Posts by gboxwood

    Following up on this. I also double-checked with Spektrum and they suggested the new ones, not the 9646's.

    They were already available in December, so I bought 4 and installed them 2 in the nose and 2 in the tail.

    Spektrum advised not to lengthen the leads to more than 36'' so I bought 2 36'' extensions and installed the rear ones as far back as possible.

    I maidened the model last Saturday (after a scrupulous range check) and it all went fine.

    Senza titolo by Giacomo Bosso, su Flickr

    Senza titolo by Giacomo Bosso, su Flickr

    Giant He-162 maiden flight, landing. by Giacomo Bosso, su Flickr

    Thank you for your help,


    Quick question: channels 17 and 18 on the PBUS are referred to as "switched channels", i.e., non proportional. Does this mean that if I operate the flaps via a 3-way switch those would be the channels to use?

    Or does it mean that they shall be used with functions operated by a 2-way switch, like the landing gear for example.

    This is not clear to me and during my previous attempt at using the PBUS I had issues with the flaps (which I assigned to regular channels, i.e., not CH17 and CH18). I hope that was the issue.

    Thank you,


    Many thanks!

    So another thing I was doing wrong, I had the antenna wires flat to the fuse, on the outside.

    They shall be perpendicular to it if I understand it correctly. I also installed them in 90 degrees arrangements.

    So I replace the 3 satellites I have right now with 3 of the carbon-friendly ones.

    Hi Guys,

    I'm using the Mercury SRS (one of the many I have) in a full carbon fuselage for the very first time.

    I have a Spektrum DX18 and I used 3 DSMX satellite receivers connected to the Mercury. I bent the aerials of the receivers so I can route them out of the fuselage but I believe this is not the right way to do it (now that I think about it...) as I'm basically reducing the active portion of the antenna.

    In fact, the Range Test* shows that the signal is lost as soon as I press the button to perform the test.

    What other Spektrum satellites shall I use? These ones?

    Thank you in advance for your help,


    * the range test works like this: with the engine on (this is a turbine model) walk at least 30 meters away from the model and then press a button which basically cuts the transmitter power and simulates long distance. The controls shall work properly and no glitches shall occur. In my case, the signal is completely lost and the surfaces do not move as well as the turbine shuts down.

    Hi Guys,

    sorry for dropping in the conversation but I had a similar question: when exactly do you trim your plane?

    If I follow the manual to the letter, I'll have to complete the iGyro setup by flying the model with the Gyro activated (from the take-off) at 0% gain and set to FM2 (ATT. ASSTN). I guess the gyro will not do anything because the gain is initially set to 0%. Then it will take over as I increase the gain until the oscillations begin, then I'll dial it back until the oscillations stop (at any given speed) and that gain setting will be saved by switching the FM to any other FM.

    What are the suggested flight modes for the maiden flight? I was thinking:

    FM1 = OFF

    FM2 = RATE

    FM3 = ATT. ASSTN.

    If this is the case, shall I start the flight assistant in FM3?

    Will this be the first flight or shall I first fly the model without the Gyro, trim it, land it and then complete the iGyro setup by flying it with the flight assistant activated?

    Sorry for the many questions but I'm confused (I guess you can tell).

    Thank you,


    Hi Richard,

    thank you for your reply. I figured out one of the issues and I was able to setup the left side completely (the RED BUS).

    It was my mistake: when you program the servo socket, what matters is to get the light flash rather than feeling the button being pressed in. Sometimes you press it in and you feel it clicking but the light does not flash and therefore your count is not aligned with that of the unit.

    2 issues remaining.

    1. After setting up the RED BUS, I tried the BLUE one to which I assigned the same inputs but with your numbering (5-6-7-8) as to avoid address conflicts.

    CH5, output D, function DIRECT 6, on servo socket 1, press 5x to assign CH5 to servo socket 1
    CH6, output A, function DIRECT 2, on servo socket 2, press 6x to assign CH6 to servo socket 2
    CH7, output B, function DIRECT 3, on servo socket 3, press 7x to assign CH7 to servo socket 3
    CH8, output C, function DIRECT 4, on servo socket 4, press 8x to assign CH8 to servo socket 4

    The BUS ADAPTER does not even light up when I connect the lead while keeping the SET button pressed in. No signs of life. It works because I was able to program it a while back while trying to figure it out.

    Maybe I have yet not understood what discriminates between BUS A and B in the powerbox, I assume the outputs, A to F being assigned to BUS B (BLUE) and G to X being assigned to BUS A (RED). It seemed pretty clear and intuitive to me.
    I also tried to disconnect RED BUS while attempting to program BUS BLUE but it didn't matter.

    2. On the BUS that works, if I plug the FLAP servo to the Powerbox socket everything is fine. If I then plug the servo into the BUS ADAPTER socket to which it belongs, the flap will move down by a tiny yet non negligible bit that throws the setup off. It only happens with the flap, not with the aileron and not with the rudder (elevator yet to be setup). This is strange.

    At the time being, I saw a lot of advantages with the BUS system and I'm usually very open to new systems and very willing to experiment with them but I think I'll drop this one because I don't have a clear understanding of what is going on and I don't want to risk my biggest model.

    Thank you for any advise,


    Good evening everyone,

    I'm setting up a big jet and I'm using the PowerBUS for the first time together with a Champion SRS. Transmitter is Spektrum DX18.

    My intention was to split the plane in half and assign each aileron, flap, rudder and elevator to a dedicated BUS to PWM converter, one connected at the B output and the other connected to the A output.

    A will be RED and it will power the left side of the airplane. B will be BLUE and it will power the right side of the plane.

    Super basic setup at the DX18, being:
    AILERON on 2
    ELEVATOR on 3
    RUDDER on 4
    FLAPS on 6 (AUX1)

    Output mapping at the Champion:
    BLUE bus:
    A=2=DIRECT 2
    B=3=DIRECT 3
    C=4=DIRECT 4
    D=6=DIRECT 6

    RED bus:
    S=6=DIRECT 6
    V=2=DIRECT 2
    W=3=DIRECT 3
    X=4=DIRECT 4

    Chosen for symmetry, not any other particular reason.

    P.BUS channel assignment (and this is where I loose it):
    CH1, output D, function DIRECT 6, on servo socket 1, press once to assign CH1 to servo socket 1
    CH2, output A, function DIRECT 2, on servo socket 2, press twice to assign CH2 to servo socket 2
    CH3, output B, function DIRECT 3, on servo socket 3, press 3x to assign CH3 to servo socket 3
    CH4, output C, function DIRECT 4, on servo socket 4, press 4x to assign CH4 to servo socket 4

    It is pretty clear to me and before I got started I thought I got it. I now got the rudder on the RED bus operating right but it appears that the other channels are not working or not right (I'll re-program the PWM adapter).

    The BLUE bus I cannot get it to work but there is something I'm missing for sure.

    Am I doing this right or am I asking for something that cannot be done?

    Any advise would be highly appreciated.

    Thank you,



    I'm new to the advanced features of my DX18 and I need more than 10 channels for my glider.

    This calls for the X-Plus expander module (extra 8 channels): is it something I can use with the Champion?

    Or is there another way?

    Thank you,



    Getting it to work is no problem. I set it to +35% ATV because anything lower than that will not pump any fluid.

    I was looking for a good mix with the throttle: right now I came to a mix where the pump kicks in between 95 and 100% throttle.

    I'd like to have it working from 20% to 100% throttle with an accordingly variable flow rate.



    Hi Richard,

    I tried the unit in the shop and it has the same behavior, channel 5 will not output anything to a servo.

    Maybe the update is an option but I'll need to buy a cable that the shop didn't have on stock.

    Also, what is the firmware version of your DX8? I'm still running the 2.05, I'll try to update that and try again tomorrow.

    Thank you,


    Hi, I tried what you suggested but it didn't work. Both selecting DSM2 and then re-binding in DSM2 mode didn't do any good.

    I tried the Evolution Spektrum and it works just fine.

    I'll go to the shop tomorrow, they have another Competition, I'll try that one and see if it works. If it does I'll exchange it and have them ship the unit back to you. If both don't work I'll stick with the Evolution Spektrum.

    I'll let you know.

    Thank you,


    What is the right frame rate selection with a Spektrum transmitter and ANALOG servos?

    The Spektrum DX8 offers the 22ms and 11ms options, the latter being suggested for digital servos.

    The Competition SRS offers options ranging from 21ms to 12ms with something more in between... so which one to choose? There is not a lot about it in the manual.

    Thank you,


    Good morning everyone,

    I'm setting up a gas model on a Spektrum DX8 with 4 satellite receivers and I'm using the GEAR channel (#5) to power the ignition on and off from the transmitter.

    For that purpose I use an IBEF circuit which basically uses the receiver batteries to power the ignition (Ignition Battery Eliminating Filter). It works great and I have it on other models as well.

    I assigned the channel 5 to one of the output sockets (N) and although the servo monitor on the DX8 shows that the channel works when I flick the switch, the circuit does not operate at all. To be sure that the circuit is not malfunctioning, I tested it on another receiver and it worked and I also replaced it by a regular servo which does not move when I operate the switch.

    So, the GEAR channel (#5) is plugged into the N socket, the N socket is mapped to channel 5, the GEAR switch on the DX8 is enabled and the servo monitor shows the virtual servo moving BUT nothing happens in the real world, a servo won't move and the IBEF circuit will not switch the ignition on and off.

    I'm a bit lost, I need to fix this to complete the setup and fly the model.

    Thank you for your help,