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LF: WSPR at 4xf from a Raspberry Pi

To: [email protected]
Subject: LF: WSPR at 4xf from a Raspberry Pi
From: DK7FC <[email protected]>
Date: Tue, 31 Mar 2015 22:46:34 +0200
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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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