So i made two tests with oscillator and the problem seems not to be the supply.

Test 1: I connected the RX-RM-5V receiver's 5v pin and gnd to the external power supply. Capable going 5A, its laboratory PSU. Then i measured module's data pin with oscillator, and the signal ok and clean, i saw receiving moment clearly. There is very little noise. The Raspberry was not connected with my module

Test 2: I connected the module to the Raspberry Pi 3 's gpio pins. 5v to 5v and gnd to gnd Then again i monitored the modules data pin with an oscillator. Results showed that the data pin had huge constant 1kHz noise on the data pin. So i assume it picks up noise from pi gpio or something.

I also made a low pass with 700 Hz cut off and this works ok but i had no luck gaining the distance. The data comes to the receiver between 300-400 Hz frequency. Hard to tell the exact frequency. I tried to make a bandbass filter but the high pass side seems not letting the data through with 20 Hz cutoff.

Theres an article on the internet which talks about module for Pi which is basically filter module for RF projects. They have bandbas filter which filter broadband out. So there is something which Pi dont like about RF signals.

Right now im waiting two diffrent receivers from ebay

So i made two tests with oscillator and the problem seems not to be the supply.

Test 1: I connected the RX-RM-5V receiver's 5v pin and gnd to the external power supply. Capable going 5A, its laboratory PSU. Then i measured module's data pin with oscillator, and the signal is ok and clean, i saw receiving moment clearly. There is very little noise. The Raspberry was not connected with my module

Test 2: I connected the module to the Raspberry Pi 3 's gpio pins. 5v to 5v and gnd to gnd Then again i monitored the modules data pin with an oscillator. Results showed that the data pin had huge constant 1kHz noise on the data pin. Module is receiving data on much lower frequency than the noise. (300Hz-400Hz) So i assume it picks up noise from pi gpio or something.

I also made a low pass with 700 Hz cut off and this works ok but i had no luck gaining the distance. The data comes to the receiver between 300-400 Hz frequency. Hard to tell the exact frequency. I tried to make a bandbass filter but the high pass side seems not letting the data through with 20 Hz cutoff.

Theres an article on the internet which talks about module for Pi which is basically filter module for RF projects. They have bandbass filter which filters broadband out. So there is something which Pi dont like about RF signals.

Right now im waiting two diffrent receivers from ebay...