rcjets_63

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Hi Chris,

I haven't set up the receiver pair yet today (as promised) but plan on doing it later tonight so stay tuned for the step-by-step instructions which I'll post later. In the mean time, I wanted to comment on your post.

You mention that the satellite receiver doesn't control any functions. I think that what you meant by that is that there aren't any servos plugged into the satellite receiver. That is true, but the satellite receiver still is functioning and is important to the system as the satellite provides:
- antenna diversity; and
- receiver redundancy.

Adding the satellite receiver now gives you a total of four receiver antennas (two on the primary receiver and two on the satellite). You can arrange the four antennas at different locations & orientations to improve the likelihood that the signals sent out by the transmitter modules will successfully be seen by an antenna on a receiver regardless of the orientation of the plane in flight (where perhaps one/more antennas are blocked by the turbine, fuel, batteries, etc)

Adding the satellite receiver also gives receiver redundancy. A receiver isn't just a device that drives servos. Think of a receiver as having several sub-systems as follows:
1) an RF module that picks up radio signals and converts them into electrical pulses
2) a de-multiplexer that takes the electrical pulses and splits them up into the individual signals for each channel and sends the signals out to each servo port. It can also combine the signals into a PPM command stream which it can send to the servo port designated for sending out PPM data;
3) a power distribution system that provides battery power to the internal components of the receiver and to the servo ports to power the servos;
4) a mechanical system consisting of the board(s) and the servo and EXT ports; and
5) a variety of other sub-systems that aren't relevant to this particular conversation.

While the satellite receiver doesn't have any servos connected, it still is receiving the RF signal, converting it to a PPM stream, outputting the stream to the PPM port where is can be used, as required, by the primary receiver. That is the redundancy and the PPM signal from the satellite can be used by the primary receiver in the case where there is a failure in the primary receiver.

Let's look at potential things that could happen to prevent a receiver from functioning....
1) Signal loss: at a particular orientation of the plane, the turbine is directly between the receiver antenna(s) and the transmitter or a receiver antenna(s) is pointing directly towards the transmitter. This is the most likely scenario. If the primary receiver isn't getting a signal from it's antennas, it will look at the PPM stream from the satellite antenna (which likely will not have it's antennas blocked or pointed at the transmitter at that instant in time). This is why we spread out the antennas and put them at different orientations. The primary receiver will take the PPM stream from the satellite, and will process the stream and send commands to the servos (which are plugged into to the primary receiver)..
2) Failure of the RF module in the primary receiver; this is a much less likely scenario but, if it happened, the PPM stream from the satellite would used to provide command info to the servos.
3) Failure of any other sub-system in the receiver, a battery failure, a short circuit that "smokes" the entire receiver, etc. Assuming that you don't abuse your system, use high quality components with proper isolation, etc, this is also unlikely as the components are high quality and tested, etc. Still, it can happen, which is why the Dual Path - Dual Receivers - Independent configuration exists (see post # 211) where the servos are split between receivers.

Which brings us back to the question of why use the satellite receiver as a clone? Compare the pros/cons having the satellite receiver in clone mode (see post #208) and the pros/cons of having the satellite in normal mode (see post #209). What #208 clone "pro" do you find particularly appealing that you are prepared to go to the extra setup effort? Dave and I really like being able to see the signal strength on all four antennas (#209 normal "pro") so having the satellite in normal mode (#209) is the configuration we use.

Regards,

Jim