Extremely Rare US Navy C-1360/SRT Control-Monitor (Hoffman Laboratories Inc)

The C-1360/SRT Control-Monitor is a rare mid-century U.S. Navy communications device designed to visually monitor and regulate radio frequency signals between 0.3 and 30 MHz. It was part of the AN/SRA-18 antenna tuning group and built by Hoffman Laboratories under Navy contract NXSR-87692. Here’s a deeper look into its background and technical significance: Technical Overview Model & Designation: C-1360/SRT, part of the Joint Electronics Type Designation System (JETDS) Function: Dual-purpose control-monitor—examines RF output and regulates transmitter operation Monitoring Method: Visual, via analog meters and indicators Input Signal Type: Amplitude-modulated radio frequency Frequency Range: 0.3 MHz to 30 MHz Voltage Requirements: AC: 117V at 60 Hz DC: 28V (not always included) Phase: Single-phase operation End Application: AN/SRA-18 antenna tuning group used in naval communications Historical & Collector Context Manufacturer: Hoffman Laboratories Inc., under Navy Department Bureau of Ships Contract Info: NXSR-87692, Order No. 14247-PHILA-52 Era: Early 1950s, likely around 1952 based on contract and inspection markings Use Case: Shipboard or shore-based RF signal monitoring and control, likely tied to high-frequency communications systems Build Style: Ruggedized metal chassis with vacuum tubes, rotary switches, and analog meters—typical of Cold War-era military electronics

Condition

Used (normal wear)