Antenna fades and lost frames

  • Hi Richard,


    I want to understand the meaning of the numbers from lost frames and antenna fades to make sense whether my model is experiencing alarming losses.


    What do the numbers mean?

    When it says for example 200 lost frames what does that mean? For example when it says 700 antenna fades. I don’t know if that’s extremely bad or that’s normal ? Could you elaborate on this subject please ?


    Thank you

  • Hello,


    Lost frames: both receivers lost the same frame which means a time slot of 14ms in the case of Futaba

    Antenna fades: One of the receivers lost a frame, the PowerBox took the signal from the other receiver


    Your numbers are not good, but also not to bad. Maybe you can change the mounting place from the receiver with the high antenna fades.

  • These are not accurate numbers during a flight. These are just hypothetical examples. I remember last time I flew it the fades and lost frames were in the 100 and I just wanted to get a sense of the scale of these numbers because I couldn’t find any info on them.


    What is normal operating range for both on a dual receiver setup flying a jet?

  • I fly FrSky (same RF chip as Futaba, also SBUS to the powerbox) and i normally see around 20 antenna fades per receiver. A badly placed (near carbon / tanks) receiver goes up to 50 fades. Frame losses in a good setup are 0 or 1 per flight of 7 minutes. 100 fades is still acceptable but lost frames should be well below that.


    My 3 jets with power boxes had about the same numbers of fades so i would consider that as a good baseline (for FrSky at least). With spektrum DSMX i had very similar results.


    Futaba might have a totally different result BUT since both systems use the same RF system and connection to the powerbox i think they are comparable (since my spektrum setup shows the same results also).


    I fly mostly in a open area with no wifi in the area and little cellular coverage so very low interference environment.

  • Hello,


    you cannot compare System A with System B. Many systems do not tell the truth with this values... Some systems do not show the first lost frames on the Digital output. Some hold the old signal for some frames... loosing frames is a normal thing on 2.4GHz, but would totally confuse the users if there are high numbers!

  • Hello,


    for Futaba 200 Antenna fades and 50 Lost frames are o.k.

    But this is just my experience. Depending on the environment on your field it may be lower or higher. For example if many radios are running at the same time - this numbers are higher because of the loosing a frame if a channel is already used.

  • Hello Richard

    I would like also to add my question regarding same issue. My data screenned during ground check ups and setting , usually the information for single Futaba 7008sb reciever is indicated as 0 in the transmitter, however, got one time different data which is includes in the picture, from reviewing previous posts I get this data is quiet poor. My question is:

    1.when exactly the data is fully displayed? I mean, if it is only after a flight or ground check up is measured as well?

    2.What are the normal range should I expect from dual Futaba 7008sb systems?

    * your recommendation for how to correct that? since then I get only 0 on all of them without any changes.

    * what is your personal recommendation way of antenas distribution with dual reciever system ? Currently it involve one reciever on horizontal axis and the teleconverted reciever is on vertical axis , both are 90 degrees to each other of course.


    Thanks in advanced

    Lior

  • Hello,


    the data is alwyas actual. Have a look to the data before you start to avoid using data which maybe counted during power Up process or for other reasons. Check it after landing.

    All values below 400 is fine - from my experience.