In a television receiver, a tuning voltage for a varactor tuner is generated by the actuated stage of a plural step neon lamp memory in which each memory stage corresponds to a different television channel. The memory stages are connected as a ring counter which is stepped sequentially by a two-speed oscillator having a fast scan for undesired channel representing stages, and a slow scan to maintain actuation for a short time period of selected memory stages which correspond to desired channels which are to be viewed. Each memory stage includes a potentiometer with a wiper adjusted to generate the tuning voltage. To preprogram the undesired channel representing stages, the potentiometers in the stages are adjusted to produce maximum voltage, which is detected by a threshold switch to cause the oscillator to rapidly step to the next memory stage. A counter detects when all memory stages have been scanned and then disables the oscillator thereby stopping the scanning to maintain selection of the original channel.

The invention relates to broadcast receivers having a voltage controlled tuning device and in particular to a circuit arrangement for applying a voltage to the tuning device. The circuit arrangement is so designed as to be capable of producing tuning voltages to tune the receiver into the desired channels but at the same time being inhibited from producing voltages which tune the receiver into undesired channels such as police channels.

A varactor tuner television receiver touch-tuning system includes a clock pulse-driven counter supplying a binary to decimal converter, which is coupled to an analog switch for sequentially transferring control of the tuner among a plurality of tuning positions. A tuning potentiometer, a position indicator and a position switch are located at each tuning position. Upon closure of any position switch, a transistor switch is enabled to start the counter. The transistor switch is disabled to stop the counter when the selected tuning position is reached.

A radio broadcast receiver is disclosed for sequentially scanning and monitoring a plurality of preselected broadcast channels to determine the presence of a radio signal in any one of the preselected broadcast channels. Selector means are provided for each preselected channel to enable the user to individually select the mode of operation for each preselected channel. Three modes of operation are provided for each channel as follows: (1) the scan mode; (2) the bypass mode; and (3) the select mode. Structurally, the receiver comprises a two pole, three-position switch associated with each channel. With the switches in their "scan" position, the receiver automatically scans each channel in sequence, stopping only on a channel which is broadcasting, and resumes scanning when such station terminates broadcasting. If any switch is moved to a second "bypass" position, the scanning proceeds as above but without stopping on the bypassed channel. The third position, called the "select" position, permits selection of a subgroup of one or more channels to be scanned. A principal advantage of this arrangement is that automatic scanning can be provided between any selected channels by a positive selection process. The user need not work backward to achieve the same result, that is, by bypassing all channels he wished not to scan. In addition, this radio receiver includes a scanning speed control circuit for adjusting the speed of the scanner according to the mode of operation of each channel. Thus, when a preselected channel is encountered with its selector switch positioned in an unused mode, that is either the bypass mode or the non-select mode when another switch is in the select mode, the speed of the scanning is increased to effectively eliminate the scanning period.