Date: Thu, 19 Mar 2015 21:23:03 -0230 (NDT)
From: jcraig@mun.ca
To: rsgb_lf_group@blacksheep.org
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Subject: Re: LF: TXing WSPR on 630m on a Raspberry Pi, Stefan in QRPPPP...
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Thanks for this, Stefan.  The pi on the desk may be put to work soon!
73
Joe VO1NA

On Thu, 19 Mar 2015, DK7FC wrote:

> Joe,
> See attachment. You can simply tell the program your call and locator and 
> frequency and duty cycle and run it from a command line.
>
> 73, Stefan
>
> Am 19.03.2015 01:02, schrieb jcraig@mun.ca:
>> Hi Stefan,
>> 
>> That looks very nice.  Is there a script for generating RF with a pi?
>> A 500Hz tone is easy but for higher freqs it seems a DDS is needed.
>> 
>> 
>> 73
>> Joe VO1NA
>> On Wed, 18 Mar 2015, DK7FC wrote:
>> 
>>> Hi MF,
>>> 
>>> Today i've got i 3rd Raspberry Pi. I quickly installed the WSPR softaware 
>>> and since a few minutes i am transmitting WSPR-2 on 630m, my usual 
>>> frequency 475.685 kHz.
>>> 
>>> I'm directly using the GPIO output pin, without an amp stage behind! The 
>>> rectangular 3.3V output voltage is passing a cap and an isolation 
>>> transformer (FT50-77) as well as a simple pi-filter, because it is a 
>>> Raspberry pi! ;-)
>>> 
>>> See: 
>>> https://dl.dropboxusercontent.com/u/19882028/MF/Raspberry%20Pi%20B%2B%20WSPR%20TX.jpg 
>>> 
>>> I measured an output power of about 10 mW at 50 Ohm. It is now connected 
>>> to my MF antenna and transmits in a 100% duty cycle. I still have to learn 
>>> how to reduce it but this will not take long.
>>> 
>>> With 10 mW TX power i managed decodes by 3 stations now.
>>> 
>>> 3 spots:
>>> 
>>> Timestamp     Call     MHz     SNR     Drift     Grid     Pwr     Reporter 
>>> RGrid     km     az
>>> 2015-03-18 20:32      DK7FC      0.475684      -21      0      JN49ik 0.01 
>>> DH5RAE      JN68qv      345      98
>>> 2015-03-18 20:12      DK7FC      0.475685      -24      0      JN49ik 0.01 
>>> F1AFJ      JN06ht      667      247
>>> 2015-03-18 20:06      DK7FC      0.475683      -27      0      JN49ik 0.01 
>>> DL1DBC      JO41bi      217      349
>>> 
>>> 
>>> 
>>> Does someone have good ears to get a decode from me? :-) It is a 
>>> challenge! :-)
>>> 
>>> 73, Stefan/DK7FC
>>> 
>>> PS: The signal is so weak that my RX antenna frontend is not overloaded, 
>>> so at that power level i can transmit and receive to the same time :-)
>>> PPS: A small amp stage will follow soon, i intend to use an BS170 running 
>>> at 5 V.
>>> 
>> 
>