RE: Programmer for Digital Servos
I'm a long way from considering myself an expert here and my experience is only with the Hitec programmer. I'm told you can assume the servos are linear in their motion from neutral to end-point. This makes it important to match the neutral and endpoints to the same values physically. What this means to me is that I adjust the servo lever so that it is exactly 90 degrees to the servo case and set that as the center point with the programmer. I then use the programmer dial to adjust the endpoint of the servo in one direction the the desired maximum and set the left or right endpoint on the programmer -- repeat for the other direction. This will usually get you very close. Use your TX (subtrim set to 0 and endpoints set to some equal value between 100 and 140.) Then 1st make sure the surface is at neutral by adjusting the clevis and then measure the endpoints. If the endpoints are off go back to the programmer and make minor adjustments to each endpoint according to how much they are off. It usually takes 2-3 transistions to get the the values you want. This is the way to match servos.
Now, I'm not really familiar with the deadband adjustment but can hazard a quess for its use. You can only increase the deadband, it is factory set for its minimum. If for some reason you have a control surface that has a little torque away from neutral and you find your servo constantly chattering (digital servos sound like whining) you can probably increase the deadband to the point that this chattering/whining stops.
Another adjustment is speed. Servos come from the factory set for their maximum speed. The programmer allows you to slow them down -- examples for that requirement should be easy to come up with.
Another adjustment is the direction of the servo -- you can reverse it.
The rest of the capabilities of the Hitec Servo Programmer can be used for any servo, any brand, any format. It lets you test the servo responses and in some cases allows you to "burn-in" a servo, run it for a period of time to make sure it is not going to fail. It also lets you measure the pulse width being put out by the TX for any given neutral point or any position of the TX control stick. E.G. The neutral position of a Hitec TX control stick is 1500ms. The neutral position of a Futaba TX is ~1518ms.