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Re: zBitx +-2 MHz transmit spurs? --> SHOWSTOPPER for transmitting

 

It looks like amplitude modulation with ~2MHz signal. So maybe indeed it is something related to power supply voltage stability? Maybe instability of the voltage controller, or certain circuit with current consumption changing periodically with ~2 MHz, which causes the power supply voltage fluctuations?
If I receive my zBitx today, and if it produces that effect, I can take a look at it.

73,
Wojtek SP5DAA?



wt., 15 kwi 2025, 23:59 u?ytkownik zl1ujg via <zl1ujg=[email protected]> napisa?:

Additionally loading the SI5351A output heavily pulls it out of its self-limiting range, degrading composite noise.
This can be seen in the work that Hans (QRP-Labs) has done on his Phase noise tests.?
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