The Type NS-1 Noise Source provides a flat noise source power spectrum from about 50kHz to 20MHz (-3dB points) and is intended to be used as an additive noise source along with the Type NCD-1 Non-coherent, the Type CD-1 Integrate & Dump Coherent and the Type COS-1 Costas/squaring loop demodulators in the study of recovered, demodulated data bit errors in the presence of noise. The number of bit errors and thus the Bit Error Ratio (BER) is therefore a function of the demodulation SNR and is set by the noise power delivered by the Type NS-1 Noise Source.
The Type NS-1 allows a selection of either a "wide" (to 20MHz) or "narrow" (to 5MHz Equivalent Noise Bandwidth, ENB) noise output. The total output noise power level is continuously variable or selectable in discrete steps via an 8-position DIP switch.
The Type NS-1 Noise Source also provides a pre-set, calibrated, total noise output power selection of either 2.5mW (+4dBm) or 32mW (+15 dBm) "wide" (28MHz ENB) and 2.5mW (+4dBm) or 10mW (+10dBm) "narrow" (5MHz ENB). This pre-calibrated total noise power output setting is beneficial if an accurate noise power measurement device is not available. Once selected, an on-board six-step selectable attenuator can be used to reduce the noise power from 0-dB to 31-dB in 1-dB steps. All demodulator Types NCD-1, CD-1 and COS-1 require 2.5mW input total noise power to set SNR = 0-dB. NOTE: by "white", it is meant that the noise power spectrum is flat well beyond the operational bandwidth of the input modulation. The total "wide" noise power is the power of the noise measured in a bandwidth > 28MHz into a 50-ohm resistive load.
The Noise Source has the capability to produce non-white total noise power up to the 50mW level (+17dBm) utilizing a selectable on-board zener noise reference. The Type NS-1 operates from a +/-12 VDC @ 250mA, maximum, power source and is polarity protected.
The Type NS-1 Noise Source provides:
- Adjustable total noise output power from 2.5 ~ 32mW (0.353 ~ 1.265Vrms) (28MHz ENB) into 50-ohms, no zener
- Adjustable total noise output power from 0.5 ~ 10mW (0.158 ~ 0.707Vrms)(5MHz ENB) into 50-ohms, no zener
- Adjustable total noise output power from 10 ~ 50mW (0.707 ~ 1.581Vrms) into 50-ohms, with zener
- Reference, calibrated total noise power at 2.5 or 32mW (+/- 1-dB) (28MHz ENB), no zener (Power spectral density, No = 8.93 E-11 W/Hz or 1.14E-9 W/Hz)
- Reference, calibrated total noise power at 2.5 or 10mW (+/- 1-dB) (5MHz ENB), no zener (Power spectral density, No = 5E-10 W/Hz or 2E-9 W/Hz)
- Six-stage resistive pi-type attenuator from 0 ~ 31dB in 1-dB steps arranged as 10, 10, 5, 3, 2, 1-dB
- Noise output level continuously adjustable or in steps, selectable
- Selectable "wide" (BYPASS) or "narrow" (5MHz ENB) on-board lowpass filter
- Requires +/- 12VDC @ 250mA, maximum
Each Type NS-1 Noise Source board comes with:
- Technical Manual that covers Configuration, Operation, General Theory, Application Examples, Block Diagrams, Schematic Diagrams. 50 pages, 36 Figures, 10 Tables, Parts List
- Reference noise power level settings
- One, 3-foot RG-58/BNC 50-ohm cable
- Two, +12VDC wall-mount power adaptors (or use your own +/- 12VDC power supply)
- Five, 2-pin configuration jumpers.
- Type NS-1 board outline (width x depth) is 7" x 6" (177.8 x 152.4mm)