Patent GB-1198098-A (GB)
Title: Multi-Band Radio Frequency Tuner-Amplifier
IPC: H01H19/58
Filed: 1967-10-04
Abstract: 1,198,098. Rotary switches; circuit assemblies. GENERAL DYNAMICS CORP. 4 Oct., 1967 [4 Oct., 1966], No. 45318/67. Headings H1N and H1R. [Also in Divisions H3 and H4] A multi-band radio frequency tuner comprises active circuit elements and associated contacts located on a rotor printed circuitboard 40, 42, 44, 46, 48, 50, 52, 54, 56 and 58 and passive tuned circuits and associated contacts on a stator printed circuit-board 12, 14, 16 whereby the active circuit elements may be associated with any one of the tuned circuits to form an amplifier or oscillator circuit. The tuner may be a R.F. amplifier for a radio receiver consisting of a transistor amplifier stage Q1 (Fig. 12) having the transistor Qlr 1  mounted on the rotor printed circuit-board 40, 42 feeding a further similar transistor amplifier stage (Qlr 2 , Fig. 13, not shown), mounted on the rotor printed circuit-boards 44, 46. A further similar pair of transistor amplifiers can be mounted on the rotor printed circuit-boards 48, 50 and 52, 54, and variable capacitance diodes CR1s (CR2s) at the input and output of each RF amplifier can be biased so that either the R.F. amplifier associated with the printed circuit-boards 12, 40, 42, 44, 46, or with 14, 48, 50, 54, 54 are selected separately. The tuned circuits 300, 302, 306 and 308 and (310, 312, 316 and 318) associated with these R.F. amplifiers are mounted on the printed circuitboards 12, 14 and co-operate with the active elements, e.g. transistors and voltage variable capacitors CRlr, CR2r and CR5r, CR6r mounted on the rotary printed circuit-boards 40, 42, 44, 46 via contacts 97 secured to the rotary boards. The voltage variable capacitors tune the amplifiers by a tuning voltage applied at 112 and an AGC voltage is applied via line 102. An oscillator circuit may be provided by the printed circuit-board 16 on which tank circuits are mounted for co-operation via contacts 97 with variable capacitor diodes and transistors mounted on the rotary printed circuit-boards 56 and 58. The wavebands are selected by rotation of spindles 91, 98 which are shaped so as to be keyed to the rotary boards 44, 46, 58 and 48, 50, 56 respectively. The printed circuit-boards 52, 54 and 40, 42 are free to rotate on their respective shafts 91 and 98 but are coupled via nylon gearing 90 <o the other rotary circuit-boards 48, 50 and 44, 46. The spindles 91, 98 may be manually operated directly or coupled to a step gearing unit. The printed circuit-boards may be of multilayer construction and in the case of the rotary boards, e.g. 52, 54, electrical connections between these boards can be made via bolts 70 68 which secure these boards together. The board 12 may have four layers (Fig. 10, not shown) with electrical connection made by conductive holes (32) between the layers. Details of the printed circuits of this layer construction are given (Figs. 5-9, not shown). A connector (99), (Fig. 5, not shown) may be provided on the printed circuit-board 12 for supplying power, input, output, and tuning voltages. The R.F. amplifier may form an exciter fed via a translator.