Abstract: A standardized chassis for installation of a sound system in an automobile is adapted to receive a component selected from one or more of several groups of components to permit variations in complexity and quality of the composite automotive sound system commensurate with the desires of a user. A face plate, selected from a group of face plates and conforming with the requirements of the components selected, is attachable to the chassis and provides an aesthetically pleasing appearance. The chassis and components include wiring harnesses interconnectable with one or another to eliminate all chassis external leads other than leads for the antenna, electrical power and speakers.

Abstract: A multisegment collapsible self-erecting AM/FM broadcast band power antenna for mobile receiving units includes a tip segment having a restrictor cooperating with a removable collar to limit the antenna extension to an optimum value for the AM/FM broadcast bands. Conversion of the antenna to a length and load impedance commensurate with reception of signals in the AM/FM broadcast bands and transmission/reception in the CB band is effected by replacement of the collar with a loading coil module together with extension of the lower end of the tip segment into the loading coil module and out of physical connection with the adjacent segment. Normal extension and collapse of the antenna remains unaffected and the conversion is reversible.

Abstract: A test unit determines the existence of open or short circuits within the speakers and speaker wire harness of a stereophonic front and rear speaker system in a vehicle. The test unit, having a buzzer incorporated therein, is directly electrically attached to the speaker wire harness through an existing harness plug, which plug includes a lead for supplying electric power from the vehicle battery to the test unit. A rotary switch, mounted upon the test unit and operating in conjunction with a test unit mounted toggle switch, serially tests for both open and short circuits in each speaker and the wire harness leading to and from each speaker. An audible tone emanating from the buzzer and/or a speaker provides an indication of an open or short circuit condition and identifies the location of the fault.