| 摘要 |
In television (TV) receivers, the VHF-TV band including channel 2-13 is perceived by most viewers as being a single TV band even though it is in fact partitioned into lower and upper frequency portions, including channels 2-6 and 7-13, respectively, which are separated by a gap. Voltage controlled tuning systems for such TV receivers employ a tuning voltage which varies over substantially the same range of magnitudes from a lower voltage to a higher voltage for each of the frequency portions of the VHF band. Accordingly, conventional channel indicators responsive to the magnitude of the tuning voltage partition the bands to avoid ambiguity in the channel indication. In the present arrangement, a tuning indicator produces an on-screen bar display having a position which is indicative of the selected channel for all VHF channels as if the VHF frequency band was continuous and not partitioned thereby being consistent with the perception of most viewers. Specifically, the tuning indicator includes a divider device for attenuating the tuning voltage when a channel in the lower or upper VHF band is selected, a device for developing an offsetting voltage when the selected channel is in the upper VHF band, and a device for combining the attenuated tuning voltage and the offsetting voltage to develop a control signal which determines the position of the bar on the TV screen.
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