Timeline for Calibrating RTL-SDR Power with 50 Ohm Load and Thermal/LNA Noise
Current License: CC BY-SA 4.0
20 events
| when toggle format | what | by | license | comment | |
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| S Mar 8, 2021 at 2:00 | history | bounty ended | CommunityBot | ||
| S Mar 8, 2021 at 2:00 | history | notice removed | CommunityBot | ||
| Mar 6, 2021 at 6:00 | history | tweeted | twitter.com/StackElectronix/status/1368078903198310400 | ||
| Mar 2, 2021 at 7:07 | comment | added | tomnexus | By the way, it's easy to build a noise source for that frequency range, with an ordinary small glass zener diode. I think about 12 V is the noisiest. Pass a small current through it. Build it right on an SMA connector, maybe with a 1 K smd resistor and couple the noise out with an smd capacitor. This will save you one LNA in your noise chain. The noise output will be up to 12 dB ENR, but it is not very flat. | |
| Mar 1, 2021 at 15:50 | vote | accept | Macuser | ||
| Mar 30, 2021 at 16:32 | |||||
| Mar 1, 2021 at 15:43 | history | edited | Macuser | CC BY-SA 4.0 |
Removed images since they are already posted in the answer.
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| Mar 1, 2021 at 3:04 | history | edited | Macuser | CC BY-SA 4.0 |
added 73 characters in body
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| Feb 28, 2021 at 20:24 | history | edited | Macuser | CC BY-SA 4.0 |
Updated main question
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| Feb 28, 2021 at 20:14 | history | edited | Macuser | CC BY-SA 4.0 |
Updated image with more equations/variables worked out
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| Feb 28, 2021 at 19:32 | history | edited | Macuser | CC BY-SA 4.0 |
edited body
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| Feb 28, 2021 at 19:11 | history | edited | Macuser | CC BY-SA 4.0 |
edited body
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| Feb 28, 2021 at 18:18 | history | edited | Macuser | CC BY-SA 4.0 |
Updated image with measurement and more equations worked out.
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| S Feb 28, 2021 at 0:34 | history | bounty started | Macuser | ||
| S Feb 28, 2021 at 0:34 | history | notice added | Macuser | Draw attention | |
| Feb 25, 2021 at 22:43 | comment | added | Marcus Müller | again, there's different analog frontends for RTL2832U, be sure your actually has a disableable AGC. Just because you can set a checkmark in software doesn't mean the hardware does something. | |
| Feb 25, 2021 at 22:16 | history | edited | Macuser | CC BY-SA 4.0 |
Updated image
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| Feb 25, 2021 at 22:06 | history | edited | Macuser | CC BY-SA 4.0 |
Added comment on 50 ohm load power calculation in watts and dBm
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| Feb 25, 2021 at 21:59 | comment | added | Macuser | @MarcusMüller You can turn off hardware AGC in GQRX. For the rtl_sdr command, the AGC is turned off by default when you specify a gain. | |
| Feb 25, 2021 at 21:54 | comment | added | Marcus Müller | I'm not 100% sure, but I think a few RTL-SDR dongles have an AGC that can't be fully turned off, which would render your calibration useless. Make double sure this is not the case for your device! | |
| Feb 25, 2021 at 21:51 | history | asked | Macuser | CC BY-SA 4.0 |