"Our solution has been to develop a microprocessor-based RF signal sampler that periodically checks your RF output, computes its IMD locally, and automatically sets the sound card's audio level to provide the highest RF output with minimum distortion."I may have to purchase this kit and try it out. It looks simple to build and if it preforms as stated would be a very good tool for PSK31. It runs on Windows 95 and newer.
Check it out at: