LF: MF WSPR remote RX experiments

[DK7FC <73dk7fc@googlemail.com>]

Hello MF,

I've continued with tests for my remote RX station.

Right now i am running a Raspberry pi on a 7 Ah battery. It drives a 
WLAN stick and a simple USB sound card, feeding audio via a vorbis steam 
through the web. A MF receiver (LO = 461 kHz) is running on the same 
battery. The RX is connected to the same antenna where my MF/LF grabber 
is connected to. Ah and the Raspberry pi is powered by an external 
switch mode regulator, 12V=>5V! All in all this consumes about 250 mA @ 12V.
I am playing the vorbis audio stream (about 220 kbps) directly in 
SpecLab where i can see the full MF spectrum. SpecLab is running a 2.5 
kHz wide band filter and frequency converter feeding a virtual audio 
cable. Finally this is connected to WSPR-X... Now i can compare the SNR 
difference on both, the grabber RX and the remote-RX  plus web data 
stream. The receivers are technically nearly identical as well as the 
filter settings.
There is some time delay but it is not problematic, no correction needed 
for WSPR. I'm getting quite good results from the first attempt, a SNR 
difference less than +- 1 dB.
The remote system is not running in the garden now, just a local test.

WSPR reports on MF via web streaming are coming in at DK7FC/RPI.

The test is running for a few hours now :-)

73, Stefan/DK7FC