Hi Joe,
As you can see on the image, you can directly generate a RF
signal. It works up to 250 MHz, as i read. So you can use this
arrangement for all bands up to 2m !
All informations i needed to install/run the API can be found here:
https://github.com/threeme3/WsprryPi
73, Stefan
Am 19.03.2015 01:02, schrieb [email protected]:
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.
|
|
