Small but compact with restrictions on the residential area

Looking for a good DVB-T antenna I became aware of the Active DVB-T Indoor Antenna Antenna with 20dB gain. According to the reviews, this antenna should be very good. I can not confirm, unfortunately. We live on the third floor, there, this antenna is working wonderfully. The image is sharp and clear. The antenna is on the window sill inside.
With my parents, however, the antenna failed. We live about 500 m distance apart. My parents live on the ground floor. Here, the antenna does not work as well or having many transmitters glitches in the form of pixel errors, picture freezes or no signal. The antenna is there and also the inside on the windowsill. The stations are shown for the most part only with disturbances.

But when putting the antenna outside on the outer windowsill, so the picture is better. However, since the antenna is purely indoor antenna, it can not stand outside unfortunately. Although she is said to have a gain of 20dB, it creates not to provide a reasonable signal in the area of ​​the ground floor there, so that the transmitters are trouble-free.

The same TV set was taken, which is with us on the third floor.

Conclusion: My experience amounted sure you stay on the third floor, the picture is top. You live on the other hand on the ground floor a flop. Thus, only conditionally recommendable.