05/08/2026
VINTAGE MILITARY SOLID BRASS ETCHED WORLD WAR 2 ELECTRONICS CIRCUIT DIAGRAM - They certainly don't make them like this any more! This information plate was in with an assortment of donated sheet metal offcuts. On investigation this is a very interesting find originating back to the 1939-45 era in the development of RADAR.
An etched brass diagram like this served as an incredibly durable, industrial-grade manual meant to survive harsh operating conditions without wearing away, tearing, or becoming unreadable from grease, moisture, or heat. It was probably fixed inside a terminal box lid or panel. Technical Details Extracted from the Plate outlines the complete master wiring loom for a complex tracking or rotating station used in artillery target range finding systems, most likely a GL Mk. II Radar Trailer. Notable technical features etched onto the plate include:
• Power Requirements: The system operates on both standard alternating current (230 Volts AC) and dedicated supply lines routed directly through specialized plugs.
• The Magslip Interconnects: On the right, three independent channels ("A", "B", and "E" Magslips) map out the precise circular contact points for the low-speed and high-speed synchro motors.
• Signal Translation: The lower middle section highlights "Signalling Lamps on Transmitter," "Tel. to Transmitter Cabin," and "Tel. to Command Post," confirming that this unit actively bridged communication and directional data between a remote spotting station and a main control hub.
• Inter-component Cabling: The technical specs specify exact vintage cable footprints, such as "Twin 3/.029 C.M.A. T.R.S." (Tough Rubber Sheathed cables standardized by the Cable Makers Association).
Production & Purpose
Historically, these plates were manufactured using photochemical acid etching. A chemical-resistant mask was applied to the brass to outline the blueprint lines, and the plate was submerged in an acid bath (typically ferric chloride) to eat away the exposed metal. The recessed lines were then filled with black or dark enamel paint before the surface was polished smooth.
This exact plate would have been permanently riveted onto an interior bulkhead, control console, or the main distribution box of a World War II-era radar tower, mobile command vehicle, or coastal defence installation.
Size wise its 191mm x 140mm (7.5" x 5.5") with a thickness of 1mm.
We gave it a clean and polish and its now looking for a new home (or maybe a military museum) so it will be on Micks Marketplace shortly.