How to create a carrier wave with GeneratorX? Also, which frequency is best for carrier wave?

I don't recommend using a carrier because you can get frequency fatigue. Instead, set a minimum frequency in the Setting tab in the Frequency Limits section in the > field. This will cause Spooky to find a harmonic of your frequency that will penetrated better via contact mode. A decent minimum frequency is 1Mhz, but 3 MHz is OK too.

But if you must use a carrier, I see a lot of people using 3.1 MHz. You could also use dynamic carrier, by setting the Out2 minimum to 3 Mhz or higher. This works when you have audio frequencies in your set, but is not so great if your frequencies are already in the MHz range. But this failing is true if you have a fixed carrier, because you add an unnecessary modulation.

For more details, please check the link:
https://www.spooky2.com/forums/viewtopic.php?f=115&t=9513