My HS-7955TG jitters when I turn on the TX... why?

[suicideneil]

Not really a characteristic no- sometimes they can buzz a little if they havent perfectly re-centered & the truck is on the ground, but they shouldnt really jitter alot like that; does it do the same thing with the wheels off the ground?

You might be able to adjust the dead-band on your radio so that the servo isnt quite so sensitive to the center position, though Im not sure what settings are available so it might take some fiddling to get some results.

If you had a different radio you could test it with that, or it might be worth making sure the servo wires are routed away from the esc and rx as much as possible too, and braid the motor wires perhaps ( try everything more or less )