I resurrect this topic, because we are still experiencing the problem and we discovered something unknown before.
Up to now, I was under the impression, that the audio archive is trunkated because of the internet connection cutting out during the 30 minute archive period.
So I was asssuming that the only problem is that the file is shorter, nothing else.
However recently I realized that the short archive file has a corrupted sequence of audio as welll
In the file LHBP-Twr-Mar-22-2018-1130Z.mp3, the archive file is only about 12 minutes long.
But it's not the only problem.
It starts with conversations taking place around 11:45 and the first 3 minutes in the archive are actually happening AFTER what is stored from 11:05 Z.
So the archive file is messed up from audio sequence point of view, a later portion overwrites earlier portions!
If you are interested in pursuing a solution to this, I will connect an audio time stamp input to the feed for 30 minutes, so we can verify exatly how what gets recorded in 30 minutes, and exactly what is overwriting what part in the archive file.
I realized this problem when listening to a go-around from NAX 1550. Surprisingly, NAX signs into the ATC saying "hello again", and only then it goes around. This got me suspicious, and found that all conversations in the beginning of the file actually took place AFTER what was recorded at the end of the file.