Royal SRS with A-123 and Differential Horizontal Tails

  • Richard, this is my first PowerBox product and I have some questions. I am very impressed so far.

    Model is 1/5 F-16. About 20 flights so far using Futaba 18MZ, R7008 Sbus, on Smartfly board with three decoders. I have removed the entire onboard radio system and am now installing 2 R7008 Sbus, Royal SRS with PowerBus to simplify the install, improve safety, and save weight. I have not connected anything so far. Still working out my channel mapping plan on a spreadsheet. I had used 17 channels before but I am planning on using one channel each for leading edge flaps, flatirons, and elevators and servo matching. This should give me extra channels for iGyro adjustments during test flights.


    1. I am using two A-123 2S 2600 mah flight batteries with an output of 6.6v. If I set the output voltage A and B to 7.4v, will I get the full 6.6v from the batteries to the servos?

    2. With 6.6v input and output voltage A and B set to 7.4v, what voltage will the receiver see while using Sbus2 for telemetry?

    3. When controlling the Royal SRS on and off with the SensorSwith do I have to disconnect the batteries for long term storage to avoid battery drain?

    4. I have been flying the jet using flaperon(aileron) and differential horizontal stabilizer mix for roll control. How do I set up differential stabs using the internal iGyro?

    5. I am using camber flaps in the 18MZ for flaperon flaps. Will I still get roll control and gyro stabilizing when camper flaps are lowered?

    6. Is it smart to use the A (Red) output on one side of the aircraft and B (Black) output on the other side?

    7. There all servos and electronics are PWM. There are 3 PWM Adaptors, one mid fuse left side, one mid fuse right side, and one in tail. The tail adaptor is in series with the left side adaptor. Can I assign both A and B outputs to the tail Adaptor?

    8. I am using the PowerBox dual output jet smoke pump. Can I connect the power to the A-123 3S 9.9v ECU battery or must I connect the power to the Royal SRS for the lower voltage?

    9. My Royal SRS was purchased new in November 2016. Do I need the update for using the R7008 Sbus for use with the new LBT protocol as mentioned in the "Futaba 7008 and powerbus on royal" forum posts? How do I know if my Royal SRS has this update?

    I'm sure I will have more questions as I get started. Thanks in advance for your help.


  • Hello,

    a lot of questions, I will try to answer all:

    1: Yes the output is then the battery voltage (-0.3V)
    2. The receivers has the same voltage. For example 7.0V input, the receiver gets 6.7V. Don´t use it for telemetry. If you want the exact battery voltage use the teleconverter. With that you get all data:
    3. Normally not. One year is no problem, but when you go into winter break, disconnect it.
    4. The Gyro for ailerons in only on the outer ailerons.
    5. In the best case the ailerons with gyro stabilization have no flap- is that possible?
    6. Yes you can do that
    7. The PowerBus output A and B have the same signal- the difference is the output voltage you can set.
    8. You connect the pump to the Royal
    9. Let me know what numbers you read at the startup.

  • Richard,

    My new Royal SRS at start up shows V12.7.

    Do I need the update for using the FUTR7008 Sbus receivers for use with the new LBT protocol as mentioned in the "Futaba 7008 and powerbus on royal" forum posts?