The Scientific-Atlanta 4647 IF Noise Test Set is designed to be inserted in the 70 MHz IF section of a digital or FM radio, where it will add calibrated levels of white noise. By this means, it facilitates measurement of noise dependent parameters such as FM S/N and bit error rate. A built-in power meter and microprocessor control enable constant carrier-to-noise ratios to be maintained at the 4647 output, regardless of variations in input carrier power caused by fades, path reflections, etc. An additional internal fast AGC amplifier allows for rapid fades (up to 100 dB/sec) over a nominal 12 dB range of input levels and may be employed or bypassed as required.
The Scientific-Atlanta 4647 also contains a calibrated 0 dBm 70 MHz crystal reference oscillator for use in AGC curve measurements and as a general purpose reference source.
Scientific Atlanta 4647 Features
- Automatic calibration of carrier-to-noise spectral density
- IF power measurements from -30 to +10 dBm
- 70 MHz crystal reference source
- Flat noise distribution over 50 to 90 MHz
- Easy operation
- Internal AGC Amplifier to allow for fast input level variation
Scientific Atlanta 4647 Applications
- Simplifies bit-error-rate threshold tests
- Enables clock phase adjustments
- Simplifies AGC curve measurements
- Simplifies FM threshold measurements