Redundancy of the radio link.

  • Hi,

    I have tried to gather as much info about the CORE radio as possible to get an overview of the most important and to me most valuable features this new radio may offer at present.

    One thing I have thought about is the redundancy of the radio link.

    On CORE radio it is two independent 2.4 GHz radio links.

    Some questions:

    1. Is both 2.4 GHz radio links in use all the time (if using Powerbox dual independent redundant receiver circuits receivers)?
    Or is only one of the two 2.4 GHz radio links in use, and if it fail the other jumps in automatically?
    2. The CORE radio has no backup radio link on another frequency (like on 900 MHz).
    So if both 2.4 GHz radio links would fail there is no backup radio link to save the siutuation.

    What is Powerbox Systems thoughts around this situation and why a backup radio link on another frequency has not been

    implemented in the CORE radio?



  • Hello,

    both transmitters in the CORE are working 50/50. In the receiver both seperate radio parts are listening both together. So if one receiver antenna has no signal, the other one is taken- no loss of frames like other systems with only two antennas switching 50/50 in the receiver.

    We do not need 900MHz - only systems with a poor 2.4G quality need that. We have over 9km range and a bullet proof transmission regarding interference. This things are not given from the competitiors, so they are selling it as a backup - people pay for it.

    Nevertheless: we have space in the antenna area to implement a 3rd radio part for future developements.

  • ...

    2. The CORE radio has no backup radio link on another frequency (like on 900 MHz).
    So if both 2.4 GHz radio links would fail there is no backup radio link to save the siutuation.

    What is Powerbox Systems thoughts around this situation and why a backup radio link on another frequency has not been

    implemented in the CORE radio?


    Users using this "feature" have more trouble than good. In the case of Jeti, most users have never installed the 900Mhz receiver or, after some experience, removed it.

  • Hi,

    Many thanks for the fast answer.

    Some additonal questions below (no hurry to answer) regarding the most fundamental of a radio,
    the radio link, in this case the CORE radio.

    I use at present a Futaba 14MZ and it has a single FASST 2.4 GHz radio link.
    It has been rock solid for me since the Futaba TM-14 2.4 GHz external plugin module and
    Futaba FASST receivers started to come out for this radio over 10 years ago.
    It is a good thing that the CORE radio has dual independent 2.4 GHz radio links.
    The majority of radio manufacturer rely solely on 2.4 GHz frequency for the radio link today
    (single or dual link) so I see personally not a problem really that a high end radio like CORE
    do not have a backup radio link on another frequency.

    Some additional questions:

    1. What is the more common known radio link interference sources today that could
    lead to severe interferance or even blocked 2.4 GHz signal, so even a Powerbox CORE

    dual independent 2.4 GHZ radio link could be taken down?
    Is it in extreme environment like extremely many other 2.4 GHz transmitting sources in vicinity

    or very strong transmitting 2.4 GHz sources in vicinity that is the real danger?

    In other words what situations should be avoided to fly with a 2.4 GHz radio, even with

    a dual independent 2.4 GHz radio link like CORE radio use?

    2. Does the CORE spread spectrum work in some unique way compared other common spread spectrum

    RC systems, that should make the CORE more robust against interferance?

    3. How many hopping frequency channels in the 2.4 GHz band is used and how many hops per second

    is used for the CORE radio?

    Is the same spread spektrum used in CORE that was used in Weatronic radios before, that was described in

    Weatronic receiver manual:

    "Weatronic systems use 81 channels spaced at 1 MHz and both transmitter and receiver hop within these channels 100 times per second following a random pattern which is individually set to each transmitter/receiver pairing. This sequence is communicated analogically between the transmitter and the receiver and is therefore only known to transmitters and receivers which have been bonded together. If an interference is experienced on any channel, such channel is excluded from use until it becomes clear again. This system is called adaptive FHSS and is unique to Weatronic systems. The use of adaptive FHSS ensures that minimum interference is caused to other users of this band and enables maximum use of the available frequency spectrum. It also significantly enhances the reliability of the frequency hopping scheme used"

    (page 8, 4.1. General system philosophy.)

    Thanks for Your time,


  • Hello,

    1. If somebody blockes the complete 2.4GHz spammer with very high output power. But even in this case it can cuse problems only if you come with your model closer to this jammer.

    2. We use another modulation type, I don´t want to make all thi sknowledge official.

    3. Yes the radio link parameter are the same than the old Weatronic - but your text below is an older version. Our bandwith is different as it was with the latest Weatronic radios.

  • Hi,

    1. How many Powerbox Systems receivers can be used for radio link redundancy with the CORE radio?
    a) When PowerBox "powersupply system" is in use (like Royal SRS etc)? Assuming use of PBR-26D receiver in this scenario.

    b) When no PowerBox powersupply system is used?

    2. Can two Powerbox receivers be linked together for more receiver channels for example two PBR-9D, one for ch 1-9 and the second spanning for additonal ch 10-18? If one need to use the servo connectors 1-9 on both the receiver (not using P²BUS in this scenario).

    3. If one want to use P²BUS to connect servos (when MKS servos has support for that) and receiver(s) and want to use several receivers for redundancy (not spanning for more channels) - is this possible and how many receivers can be used for reduncancy?

    To compare: Jeti can when their Central Box is used (with Jeti DC/DS-24 transmitter) have 3 receivers connected (two 2.4 Ghz Rsat 2 and one 900 MHz Rsat receiver).


  • Hello,

    1. You can bind up to 4 receivers. Also 4 different receivers are possible. (for example 2x PBR-7S + 2x PBR-9D)

    a) Yes

    b) Any

    2. You will be able to link 2x PBR9D and then have 1-9 and 10-18. This will come later.

    3. A better option is to use the PowerExpander and 2x PBR-26D. Then the system is redundant

    As written above: we really don´t need a 900MHz option as our 2.4 link is super robust!