New G4DDK preamps upgrade

System sensitivity improved by 50K

After few months of operation, today i managed to install new G4DDK preamps, build by hints from RW3BP article with system temperature about 70K, about 50K better than former preamps.

Some more photos of preamps.

Marko S57UUU wrote a software for easy NF measurement using RTL-SDR dongle, so everything i need is to run the software, press 1 to store ground noise, then wind the elevation, press 2 for cold sky and voila, there are the figures:

Comparission between yesterdays and today's recording shows nice improvement.

Picture of object  in Hydra, obs: C0920M12 name:  091805-120541 RA: 09:18:5.78 DEC:-12:05:41.3 pwr mJy: 40849.90 apparent power mJy: 36452.00

Old preamps, TSYS ~ 130K

New preamps, TSYS ~ 70K