Hi,
My name is Ketil, I’m from Norway, and this is my first post here. Pleased to meet you all! 
After running The Things Gateway indoors for some weeks, I finally got around to mounting an outdoor antenna last weekend. I was delighted with the result: The gateway was now picking up packets from nodes almost 5 kilometers away. My delight was short-lived, however: After just a few hours of operation with the outdoor antenna, the gateway went deaf and is now only picking up transmissions from the weather station I have in my garden.
I examined the past transmissions (from my garden), and noticed that the RSSI before the range drop averaged to between -50 and -60, while the average after the drop is between -80 and -90. The SNR is more or less the same as before – between 9 and 12, approximately.
After some searching, I found a few similar issue reports on GitHub: https://github.com/TheThingsProducts/gateway/issues/44
Are the above symptoms indicative of a defect LoRa card? Or are there other explanations for the sudden range drop?
Kind regards,
Ketil