Easiest, Most Accurate Set-Up
Within the industry, TSG is universally regarded as the BTSC generator which is easiest to set-up and maintain. Initial set-up requires only an RF spectrum analyzer and sideband analyzer and takes less than 15 minutes. Performance verification additionally needs a wideband aural demodulator and an oscilloscope. This enables independent verification of the entire transmission system--TSG, aural exciter, transmitter and diplexer.
All test and set-up modes are selected from the front panel, including Equivalent/BTSC mode selection; pilot phase; pre-emphasis on/off; audio processing on/off and scope separation 6 dB offset on/off.
Composite level setting is highly critical to optimum BTSC performance and that's why the TSG makes accurate level setting easy with positive reading red and green LEDs. With an accuracy of 0.02 dB and temperature stability from 0 to 50 degrees Celsius, the TSG provides the most accurate level set indication of any BTSC generator.
SAP and PRO Channel Inputs
Routing the SAP -- Second Audio Program -- and PRO channels through the TSG allows you to establish precise mixing levels. The TSG's built-in metering lets you accurately measure the injection level of both the SAP and PRO channel, eliminating the need for an additional monitor.
Digitally Synthesized Stereo Baseband
The TSG employs a modern digital synthesis technique to develop the stereo baseband. This method delivers maximum separation and spectral purity. Because it is digital, no critical internal trim adjustments are needed, thus ensuring long-term stability.
Audio Processing Option
In addition to BTSC noise reduction encoding, full audio processing is optional. This additional audio processing eliminates the need for external stereo compressors and limiters before the TSG. The processing is state-of-the-art and includes noise gating, gain platform and semi-automatic loudness control.
Semi-Automatic Loudness Controller
Our exclusive semi-automatic loudness control is a common sense approach which places control of loudness where it belongs--with a human operator. This design avoids the problem of "dumb" automatic level controls which frequently damage the dynamic range differences so important to dramatic programming.
The TSG allows positive remote control of loudness from the studio or master control, using standard Raise/Lower remote control circuits. Attenuation is in 0.5 dB increments, after audio processing. The Reset Line gradually ramps attenuation to zero -- normal -- for smooth, level control.
TSG has three isolated composite outputs, with a total of five unbalanced outputs available as an option. Other output combinations include two balanced plus one unbalanced and one balanced plus three unbalanced. The TSG may be located as far as 3000 cable feet from each aural exciter. Common mode ground loop rejection is typically 100 dB.
Left and Right or Sum and Difference
Ideally, stereo audio should be carried around the plant in discrete form (Left and Right). However, some television broadcasters prefer Sum and Difference (L+R and L-R). TSG will accept either format at its input terminals. The mode is selected by internal jumpers located on the audio input board.
DC Meter Output and Remote Metering
Fifteen channels of metering are provided as well as a meter selector for remote control. The selection of parameters is made by electronic switching that can be operated from the front panel or by remote control. A buffered 0-5 volt output is provided for remote readings.
All the monitoring functions needed for Multichannel Television Sound operation are built into TSG, including: Peak deviation of total carrier; L+R; Pilot; L-R; SAP and PRO. All readings are available from the front panel as well as by remote control and are "peak and hold" type for accuracy and ease of reading. The TSG meets all FCC requirements as a measurement device.
The TSG's built-in front panel correlation meter and contact closure alarm give warning when out-of-phase audio conditions exist. The phase meter (more correctly called a correlation meter) provides continuous indication of the time relationship between Left and Right channels. An alarm circuit closes external contacts and lights up a front panel indicator if there is a phase reversal. The threshold of the alarm is user adjustable.
MSI has so much confidence in the winning performance of our TSG that we commissioned an independent firm of licensed Professional Engineers to test and certify our performance against the competition. The PE's report clearly proves TSG superior in the all-important separation measurements and in every other important parameter as well. The full report is available from Modulation Sciences.
A second evaluation, done by the engineering laboratory of a major television network, underscored the superior performance of the TSG against the competition. The TSG scored better on Equivalent Mode Separation, BTSC Separation and Pilot Protection; consistently exceeding the minimums set by the FCC's Office of Engineering and Technology. The report concluded that the TSG beat the competition in ease of set-up, test and metering and performance over its rated temperature range.
First Among Those Who Test And Measure
As the consistent winner in objective tests, it's not surprising that the TSG has become the industry's standard of performance and the choice of those who test and measure. The TSG was also chosen by most of the four network O&O stations and by key PBS production center stations. TSG is the BTSC stereo reference source for Sarnoff Labs, Consumer Reports, Scientific Atlanta and many others.