Review on Wireless 433MHz RF Module Receiver With 4 Channel Output – QIACHIP RX480E (20 Pcs) by James Vachon

Took receipt of the product and set it up on a breadboard. After developing the circuit according to the seller's instructions I wanted to examine the transmitter output on a spectrum analyzer so I powered up the transmitter with a 9 volt battery which is well withing the recommended voltage range, I could not detect any RF output in the 433 ISM band. I did locate a low level incoherent noisy signal at about 540 MHz. I returned both the transmitter and receiver to ebay and asked for a replacement. We will have to see if the replacement works any better. More to come.This is my second review. The replacement arrived and this one worked as advertised. The receiver learned the code with no issues. I connected an SMA short jumper to the antenna terminal and measured the transmitter output power into a 50 ohm load. It produced about 10 dBm.