| 摘要 |
PURPOSE:To simplify the structure and to make a printed board in common use by connecting two resonance lines in series and constituting a turning circuit by its combined reactance. CONSTITUTION:One-turn air-core coils 8, 8' are added to a resonance line of a UHF local oscillation circuit. The reactance equal the resonance line of complicated structure is obtained and in case of the lower side superheterodyne system, a resonance line of simple structure the same as that for a conventional system is used to constitute the UHF local oscillation circuit. Then the air-core coils 8, 8' require the selection of size and the adjustment and the minute adjustment of the inductance is attained. Thus, the adjustment of a UHF part requiring the minute adjustment is much facilitated. Further, a variable capacitor diode 2'' is subject to arrangement change between positions A and A', the 2nd resonance line 8'' is opened, and the UHF local oscillation circuit of a conventional system is used and the 1st resonance line and the prined board are used in common.
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