| Splitter or Directional Coupler: |
A device having one input and providing two or more isolated outlets for RF cable runs. |
| Streaking: |
A term used to describe a picture condition in which objects appear to be extended horizontally beyond their normal boundaries. |
| Sub-Low Channels: |
TV channels between 5 MHz and 54 MHz(NTSC). |
| Subcarrier: |
A carrier superimposed on the original carrier. Subcarriers are used in satellite television to carry additional information such as the audio or color. Subcarriers for audio can be from 4.5 Mhz to 8.0 Mhz. The audio is used to modulate a carrier which is to be the subcarrier frequency. The modulated subcarrier is then combined with the video information and possibly other subcarriers to become the information waveform used to modulate the main channel carrier. A satellite receiver demodulates the signal to produce the composite video signal which contains the video information and subcarriers and then the demodulates it again, tuned to the subcarriers, to extract the subcarrier information, in this case the audio. A signal that is transmitted within the bandwidth of a stronger signal. In satellite transmissions a 6.8 MHz audio subcarrier is often used to modulate the C-band carrier. In television, a 3.58 MHz subcarrier modulates the video carrier on each channel. |
| Sync: |
An abbreviation for the words, "synchronization", "synchronizing", etc. Applies to the synchronization signals, or timing pulses, which lock the electron beam of the picture monitors in step, both horizontally and vertically, with the electron beam of the pickup tube. That portion of a composite picture signal which is more negative than the voltage representing the blanking level across the output of the picture line amplifier. The color sync signal (NTSC) is known as the color burst. |
| Synchronizing Pulses: |
Pulses imposed on the composite baseband video signal used to keep the television picture scanning in perfect step with the scanning at the television camera. |
| Tap: |
Any device used to obtain signal voltages from coaxial cable. The earlier forms such as capacitive and transformer taps have been replaced by directional couplers in modern systems. A device that channels a specific amount of energy out of the main distribution system to a secondary outlet. |
| Tearing: |
A term used to describe a picture condition in which groups of horizontal lines are displayed in an irregular manner. |
| Television Channel: |
A band of frequencies wide in the broadcast band and designated either by number or by the extreme lower and upper frequencies. |
| Termination: |
A term used in reference to impedance matching the end of cable runs by installing a non- inductive resistor having the same resistance value as the characteristic impedance value of the cable. |
| Tilt: |
The slope, or change, in cable attenuation or amplifier gain. The uneven attenuation of a broadband signal as it travels through coaxial cable. In general, attenuation increases as signal frequency increases. |
| Trap: |
A selective circuit used to attenuate an undesired frequency band without affecting the desired signals. An electronic device that attenuates a selected band of frequencies in a signal. Also known as a notch filter. |
| UHF (Ultra High Frequency): |
In television a term used to designate channels 14 through 83 (NTSC). The TX Converter operates in this band. Ultrahigh frequencies ranging from 300 to 3,000 MHz. North American TV channels 14 through 83. European TV channels 21 to 69. |
| VHF: |
Very high frequencies in the range from 54 MHz to 216 MHz NTSC TV channels 2 through 13. |
| Video Signal: |
That portion of the transmitted television signal containing the picture information. Video Monitor : A television that accepts unmodulated baseband signals to reproduce a broadcast. |
