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Showing posts from March 23, 2017

U3S continuing

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now using a FOX 27MHz TCXO in the Synthesizer v1.4 PCB
At 27.000.000 almost exact. The CAL setting for correction is disabled.
The 27Xtal  was generating around 27.003.0120
So now the drift is coming close to the K3 stability.
My old IC706  impresses me even more it can run WSPR stable at 144.489 MHz without the Icom optional 30MHz TCXO (obsolet)
Will not order a 30MHz VCXO  with the experience about TCXO's  i have now.



QRP LABS note about some TCXO having discrete frequency steps is unfortunately valid for this  FOX924-27.00
Intolerable a for PLL frequency reference of course.
If i had known that, obviously i would  have chosen a better suited type.
Taitien 27MHz VCXO might be a better choice it is a bit gambling.
Now a Taitien 27MHz is used the Si5351a is very stable stand alone and generates high quality WSPR tones.
The specification does not mention the method ,  temperature compensation or correction?  
My  23cm l.o 1050MHz by DF9NP PLL  uses a TAITIEN 10MHz VCXO .
It doe…