Hi MF,
Got no answer from PE1NNZ so i spent a bit more time and effort to
'understand' the C-code, i.e. find the correct line where to put a '4*'
to get what i want. I found it (it is: double freq =
4*centerFreq + 4*((double)(-511 + i))*symOffset/3.0; ).
I also compiled it successfully. Now i can externally set the same
frequency (e.g. 475685) but the output and frequency shift is 4x
higher. This can be passed through my /4 CD4013 stage, which is used to
generate a perfect rectangular, opposite phase signal, after the input
signal has been distorted a bit while passing an optocoupler (EMC
stuff...).
I know several OMs are using such divide-by-4 stages, which, so far,
didn't allow to transmit WSPR. Now, with the Raspy these days are gone,
at least for me.
If some one is interested, i would of course share the code (you
already see it and just need to find the line in your wspr.c file).
I'm now trying to run a bit more power as usual since the Raspi is
directly connected to the (real) PA:
https://dl.dropboxusercontent.com/u/19882028/MF/Raspi_to_QRO_link.jpg
73, Stefan
PS: Ooooh, of course it could be that someone did the same before me,
maybe even better and so on... so it is maybe not a 'first'
whatever!!!!
Am 27.03.2015 14:27, schrieb DK7FC:
[...]And i
wrote an email to PE1NNZ and asked to a modification of the C-program
to generate a signal with 4x higher FSK shift. Then it it would be
possible to use that version for OMs having a divide-by-4 stage in
their PA (to get a perfect 50% duty cycle and rectangular shape (after
passing optocouplers etc)).
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