Abstract: Radio transceivers are provided with a timing circuit that ends or terminates a radio transmission after a first time period, and an audible indication signals the end of the first time period. A battery voltage sensor reduces the period of the timing circuit in response to low battery voltage. Shorter period transmissions are still permitted for emergencies, and an audible indication is provided after the short time period to indicate low battery voltage.

Abstract: A battery charger for a portable radio having a battery pack forming a radio-battery unit and arranged to accommodate various combinations of both radio and battery lengths, the charger being provided with a recess for positioning a radio-battery unit in a selected axial position therein with a plurality of axially spaced sets of charging contacts disposed within the recess, each set being arranged for selective circuit making engagement with charging terminals on the battery pack in accordance with the length of the radio inserted with the charger recess.

Abstract: An easily assembled battery contact arrangement for a radio is formed of mating parts which can be assembled without tools and fitted into a mating receptacle in the radio. This arrangement includes an opening which accepts the terminal of a chargeable battery, and provides electrical connection to an external projection which permits the battery to be charged while the battery is in the radio.

Abstract: A battery is held in and connected to a radio receiver by an arrangement having a hollow cylinder that fits in the receiver, and that holds the battery. The cylinder is held in the receiver by first metallic clips. An associated first spring forms the negative connector to the receiver circuit. A closure cover having a metallic portion fits on one end of the cylinder. When a battery is positioned in the cylinder, the cover connects the negative terminal of the battery through the cylinder to the first metallic clips. A metallic contact is held by second metallic clips in the vicinity of the other end of the cylinder. When a battery is positioned in the cylinder, its positive terminal engages the metallic contact and is connected to the receiver circuit through an associated second spring.

Abstract: A grill for a loudspeaker has a relatively thick metallic plate with a loudspeaker opening and a plurality of T-shaped bars across the opening, and a relatively thin metallic plate with a loudspeaker opening and a plurality of U-shaped bars across the opening. The plates are mounted together so that the U-shaped bars are located between but spaced from the T-shaped bars to provide physical protection to and good acoustic qualities for the loudspeaker. The relatively thick metallic plate provides a good heat sink for electronic equipment.

Abstract: A reliable but releaseable arrangement for fastening a radio housing and a battery housing together is provided by a tongue and groove respectively positioned at one end of the housings, and by a hasp and catch respectively positioned at a second end of the housings. Separating surfaces are provided on the facing surfaces of the two housings between the one end and the second end so that the housings separate on impact and reduce the shock to apparatus in the housings.