The hack 0.9 describes how to modify a RTL2832U+R820T dongle as RF generator.

I connected the generator to two RTL2832U+R820T receivers and I assumed the generator to be in the 0.5-1.5GHz range as indicated by the receivers screens.

That is not correct because the RTL_SDR receiver is sensitive to even harmonics of the tuning frequency.

The generator output is in the VCO range 1.770 - 3.54 GHz.


The error became evident when I connected the generator to a R&S FSV spectrum analyzer and got the following measures:








 Spectrum analyzer settings: Center Frequency 1.8 GHz ; Span 3.6 GHz, Att 10dB.




Generator SDR# tune: 1GHz,

output spectrum: 2.0GHz (2x)










Generator SDR# tune: 0.9GHz,

output spectrum: 1.8GHz (2x)










Generator SDR# tune: 1.4 GHz,

output spectrum: 2.8GHz (2x)







When the generator is tuned to lower frequency the VCO is tuned to higher harmonics (power of 2).

Generator SDR# tune: 0.5 GHz,

output spectrum: 2.0 GHz ( 4x)







The generated signal is weak while clean.


The RTL2832+R820T RF GENERATOR hack 0.9