Load the waveform from a short audio file (maximum length is 1024 sampleĬalculate the waveform from a formula - see examples in the table below. Įdit the waveform in graphical form (using "single point" or "line" editing The arbitrary waveform is stored in array withġ024 sample points, from where it can be read out in any desired speed (using So these sine waves are 'extremely' clean but this is hardly ever required.Įach of the signal generators -also the AM+FM modulators- can be switched Originating from the sine wave function are at least 150dB below the carrier,
If the option 'use table' is unchecked, sinewaves for the generator areĬalculated using the processor's floating point unit (FPU), causing an additionalĬPU load in the order of 20 percent on a Centrino running at 1.7 GHz clock,Īnd an audio sample rate of 192 kHz. The sinewave table method are at least 90dB below the carrier, so this shouldn't Of spectral purity ("spurious" signals caused by interpolation when using The default, checkbox 'use table' set, requires less CPU power, at the expense Tradeoff between CPU load (caused by calculation of sine waves) and speed. This checkbox can be used to turn a transmitter on and off, if configured Generator produces a linear sweep which is ideally suited to test audio filters, With the frequency modulating waveform set to "sawtooth", the AM and FM can be combined though this hardly XX Hertz") and the waveform of the modulating signal for all "frequency The modulation waveform can be sine, triangle, sawtooth or rectangle.ĭefine modulation frequency, modulation deviation (peak deviation, "plus/minus All three sine generators may share the same AM modulator. 40 dB (or even less, if sine waves etc shall be added to the output).Īffects the frequency range which can be controlled with the three frequencyĭefine modulation frequency, modulation factor for all "amplitude modulated" To avoid clipping, keep the noise generators output level below The output of the sine wave generators can beĬan be used to add "white gaussian noise" to the common output of the signal
Note: If a suitable GPS receiver is connected to the PC All three generatorsĬan be individually controlled. "Level": Set the output amplitude of the generator. Hint: you can also connect the frequency of a generator to a "Frequency Slider": Can also be used to change the frequency rapidly, using "Freq/Hz": You can enter the (center-)frequency of the generator here asĪ decimal number (accurate to fractions of a Hertz). "Waveform": Select sine, rectangle, triangle or sawtooth here. "FM": Activates the frequency modulator for this generator. "AM": Activates the amplitude modulator for this generator. "On": Used to turn one of the sine generators on or off. The following controls exist for every generator. Up to three modulatable sine(+) wave generators can be used in parallel,Įach on a different frequency. It means the generator is actually turned off. If the button is labelled "Turn On" and colored grey, Here are just some of the generator controls: Window, or by clicking on the generator block in the The signal generator's control window can be opened from Spectrum Lab's main It if you connect the signal generator to the sound output and the spectrum In SpecLab with this generator, but you can also test a "real" filter with This is a useful tool for testing filters. The signal generator also has an adjustable noise generator (white noise). The generator can be started from the "View/Windows" Point unit, so you need a fast CPU if you want to generate these tones WHILEĪnalyzing the input. The three sine waves are calculated in real-time using the PC's floating You turn it off (so you can use this generator also for one-tone- and two-tone. Each of these "tones" can be adjusted fromĠ.1 Hz to the half sampling rate in 0.1 Hz steps. Three independent audio frequencies may be generated WHILE the audio input Signals into complex signals, and remove the "negative" frequencies in the With I/Q-output, let the signal run through the Output of the generator can be added to the input of the processing chain,īut also to the output (to test external devices). The test signal generator can be activated either from Spectrum Lab's main Controlling the generator via interpreter commands.Generator phase-locking to GPS or timestamps.Sine, triangle, sawtooth, rectangle, or arbitrary ) Three independent signal generators (waveforms : Signal generator with the following features: Spectrum Lab is more than a simple audio analyzer.