[Discuss-gnuradio] Components of BasicTX

[Mathias Coinchon]

Hi,

I am using BasicTX daughterboard to generate a VHF signal around 228MHz.
For this a complex signal is generated at -28MHz  leading normally to harmonic 
components at 
128MHz-28=100MHz
256-28MHz=228MHz (wanted signal)
384-28MHz=356MHz

However looking at the spectrum (see attached), I still see powerful components 
at
128+28=156MHz
256+28=284MHz

Is it normal or is is a missconfiguration from my side or an I/Q gain inbalance 
?
Is there a way to avoid these 156 and 284MHz components ? (they are hard to 
filter compared to other one actually)

Thank you

Mathias

basictx.jpg
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