Quasar Electronics Corporation

Matsushita Electric Company of America

Mutsuo Nakanishi

Hans Schmidt

A potentiometer assembly particularly suited for supplying tuning voltages for all of the bands of signals capable of receipt by a television receiver or the like, includes three segments of resistive material arranged in a circle on a support member. Each of the segments corresponds to a different band of frequencies to which the television receiver may be tuned. Band selection is effected by comparable conductive segments on the support member. In one embodiment, a single wiper is used to sweep all of the resistive segments to supply the desired tuning voltage output. A cam arrangement is used to adjust the detented position of the wiper relative to the support member to effect fine tuning at each position. Other embodiments utilize individually adjustable wipers for each station or detent position of the tuner, with each wiper being preset to effect the fine tuning at the detented position of the potentiometer assembly. The individual contacts or wipers for each position are arranged to overlap comparable resistances on the resistive material, so that the entire range of tuning voltages which appear across the resistive material is available from the outputs of the assembly.

Adjustable potentiometer assembly

A multiband tuner control system, particularly adapted for television receivers, utilizes, a three-band varactor VHF tuner. The bands include low and high band VHF signals and a third band of signals obtained from the UHF signals following a first conversion to a third VHF frequency band. This third band is selectively switched to the tuner under the control of channel selection switches. The channel selection switches also cause the conversion of UHF signals to the VHF band to be effected by mixing the UHF signals with a different fixed frequency local oscillator signal in the first converter for each different decade of channels of the UHF signal. The channel selection switches automatically cause this to happen and also select a proper tuning potentiometer associated with the selected UHF or VHF band directly in accordance with the two-digit channel number. The switching of the bands of the tuner is effected automatically by the channel selection switches, as is the switching between the VHF input signals and the converted UHF signals.

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Villa Park, IL, United States of America

Mutsuo Nakanishi