Description:
The SAP-1 & SAP-2 are designed to encode a monaural audio signal into the standard BTSC format for use as a Second Audio Program channel for television transmission. Typical uses include transmission of second language programming, local radio stations, promotions of pay services, weather reports, and FSK data.
The SAP-1 generator may be used in conjunction with virtually any existing BTSC-compatible mono or stereo TV-audio modulator. The SAP-1 may be used independently or with a BTSC stereo encoder which has an input for a SAP carrier. Two audio inputs are provided on the SAP-1; one for the SAP/A program and another for the MAIN/B program. A separate level control is provided for each input. When used on a mono (not stereo) channel, the main and SAP inputs are processed and combined into a composite multiplex signal which is sent to the TV-audio modulator. When used with stereo the SAP-1 can be configured for two SAP audio inputs, facilitating switch-over from the primary SAP program to an auxiliary input, such as a local commercial insert. The alternate signal is selectable by either a front panel switch or by remote control (contact closure).
The SAP-2 is designed specifically for use with Leaming's MTS-2 series and the MTS-4A series BTSC stereo generators. When used with the MTS-2 series generators or the MTS-4A, the SAP-2 derives it video sync and operating power from its related stereo generator. Two audio inputs can be provided to the SAP generator, facilitating switch-over from the primary SAP program to an auxiliary input, such as a local commercial insert. Individual level controls are provided for each input. The alternate signal is selectable by either a front panel switch or by remote control (contact closure). |
Features:
The New Built-in AGC (Automatic Gain Control) is provided to maintain average program levels within a reasonable range without reducing the dynamic range to the extent that quiet passages are no longer quiet and loud passages are no longer loud. It includes a gated-gain low-distortion compandor with a fast attack and slow release. When the program level falls over 20 dB below normal, the compandor assumes that there is a pause in the program and holds its gain setting for 10 seconds. The compandor then slowly resets its gain to 0 dB. The AGC is enabled by a front panel switch.
Both SAP-1 & SAP-2 are powered by a built-in power supply and is enclosed in an aluminum case which can be mounted on 1/3 of a Leaming PMU413 19-inch panel mount. These panel mounts accommodate up to three units. |
