Using the Innovation First Victor 883 speed controller with the Hitec Prizum 7 radio. Hitec manuals in .pdf format online
In this example I'm controlling Dual Bosch 750 W motors for single stick tank type steering. The robot has a drive motor for each side and a Victor controller for each motor the channel mixing is programed in the Hitec Prizum 7 radio.

 1). Connect each controller to plus 24 VDC and ground as per the manufacture's instructions. Do not power them up yet

2). Connect the controllers output to the Bosch motors observing the motors polarity.

 3). Connect the left motor controller servo wires to the receivers channel #1.

 4). Connect the right motor controller servo wires to the receivers channel #2.

 5). Power up the transmitter. After power up press the UP and DN buttons at the same time. Cycle through the menu using the DN button until the letters EPA (end point adjustment) appear in the left hand corner of the display. Next to these letter will be the channels 1 to 7. Press the CH button until the cursor is above channel #1. Press the + button until the display reads 125%. Press the CH button again and use the + button to set channel 2 to 125% also.

6). After the End point adjustments for both channel 1 and channel 2 are set to 125% you need to check the radio trim adjustments. Press the DN button until the display shows a CH followed buy the numbers 1 through 7. You need to set channel 1 and channel 2 to 0% trim the letters TRM will be flashing next to their current values.

The Hitec Prizum 7 transmitter has 4 mixing modes They are displayed with a three letter designator. There is ELE for elevon mixing, UTL, FLP for flaperon mixing. DIF for diferential mixing. For tank type steering on the right joystick use the ELE mixing mode.

7). Entering the Elevon mixing mode. Power down the radio. Press both UP and DN buttons at the same time and turn on the transmitter power switch. Press the DN button several times until the display is flashing the word OFF. Press the CLR button to turn the mixing function ON. Using the + button, cycle through the mixing functions until the letters ELE are flashing. This is the elevon mixing mode for channel 1 and 2 on the right joystick. Leave this function flashing.

8). Once you have enabled the ELEvon mixing mode you are ready to calibrate the controllers.
Calibrating Victor controllers.pdf file
Turn on the receiver and power up the motor controllers. The speed controllers should have a steady Amber LED light on and neither motor should be turning.
Start with the controller for the right motor. Press and hold  the small calibration switch on the controller with a paper clip The LED should flash Red and Green (this indicates calibration mode). Move the right joystick straight forward to the top of its travel. Return the the joystick to center. Move the joystick to the bottom of its travel. Release the controllers calibration button the LED will flash Green indicating a successful calibration of the controller. Now press the calibration button on the left motor controller and repeat the procedure. Now your ready to rock.

Test the drive motors for proper operation. Full stick Upward should spin both motors and both controllers should have a Green LED lit. Full stick Downward should spin both motors and both controllers should have a Red Led lit. It may be necessary to adjust either channel 1's or channel 2's trim settings in programing to get the motors speed's to match.

The mixing function in the transmitters built in program will provide the differential turning for single stick tank type steering depending on the amount of joystick movement that you apply to the joystick.