Disabling RTL2832 AGC

Francesco Gugliuzza f.gugliuzza at hacklabproject.org
Wed Jul 4 23:45:28 UTC 2012


A couple of days ago I posted on Reddit a small modification to
librtlsdr.c to disable the RTL2832 AGC and internal amplifiers (link
to post: http://www.reddit.com/r/RTLSDR/comments/vunuy/experiments_with_agc/c57sbpx
the correct part is after the EDIT).

Add the following lines of code:

/* disable RF and IF AGC */
uint16_t tmp;
tmp = rtlsdr_demod_read_reg(dev, 1, 0x04, 1);
tmp &= ~0xc0;
rtlsdr_demod_write_reg(dev, 1, 0x04, tmp, 1);

/* disable AGC PGA */
rtlsdr_demod_write_reg(dev, 1, 0xd7, 0x00, 1);

/* disable GI PGA */
rtlsdr_demod_write_reg(dev, 1, 0xe5, 0x00, 1);

just after:

/* disable AGC (en_dagc, bit 0) */
rtlsdr_demod_write_reg(dev, 1, 0x11, 0x00, 1);

Since I don't have adequate tools to test the results, could you
please test it, and if it does work, add the patch to your repository?

Thank you!

-- 
Francesco Gugliuzza
HackLabProject.org Administrator
Linux user #374630
Tel (VoIP geographic number): +39 0921440446
Tel (Libera il VoIP number): 5125320
E-mail: f.gugliuzza at hacklabproject.org




More information about the osmocom-sdr mailing list