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tokens: sets with each set obtained from weighted average over 100 voxels. This yields an RMS of for clean modes in the range k ≃ 0.02–1 h Mpc −1 . The RMS estimate can be further improved by averaging over all the data for a fixed τ (this leaves the mean unchanged for reasons outlined in the foregoing) and then computing the RMS using bootstrapping (e.g. Kolopanis et al. 2019 ). We plot the power spectra for both the XX and YY polarizations in all the figures to emphasize the long-term system stability in a drift scan. Our calibration does not involve a polarized source so both the polarizations are assigned equal weight in the beginning of the scan. Our results show that no significant deviation emerges at the end of the scan. As the H i signal is unpolarized, the power spectra for the two polarizations can be added in quadrature to yield a further improvement in RMS by nearly a factor of . 5.5.1 Comparison with other H <sc>i</sc> power spectrum measurements Our results can be directly compared to PAPER H i power spectra upper limits as it was also a drift scan experiment. PAPER was located in Karoo desert, South Africa at geo-coordinates 30°43′17′′S, 21°25′42′′E. Its 2-m antenna had a primary beam (FWHM) of nearly 50°. PAPER’s 64 antennas were placed in a 8 × 8 pattern. For the final results presented in Kolopanis et al. ( 2019 ), six of the antennas were flagged and only a subset of baselines were used for the power spectrum estimations. This subset consisted of 30-m East–West baselines between adjacent columns and those staggered by one row (see fig. 2 of Kolopanis et al. 2019 ). The system temperature for the observational runs varied between 400 and 800 K in the frequency range. These data sets had a total bandwidth of 10 MHz with a channel width of 493 kHz, centred around six frequencies in the range 120–167 MHz. The power spectrum estimate was based on 135 d of observations, but only the data from 124 d was used for LST binning. The LST spanned the range 00 h 30 m 00 s to 08 h 36 m 00 s . The data sets were initially binned with a time resolution 43 s. After the LST binning, they were further averaged with a top-hat filter in time which yielded a resolution of 938 s. With these instrumental parameters, the PAPER collaboration recently published the analysis of its final data products. Their upper limits on the H i power spectra at z ≃ 8.13 are: Δ 2 ( k ) ≃ (1000 mK) 2 at k = 0.2 h Mpc −1 and (380 mK) 2 at k ≃ 0.32 h Mpc −1 (Kolopanis et al. 2019 ). Our upper limit at a comparable wavenumber and redshift is ≃(1000 mK) 2 , based on nearly 35 h of MWA drift scan data. While a more direct comparison between the performance of MWA and PAPER is harder, this allows us to note the following salient differences between the two interferometers and analysis pipelines: (i) the collecting area of MWA is nearly five times large, (ii) PAPER baselines have a higher level of redundancy (Section 3 ), (iii) the time over which the visibilities are averaged is