May 2026 - osmocom-sdr - lists.osmocom.org

[PATCH] Add RTL-SDR Blog V4L Support
by Carl Laufer 11 Aug '26

11 Aug '26

Hi all, The RTL-SDR Blog V4 model is based on the R828D chip, which is no longer in production, and the stockpile we were using is now running low. But we found a bunch of stockpiled R828*S *chips, which I intend to use for a "V4 Lite" model that will allow a similar V4-like architecture to continue being sold for at least another year (and hopefully at a slightly lower price, too). To support the R828S chip a driver update is needed. It's a little confusing as the R828S chip presents itself on I2C as an R820T/R860. Like the Blog V4 patch, the code looks for the "RTLSDRBlog" and "V4L" strings in the EEPROM manufacturer/product strings to know what it's dealing with. The R828S also has only two inputs, so there are some switching changes, and hence the 'lite' designation, as it doesn't have the additional VHF/UHF split filtering that we could do with the three inputs on the R828D. I also added a small mod to disable the tracking filter when in HF upconversion mode for both the V4 and V4L, as this seems to help sensitivity a bit. Please consider this patch. And if anyone at Osmocom wants to try a V4L, please let me know. An initial run of the V4L models should be ready in about 1-2 months. Regards, Carl Laufer RTL-SDR Blog

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[PATCH] cmake: use GR_INSTALL_LIBRARY to install modules (gr-osmosdr)
by Mario Haustein 08 May '26

08 May '26

Dear gr-osmosdr maintainers, attached you will find a patch which uses the GR_INSTALL_LIBRARY macro to install the module library. Otherwise no library files will be installed. Kind regards Mario Haustein

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[PATCH] cmake: use GR_INSTALL_LIBRARY to install modules (gr-iqbal)
by Mario Haustein 08 May '26

08 May '26

Dear gr-iqbal maintainers, attached you will find a patch which solves https://osmocom.org/issues/4950. Kind regards Mario Haustein

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[PATCH] cmake: fix usage of GR_REGISTER_COMPONENT according to current GNU Radio
by Mario Haustein 08 May '26

08 May '26

Dear gr-osmosdr maintainers, attached you will find a patch which solves https://osmocom.org/issues/6986. Kind regards Mario Haustein

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Question about PLL setting and vco_power_ref in tuner_r82xx.c
by WangRZ 07 May '26

07 May '26

Hi all, In src/tuner_r82xx.c of the rtl-sdr project, I see the following code: uint8_t vco_power_ref = 2; ... if (priv->cfg->rafael_chip == CHIP_R828D) vco_power_ref = 1; vco_fine_tune = (data[4] & 0x30) >> 4; if (vco_fine_tune > vco_power_ref) div_num = div_num - 1; else if (vco_fine_tune < vco_power_ref) div_num = div_num + 1; ... It seems that vco_power_ref is derived from the chip type, and used to determine the VCO's division. However, when I use an R820T2 with a 16MHz crystal, I have to manually set vco_power_ref = 1 to get it working normally. This confuses me. Could someone explain the mechanism of the PLL setting? And why is vco_power_ref determined solely by the chip type in the original code? Thank you. Wang Rz

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