[J57ltr]

Break out your meter and measure the wires on the pot installed on the servo tester. The outside pins should read about 5K. The middle is the wiper, it moves along from highest to lowest. so if you are on one of the outer pins the resistance will rise (or fall) as you turn the pot. The leads on the throttle will be the same if they both are the same resistance then you'll be OK. basically you will have to just remove the pot and replace it with the throttle control. Although since most ESC's have to be in a neutral position and the throttle is probably maxed at one range or the other so the ESC might not arm.

A pot is nothing more than a resistor that has a sliding wiper that when centered on the resistor will read half of what the total value is. So if you are in the middle the outside (lets say left) leg and center will read 2.5K and from the other outside leg (lets say right) and the center it will read 2.5K. As you move more to the right the left and center will start to increase in value while the right side and center will decrease.

Jeff