Mercury SRS + Spektrum DSMX and carbon fuselage

  • 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.

  • Yes, those are designed for carbon fuselages. You should make sure the active part of the antenna is fully outside of the fuselage. I would add at least 10mm of the shielded part also. Maybe there is better info on how to mount the antenna's because flat against the fuselage does not work either. If you can hide them in scale antenna's it would be great. Also think about mounting them in the tip of a tail or something if there is no carbon there. You can extend the sat cable to make it work without a problem (as long as you keep the cable away from high current sources like batteries of turbines ect).

  • 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.

  • 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,