I plan to experiment with wire antennas some so I purchased the 6400 without the optional antenna tuner and instead purchased the MFJ-993B auto tuner. I think I should have read the MFJ manual deeper before purchasing. I have the 6400 at the back of the house close to the antenna feed and operate using smartSDR from my radio shack in the front of the house connected to rig by ethernet. I read that the MFJ tuner auto tunes with any transmit signal and assumed that meant could be used remotely. But now in reading more closely it is important not to ever have it "auto tuning" with more than 10 to 20 watts. There is a tune button not he MFJ unit that is to be pressed before sending the lower power signal. Has anyone found a way to use the MFJ-993B tuner when operating remotely on the local area network with SmartSDR? They have a remote box, but it appears to be designed for a short serial connection to the tuner.