More noise than without

The result was disappointing.
Without the amplifier I had about 6 channels (FM). The amplifier causes Scan While in more places in (20), but most places which are just noise. The 6 stations that I had without amplifiers get to the amplifier a much stronger noise. The only channel that was previously really clear with amplifier has a not to be listening noise.

At first I thought the item is defective, and only a dummy, but I then measured again and saw that really needs the part 8 mA current.

It may well be that there are situations where the supply is functioning, but for me it is worthless in this form.