This funky looking item is a Saturn V Instrument Unit directional CCS/PCM Antenna array. The basic structure was fabricated by Metal Research and Mr. Chris Argus of Calumet Fiberglass under subcontract to IBM (NASA Contract NAS 8-1400) and measures approximately 8 X 5 X 23 inches. The antenna cover is made of RF transparent epoxy impregnated fiberglass. The antenna and cover was recovered by a NASA engineer from a Marshall Space Flight Center dumpster after disposal. Because it is likely a test article, it lacks the final white titanium dioxide paint coating which would have been applied after installation on the launch vehicle.
This antenna was a transmit only high gain directional antenna fixed on the IU with the radiation pattern was directed toward the earth by controlling the attitude of the spacecraft. The antenna contained 5 helical elements, 4 in quadrapole arrangement for high gain UHF S-BAND (2282.5 MHZ @ 20 watts) and 1 monopole element. It assumed responsibility for the Omnidirectional antenna pair once the launch vehicle exited their range (approximately 6700 nm above the earth's surface) and provided the Command and Communications System (CCS) downlink and Pulse Code Modulation (PCM)/Frequency Modulated (FM) telemetry signals to ground stations while also acting as a backup tracking transponder. Two antennas were installed for redundancy onboard the Saturn V Instrument Unit in the +Z / Position "I" quadrant.
Thanks to Scott Schneeweis for the technical description of this artifact.