There was an advisory put out about the DX7 receivers needing specific power levels lest they reboot in flight.

There was a firmware update that is supposed to decrease the boot time so that there is less chance of a crash if this happens.

Apparently 4.8v and even 6.0v battery pack voltage output can drop low enough because of momentary servo draw so that the RX reboots.

Apparently Spektrum now sells a small capacitor to keep the RX charged up during a voltage drop... it is something very similiar to this...

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