Dear Pimatic Users
I would like to share with you a little experience I have made:
I have three raspberry pi 2 running in total, one with Librelec/KODI, one running Owncloud and the third and last one hosts my pimatic system. I have setup homeduino with an Arduino Board 433mhz Receiver and Sender. Sending has worked fine since day 1. With receiving however I had massive problems with bad reception. more than 2-3 meters was not possible with GS-IDWS 07 door contacts that I wanted to install on each window. I invested hours with different setups, receivers, antennas with no luck so I resigned and stopped the project and kept pimatic with the functionalities that worked.
End of the year I changed my Internet DSL Provider. The switch worked fine and for the first time in years I checked by Router DSL Connection stats (Fritzbox) finding that there is an extremely high rate of unresolvable errors per minute on my Fritzbox (up to 800 per 15 min) and a low " Störabstandsmarge" (sorry no idea what the english tranlation is) of only 6 db. My connection has always been Ok but I have long experienced dropped calls and lost connections but never did any investigation. I was close to contacting my new provider but then did some research and found articles to check the location of the router and cables that are being used. I unplugged everything and the error rate immediately went down to zero. Then I plugged back all connections one by one and checked the error rate. It remained zero UNTIL I plugged in the network cable of my pimatic Raspberry Pi, immediate dozens of errors appeard. I changed the cable, same result. I was under the assumption that the 433mhz Transmitter was maybe causing this but unplugging it from the raspberry showed no improvement, so I thought the Raspberry itself had a defect. I was close to buying a new one when I tried one last thing and changed the power supply to one of my other Raspberries and voila: no errors with pimatic, arduino and and 433mhz parts running full 
I immediately checked the 433 mhz reception and was happily suprised that it has largely improved. I now have full and reliable reception from all perimeter sensors in my 85qm apartment and even beyond.
This is the ebay ad with the power supply unit in doubt: https://www.ebay.de/itm/Netzteil-5V-3A-Ladeger-t-Schalter-Micro-USB-f-r-Raspberry-Pi-2-3-Android/182519821721
Baseline: Dont buy this one and when you experience bad network performance and 433 mhz reception issues maybe it is worth changing the power supply unit.
Hope this helps.
