DL9LBG WSPR transmitter
April 22nd: DL9LBG is not whispering today - sometimes I prefer man made cw operation.
This webserver and the WSPR generator/decoder (Weak Signal Propagation Reporter) both work on a Raspberry Pi mini computer located in Lütjenburg/North Germany (Locator JO54hh).
Currently DL9LBG whispers on 3.570065 MHz (80 m band) with a tx fraction of 20 % (transmitting approx. every 12 minutes).
The WSPR software by K1JT is running on a Raspberry Pi which is connected via a cheap USB audio dongle to an FT-857D which produces about 2 watts (33 dBm) hf output. I use an endfed quarter lambda antenna (length 20.5 mtrs) about 18 meters up from the ground. The water tap in the kitchen is a great ground connector (in my case) so I can feed the antenna directly with low impedance without any balun, LPF or tuner.
WSPR transmitter plus webserver on one mini computer and the power input is only 3.5 watts. Good power efficiency, I think. On this old Raspberry Pi 2 additionally an MMDVM-DVMEGA does a good job as a local DMR-/C4FM-YSF-Hotspot on 433.675 MHz (WSPR and webserver take few ressources, there's enough mem and CPU-power left for MMDVMHost).
Pse QSL to michael [ät] dl9lbg.de - tnx!
SWL reports will be confirmed via QSL bureau, eQSL or QRZ.com postal address.
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