“I wrote a octave wrapper around the rtl-sdr library of osmocon. With a little change, to also export the rtlsdr_i2c_read/write_reg function as well as the rtlsdr_set_i2c_repeater function. I then let the standard library do its normal work and just before measuring, I overwrite the E4K_REG_BIAS, E4K_REG_SYNTH1 and E4K_REG_FILT1 registers to their appropriate settings.
Raw data is available. The image itself is pretty raw. The only modifications are a shift of 3 dB below 350 MHz, to compensate the loss due to for 3-phase mixing. and a moving average of 10 samples, to smoothen the curve a little.” — kirepudsje
Source: Reddit Post