AN/VRC-12, 43-49 series radio set siliconization product improvement program

Obsolete germanium devices in the AN/VRC-12 series radios were replaced with silicon devices. A significant reduction in types of transistors used was realized. Three vital modules were completely redesigned to eliminate areas of functional deficiency. Those modules are the A2000A Crystal Switch Assembly, the A5200A/A5300A Squelch System and the A9000A/A9400B Power Supply Assembly. Improved performance and higher reliability resulted from the Product Improvement Program. The siliconized modules are completely compatible with the germanium modules except that the A5200A/A5300A and the A9000A/A9400B must be interchanged as single units.