Patent GB-220161-A (GB)
Title: Improvements relating to wireless receivers
IPC: H05K7/02
Filed: 1923-08-02
Abstract: 220,161. Stockall, Marples, & Co. (1912), Ltd., and Stockall, J. J. Aug. 2,1923. Sets, construction of.-Receiving sets, built up on the unit principle, comprise a foundation panel, which may he employed as a tuning unit or as a complete crystal receiver, and one or more additional panels, fitted with filament rheostats and connector sockets into which interchangeable plugs may be placed for making appropriate connections. For tuned anode amplification and for reaction a third type of panel may be employed. Figs. 1, 2 and 3 show the wiring of the foundation panel, the tuned anode panel, and the additional panels respectively, and Fig. 13 shows an example of a set built up of five panels. Referring to Fig. 1, the coil L connected between the aerial terminal A and earth terminal E is shunted by a tuning condenser C, and eight terminals 4 are provided, four at each side of the panel 1. The upper left-hand pair are for connection to the HT battery and the lower pairs for the filament battery. A four-socket connector 6 similar to a valve-holder, and a twosocket connector 5 are also provided, wired as shown. When the panel 1 is used as a crystal receiver, the detector is plugged into the socket 5, a plug a, Fig. 4, is inserted in the connector 6, and the phones or a low-frequency amplifier are connected to the upper right-hand terminals 4. When valves are employed for high-frequency amplification or detection, the crystat detector is removed from the socket 5, and a plug b, Fig. 5, inserted in the connector 6, the panel 1 serving then merely as a tuning-unit. A panel 3, Fig. 3, is then attached by four straps to the side of the panel 1, as shown in Fig. 13. The panel 3 has eight terminals 4 arranged similarly to the terminals 4 on the foundation panel 1, two foursocket connectors 11, 12 wired as shown, and a filament rheostat 13. A valve is plugged into the connector 12, and a grid condenser and leak 16, Fig. 6, or a plug a, Fig. 4, is inserted in the connector 11, according as the panel 3 is to serve as detector or as high-frequency amplifier. The panel 3 is also adapted to serve as a low-frequency amplifier if a transformer plug 17, Fig. 7, is inserted in the socket 11. The terminals 14 at the top edge of the panel 3 are normally shortcircuited, but a grid-biassing battery may be connected between them. The third type of panel 2, Fig. 2, carries a coil L<1> and a variable condenser C<1> connected to form a tuned circuit, and a coil L", serving for reaction, connected between the terminals 9, 10. Referring to Fig. 13, the foundation panel 1 has a plug b inserted in its upper socket so that this panel serves as an aerial tuner. The next panel 3 has a plug a inserted in its upper socket and a valve V in its lower socket, thus serving as a high-frequency amplifier. The third panel 2 carries the tuned anode circuit L<1>, C<1>, and the fourth panel 3 is arranged as a detector unit by inserting a gridleak plug 16 in its upper socket and a valve V in its lower socket. The fifth panel 3 serves for low-frequency amplification, having a transformer plug 17 inserted in its upper socket. Reaction from the detector output to the tuned anode circuit L<1>, C<1> is effected by connecting in the reaction coil L" by the terminals 9, 10 and leads 7, 8. Other arrangements of the units are described in the Specification.