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Here there is presented BBQ data taken during an SPS instability occurred when one bunch LHC beam was going coast. The data was acquired during collimator MDs on 12/10/04 at 0h39. Below is the link to the 87s WAV file (attention: ca 16MB).

L channel = H plane, R channel = V plane (≈ 16 MB, 87 s, 16 bits, 48 kS/s).

Below are shown the time domain signals.

Fig. 1H. H plane time domain signal.

Fig. 1V. V plane time domain signal.

Samples of the H and V signals, sampled with the frequency of f_s = 48 kHz, were divided into segments N = 19200 long (t = N / f_s = 0.4 s), with offset m = 9600 samples (t = m / f_s = 0.2 s), so each two adjacent sections overlap by 50 %.
Samples of each segment were multiplied by the Hann window prior to calculating their discrete magnitude spectra. The bin spacing of the discrete spectra is Δf = f_s / N = 2.5 Hz.
Since the presented spectra contain many details, for each plain there are shown separately a general overview, the vicinity of the tunes and the lower parts of the spectra with the focus on the synchrotron sidebands.
There are presented contour plots and their cross-sections at the most characteristic moments.

Below are shown H and V contour plots with each spectrum segment normalized separately.

Fig. 2H. H plane magnitude spectra, 3 kHz bandwidth shown, each spectrum segment normalized separately.		Fig. 2V. V plane magnitude spectra, 3 kHz bandwidth shown, each spectrum segment normalized separately.
Fig. 3H. H plane magnitude spectra, 1 kHz bandwidth shown around the tune, each spectrum segment normalized separately.		Fig. 3V. V plane magnitude spectra, 1 kHz bandwidth shown around the tune, each spectrum segment normalized separately.
Fig. 4H. H plane magnitude spectra, low frequency synchrotron sidebands shown in 1 kHz bandwidth, each spectrum segment normalized separately.		Fig. 4V. V plane magnitude spectra, low frequency synchrotron sidebands shown in 1 kHz bandwidth, each spectrum segment normalized separately.

Below are shown H and V contour plots with all spectra normalized to the highest bin from all segments.

Fig. 5H. H plane magnitude spectra, 3 kHz bandwidth shown, all spectra normalized to the highest bin from all segments.		Fig. 5H. H plane magnitude spectra, 3 kHz bandwidth shown, all spectra normalized to the highest bin from all segments.
Fig. 6H. H plane magnitude spectra, 1 kHz bandwidth shown around the tune, all spectra normalized to the highest bin from all segments.		Fig. 6H. H plane magnitude spectra, 1 kHz bandwidth shown around the tune, all spectra normalized to the highest bin from all segments.
Fig. 7H. H plane magnitude spectra, low frequency synchrotron sidebands shown in 1 kHz bandwidth, all spectra normalized to the highest bin from all segments.		Fig. 7V. V plane magnitude spectra, low frequency synchrotron sidebands shown in 1 kHz bandwidth, all spectra normalized to the highest bin from all segments.

Below are shown H and V linear spectra at selected moments with each spectrum segment normalized separately.

Fig. 8H. H plane linear magnitude spectra in 3 kHz bandwidth at the moments specified on the plots, each spectrum normalized separately.		Fig. 8V. V plane linear magnitude spectra in 3 kHz bandwidth at the moments specified on the plots, each spectrum normalized separately.
Fig. 9H. H plane linear magnitude spectra in 1 kHz bandwidth around the tune at the moments specified on the plots, each spectrum normalized separately.		Fig. 9V. V plane linear magnitude spectra in 1 kHz bandwidth around the tune at the moments specified on the plots, each spectrum normalized separately.
Fig. 10H. H plane linear magnitude spectra in 1 kHz bandwidth with the focus on synchrotron sidebands at the moments specified on the plots, each spectrum normalized separately.		Fig. 10V. V plane linear magnitude spectra in 1 kHz bandwidth with the focus on synchrotron sidebands at the moments specified on the plots, each spectrum normalized separately.

H plane log spectra, normalized to the highest bin from all spectrum segments.

Fig. 11H. H plane dB log magnitude spectra in 3 kHz bandwidth at the moments specified on the plots, each spectrum normalized separately.		Fig. 11V. V plane dB log magnitude spectra in 3 kHz bandwidth at the moments specified on the plots, each spectrum normalized separately.
Fig. 12H. H plane dB log magnitude spectra in 1 kHz bandwidth around the tune at the moments specified on the plots, each spectrum normalized separately.		Fig. 12V. V plane dB log magnitude spectra in 1 kHz bandwidth around the tune at the moments specified on the plots, each spectrum normalized separately.
Fig. 13H. H plane log dB magnitude spectra in 1 kHz bandwidth with the focus on synchrotron sidebands at the moments specified on the plots, each spectrum normalized separately.		Fig. 13V. V plane log dB magnitude spectra in 1 kHz bandwidth with the focus on synchrotron sidebands at the moments specified on the plots, each spectrum normalized separately.