Abstract: A plug-in module for an electronic device includes a header having conductors therein which extend therefrom to form terminals, and a substrate connected to the header and supporting electronic components connected to the conductors. One component has a projecting part which extends through the header and forms a guide to align the module with a socket, to facilitate plug-in of the terminals of the header. The module may be a channel element to control the frequency of a radio device and may include a resonant element, such as a piezo-electric crystal, and a coil for tuning a resonant circuit. The form for the coil may be the projecting part for aligning the module, and also provide access to a core therein for tuning the circuit when the module is plugged into the chassis. The module may include a conducting housing which cooperates with the header to form an enclosed structure. A grounding pin may be provided to establish a ground connection for the circuit on the substrate and for the housing.

Abstract: A small plug-in module includes a combined housing and heat sink, and plug-in terminals cooperating with mating terminals on a chassis. The module includes guiding structure to facilitate insertion of the module on the chassis, which may also form terminals for providing a ground connection to the module. The module includes an electronic circuit with components, at least one of which develops substantial heat, such as a transistor. The components are positioned on a substrate which is mounted in heat conducting relation on the base of the housing. The base and/or sides of the housing are constructed to provide sufficient mass to dissipate the heat developed by the components. The housing-heat sink may have recesses into which spring inserts are placed to resiliently engage pins extending from the chassis to guide the module into position and provide a ground connection thereto. Alternatively, terminal pins can be secured to the heat sink to engage sockets on the chassis.