Posts by grecchia

    As a follow-on question, I noticed that the trim value changes quite a bit going through the PowerBox, even with the new replacement, fresh from the factory. For example, I set rudder trim and sub-trim to zero in my transmitter. With tester connected directly to Ch 4 of the R7008SB receiver, I read 1522 microseconds. With the same receiver connected to the Competition SRS, via S-Bus and with Ch 4 mapped to Output C, I read on (C1) 1490 microseconds, a noticeable difference in the rudder deflection.

    Is this the normal operation of the PowerBox?

    This is just a simple thread to point out a solved telemetry issue in a previous thread, which was labeled "Trim instability issue". After the trim issue was resolved, the earlier thread also covered a separate issue about Telemetry.

    Since the Manual (at least the version I received) does not document this Telemetry setting in the Menu, it is worth pointing it out separately, in case other pilots may be struggling with it, as I did:).

    Problem solved! It was the "Telemetry" point in the "RX/TX Settings" menu, not documented in the Manual and now under the Teach Failsafe point. I believe it was not there in the V.24 version (but I am not positive). When I updated the old PowerBox to V.25, it must have defaulted to "Futaba", a reasonable choice since the "TX-System" menu point was set to S-Bus (which is only Futaba). Once I change "Telemetry" to Futaba, it all started working immediately. It does seem a bit redundant, given I had already chosen S-bus above.

    I'd recommend updating the Manual, if it has not already been done.

    In any case, I should not have missed it.

    Thank you very much for the quick response and your help....

    I contacted PowerBox Americas and, while the old unit will be sent to Germany for repair, I was able to buy a brand new Competition SRS unit (V.25), which I installed today. The good news is the trim problem is no longer there and initially it seemed the new unit worked normally. However, the bad news is that I can no longer get the PowerBox information (Voltage, Capacities, RX info) via Telemetry (Futaba 18MZ and two R7003SB receivers). The other sensors' telemetry (receiver voltage, temperature and RPM) work fine. I tried to re-register the Teleconverter and also Reloaded the slot numbers of all sensors, directly connecting to the Transmitter port. No luck!

    I reconnected the old PowerBox unit to the same Teleconverter and receivers and its Telemetry worked fine.

    I am now out of troubleshooting ideas. What am I missing? Please help. Thanks


    if it were a temperature-related problem, wouldn't the trim move in the same direction, not back and forth with power cycles, as the internal temperature of the PowerBox increases, possibly due to heat generated by the voltage regulators?

    Regardless, it would seem there is a malfunction of my PowerBox. What do you recommend at this point?

    Driven by my PowerBox Competition SRS (V.25), the servos (MKS-HBL380) consistently power up with minor, but noticeable changes of trim. For example, through multiple power cycles, the rudder’s master servo comes up, seemingly at random, in one of two different, but very repeatable, positions. For one position, I need to give a +12 value of sub-trim in the Futaba T18MZ transmitter to bring the rudder to exactly neutral. The other position requires +18. However, if I power cycle the servo directly plugged into the PWM port of the R7008SB receiver, it consistently comes up at the same exact position, requiring a sub-trim of -35. The plane and its PowerBox are about 2 year old, but I noticed this issue only in the last few weeks of flying. I also noticed the servo movement is somewhat jerky when connected to the PowerBox, but smooth when connected directly to the receiver. Are these symptoms indicative of a problem with my PowerBox device?

    I just installed a few telemetry sensors, including a GPS-II, in my 40% aerobatic plane, which uses a Futaba radio and a PowerBox Competition SRS. As a quick background, the GPS-II and the transmitter, a Futaba 18MZ-WC, were recently obtained from another pilot, who previously used a PowerBox Royal directly connected to the GPS-II. In my plane, because it uses a Competition SRS, I had to connect the GPS-II as a regular Futaba sensor, connected to the SBUS-2 of the primary receiver (a R7003-SB). For that reason, I used the Terminal program to set the GPS-II to SBUS-2 mode of operation.

    The PowerBox and the GPS-II (as GPS-1675) were already listed (registered?) in the 18MZ, when I set up telemetry in my plane. Now the Temperature sensor and the magnetic RPM sensor (both Futaba components, assigned to their default slots) work normally and provide credible telemetry data. The PowerBox (connected via the Teleconverter to the SBUS-2) also provides good data, starting at slot 8, in the first 8 slots (voltage and capacity of the two flight batteries, and radio performance parameters), and empty values in the next four slots, possibly associated to a connected GPS. However, the GPS-II , set to start at slot 24, gives out data totally inaccurate (for example, 15,000 ft altitude and only 97 yard distance after a 10 minute flight).

    By the way, the GPS-II seems to be able to lock on the satellites, as indicated by its green LED which becomes steady after a short period of blinking.

    What, if any, additional or different steps do I need to take, to make the GPS-II work correctly in my environment?

    Since it appears the last few posts are still relevant to the thread I started in English, can anyone please summarize their contents in English?

    In general, it would seem considerate to stay with the language the thread started....

    Also, can Richard please indicate if it is normal to have a few Lost Frames (not Holds) during a 10-minute flight?

    My Futaba Transmitter T14SG was updated in May to Ver 7.0, which still appears to be the latest, from what I can tell on the Futaba web site.

    I flew the plane today three times and I can confirm that, after each flight (about 10 minutes long), both Powerbox and the Transmitter telemetry screen were reporting the same number of Antenna Fades, about 40-70 for each receiver. However, Powerbox reported only a very small number of Lost Frames (1-3) and zero Holds. These two numbers were consistently reversed in the Transmitter telemetry screen (that is zero Lost Frames and 1-3 Holds).

    As you already indicated, it does appear there is an error in either the Futaba telemetry or the way PowerBox reports the parameter values to the telemetry, by which the two numbers (Lost Frames and Holds) are reversed.

    At least it appears there is no big issue with my plane's control link. I assume the small number of Lost Frames is normal and acceptable. Correct?

    I suggest that PowerBox work with Futaba to correct this error, where ever it resides, and verify that other Futaba transmitters don't suffer from the same issue.

    Thanks for the reply. There are really two remotely-reported values that seem out of order and inconsistent with what is reported by the Powerbox on its screen, the Lost Frames and the Holds. Will you/your people be checking the Teleconverter (I assume its firmware) for errors, or do I need to do anything on my end?

    I did a bit of experimenting today, with the plane on the ground (i.e. not flying). Both receivers were connected via a modified extension that allowed me to interrupt the signal lead on the S-Bus to the PowerBox. The first picture shows the RF-Flight Recorder screen with both receivers connected normally. I then interrupted the signal lead for Receiver 2 serial bus. The Antenna Fades on RX4 started incrementing rapidly, as expected. Reconnected Receiver 2 and interrupted only the signal lead for Receiver 1 serial bus (power and ground and the SBus2 telemetry link were still connected) and I could see the same parameters on the Transmitter screen (Telemetry Monitor). Now RX1 Antenna Fades were incrementing. Then I disconnected the signal leads of the serial bus for both receivers. On the Powerbox screen I could see both Antenna Fades and Lost Frames incrementing quickly, with one Hold reported. However the Transmitter display froze. It restarted again only after I reconnected the signal leads. Powerbox continued reporting correctly (Picture 2), but the Transmitter refreshed only the Antenna Fades, not Lost Frames and Holds, which remained stuck at the odd numbers shown in picture 3 (no Lost Frames and 255 Holds!).

    I now start wondering if what I had noticed before beginning this thread (that is, more Holds than Lost Frames being reported) was indeed related to some bug of the Futaba system and its telemetry link and makes me loose confidence in its reporting.

    Your thoughts? Is there possibly a safety problem in the control link of my plane or is it just a telemetry issue?

    In the meantime, please clarify the relationship between "data packets" and "Frames". Also, is the "Lost Frames" count, as reported by the PowerBox, associated with a specific receiver (out of the two installed), or is it a combined count, or perhaps indicative of both receivers being simultaneously unable to provide a data packet to the PowerBox, for a period of time shorter than a Hold? I would like to better understand the definitions for these RF parameters, as the PowerBox manual is somewhat unclear on this subject. Is there any better document that I can access?

    That is exactly what I thought and why I was so puzzled by a Holds count higher than the Lost Frames count! I wonder if there is some firmware bug, either in the Radio or the PowerBox, by which the two counts are reversed. Regardless, both counts were non-zero and this is a concern to me. Next time I fly this plane, I will take a picture of the screen and send it to you.

    I did not feel any Hold, but it may have been brief enough to go unnoticed. The number of Fades were different for each receiver. The Lost Frames number is not associated with a specific receiver, at least in my radio system, and in the RF-Flight Recorder screen of the PowerBox. There is just one count for it and, if I remember well, it was not very large, actually smaller than the number of Holds, which was 8 in one flight.

    I have a new Competition SRS installed in a new 40% IMAC plane, with two Futaba R7003SB receivers connected to RX1 and RX4 ports via SBus and telemetry enabled (SBus2 on Receiver1). The plane (about 20 flights so far) is not showing any abnormal radio behavior, however yesterday I checked for the first time the RF parameters via telemetry on my Transmitter (Futaba T14SG) and noticed a number of Fades on both receivers (probably normal), a few Lost Frames and a number of Holds (8), actually larger than the Lost Frames. Because of the Holds, I am concerned about the safety of my setup. Is this a sign of poor radio link and what should I do, if anything, to correct it?