element. Key internal components include a complex optical system with a motorized rotating filter, a DDC DC-DC converter, and multiple densely packed electronic boards. The circuitry involves a video amplifier with an observable "bodge," deflection coil drivers for horizontal and vertical scanning, and sophisticated digital control using RS422 communication, PALs, a PLL, and a programmable counter to control timing signals. A significant mechanical discovery is a linear guide and a DC motor assembly, which precisely moves the Vidicon tube for focusing. While the camera's image sensor shows signs of wear, the intricate design and the challenge of reverse engineering its digital communication system are highlighted as central points of interest.
Exploring a Barr and Stroud Military Low-Light TV Camera
0:00 Military-Grade Camera Introduction: The video introduces a robust low-light TV camera by Barr and Stroud Ltd., identified as a military item, possibly for a tank, with Thales seals.
0:48 Initial Opening: The speaker unscrews 22 metric screws, revealing a moisture absorber and the beautifully constructed internal components.
1:32 Core Imaging Technology: The camera utilizes a sensitive Vidicon tube for image capture.
1:45 Motorized Filter System: A small motor drives a rotating filter mechanism, likely allowing for selection of different optical filters.
1:57 Power and Control Electronics: Inside, various electronic boards are present, including a DDC DC-DC converter (notably with serial number 666) and power amplifiers for the deflection coils.
3:01 Robust Design & Obscure Parts: The camera features a "very serious design" with numerous trimmers and shielded PCBs. Some integrated circuits, like the ZNA134, are noted as obscure.
3:54 Image Sensor Condition: Visual inspection suggests the Vidicon tube "has seen better days," indicating potential wear or damage.
4:17 Video Amplifier Board: The first board examined is the video amplifier, featuring an MC1733, an analog switch, an AD827, and an RS422 quad differential receiver, confirming digital communication. A visible "bodge" (post-manufacturing modification) is noted on this board.
5:04 Digital Communication and Clocking: The digital section includes a PLL (CD4046) with crystals (one at 5.125 MHz), and PALs (e.g., 20V10), which are likely involved in clock generation and decoding incoming digital commands.
6:05 Reverse Engineering Challenge: The speaker anticipates complexity in reverse engineering due to the requirement to send specific commands via the digital interface to operate the camera.
6:31 Horizontal and Vertical Frequency Generation: One board contains specific ICs (e.g., ZNA134) responsible for generating the programmable horizontal and vertical frequencies for the Vidicon tube.
7:40 Deflection Coil Driver Board: A second board is dedicated to driving the deflection coils, utilizing two power buffers and a CD4053 to generate sawtooth signals.
8:20 Cathode Amplifier and Blanking: This board also incorporates a cathode amplifier with a MOSFET and a PNP transistor for blanking the Vidicon image.
8:38 Current Flow Detection: The deflection coil drivers include a current detection circuit using current sense resistors, voltage doublers, and JFETs to provide a high-level output when current flows through the coils.
9:45 Precision Focusing Mechanism: A significant discovery is a linear guide and a linear DC motor assembly with a worm screw, designed to precisely move the entire Vidicon image assembly for focusing.