When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Item: Original Cold War U.S. Military Aircraft Radar / IFF (Identification Friend or Foe) RF Front-End Cavity Tuner Assembly from the AN/APX-6 Transponder system.
Markings & Nomenclature:
Component Label: Stamped A-403 RF HEAD / RF-29/APX-6
Manufacturer: Packard-Bell Co. (Los Angeles 64, Calif.) / Ta-Mar, Inc. (Culver City, Calif.)
Part / Serial Identifiers: A1061293 / Serial 4111
Security Stamping: Original faint military CONFIDENTIAL factory ink stamp visible on the central brass cavity housing.
Component Stencils: Chassis marked for cavities/sockets V-401, V-402, V-403, C-401, CR-401, F-205, and F-206 (SPARE 1/4 AMP. B+).
Historical & Technical Context:
The AN/APX-6 was the standard L-band airborne IFF radar transponder installed across iconic 1950s and 1960s Cold War front-line aircraft, including the F-86 Sabre, F-100 Super Sabre, F-4 Phantom II, and B-52 Stratofortress. This multi-cavity preselector unit translates and tunes microwave interrogation pulses using precision mechanical drive verniers and resonant coaxial cavity tubes (such as 2C39 / 3CX100A5 ceramic/metal planar triodes).
Features & Mechanical Construction:
Triple silver/gold-plated coaxial microwave cavity resonators with finger-stock contacts and tube chimneys.
Three integrated mechanical drum-counter digital readouts geared directly to front micrometer adjustment shafts.
Heavy machined brass and aluminum construction with external RF coaxial port and spring-retained fuse posts on the underside.
Cosmetics: Remarkable surviving technical surplus condition. Retains original plating with honest age tarnish, warm patina, and light surface marks.
Hardware: Counter gears, lock collars, and thumbscrews are intact and turn smoothly. Ceramic insulators and tube contact fingers are intact.
Testing / Intended Use: Untested. Sold strictly as a historic Cold War military avionics artifact, microwave/RF engineering curiosity, or display piece.
