Test Transmit Signal for nRF24L01 transreceiver
I invite you to explore the world of software defined radio. Most all of the dedicated purpose units will easily cover 2.4GHz. I'm using a HackRF One for exactly this. A new contender is the Lime SDR Mini, which is only $139 USD. These things are invaluable for anyone working with RF, since you can see exactly how much bandwidth is used, what else is on the band, etc.