Bruce,
Perhaps I might amplify/clarify Diana's comments:
The RT-524 (not a 'VRC-524') is a part of a radio set up: either an AN/VRC-46, AN/VRC-47, AN/VRC-48 or AN/VRC-49 (part of the AN/VRC-12 series of medium power FM sets). It is not a complete end-item of equipment.
The Antenna AS-1729/VRC consists of:
the AB-719/VRC base antenna support
MX-6707 antenna matching unit, which incorporates a spring assembly to allow the antenna to bend when it strikes an obstruction
AS-1730/VRC antenna element (the lower rod)
AT-1095/VRC antenna element (the upper rod)
The AN/PRC-77, a low power FM radio, does not utilize this antenna assembly, as it is a manpack radio. When the central part of the AN/PRC-77 (the RT-841/PRC-77) is removed and reconfigured for vehicular use with the mounting base, amplifier etc, it becomes the AN/GRC-160. The AN/GRC-160 does utilise the AS1729/VRC antenna.
The nomenclature mentioned above should be helpful when seeking specific parts to make up an end item of radio equipment.
Mike C