Ten Tec radios are incredibly easy to tune, and they will tolerate anything under about a 3 to 1 SWR without complaining, although of course, I recommend the best SWR you can manage. I use a manual tuner, so I have written down ballpark settings for the frequencies I use on each band. This is important, and makes things very simple once you get some settings established as starting points. As RF out on any rig wants to see as close to a 50 ohm match as possible, you should be able to use settings you have used before, or very close, on another radio.
I have a Triton IV Digital, and had a 540, and they are just alike except for the digital readout. Turn the ALC control full clockwise, and make sure it is pushed in, as pulling the control out is the blanker control. Make sure the Drive control is full counter clockwise, and with your tuner settings about where you think they should be, turn the Mode control to Lock. This is the keydown position for tuning. Gently turn the Drive control clockwise until the ALC light begins to glow. I have a shack full of Ten Tecs, and my experience is the Drive setting will end up somewhere between 5 and 7, unless your power transistors are weak. Expect between 90 and 100 watts, depending on which band your antenna is most efficient on. If you have any questions, feel free to e-mail me at firstname.lastname@example.org