Smart-assed Receivers

I got a Berg 4L for the trainer. Part of the mission of this plane is to work on a buddy box for the kids.

Well, one of the features of the Berg 4L is that it characterizes the transmitter that it's supposed to listen to on start up, and after that it ignores other transmitters. It does this by picking out details of the transmitter's frame rate and other timings.

So guess what! With a JR buddy box, it doesn't work! The buddy box system is completely analog -- switching to the buddy box just uses the "master" transmitter's RF deck and antenna with the buddy box's encoders (and frame rate, and timing). So when I switch to the buddy box, the receiver says "Hmm, transmitter changed, I'd better ignore that".

Everything works fine on the receiver that's embedded in my _other_ plane.

So I guess I have to move things around now, or see if the Berg has a "buddy box" setting.

I'm not sure if I should be frustrated that it doesn't do what I want, or pleased that it's so high tech.

Reply to
Tim Wescott
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I'm glad you mentioned this. I fried one of my Bergs and don't know which plane the other one is in but I don't think it's a trainer. mk

Reply to
MJKolodziej

I've since checked the Castle Creations web site. Their FAQ says that _some_ radios will work in trainer mode with the receiver, and others won't (apparently some regenerate their signals). Per CC: "Check with your radio manufacturer, or check your radio".

Reply to
Tim Wescott

Some of the Futaba computer radios use the trainer box output as the stick input and apply the instructor transmitter travel and direction settings to the trainer box output. The output data stream always comes out in the instructor transmitter timing. I used to help out with training nights at a club and this setup made it a lot faster to set a trainer radio up. This setup would work with the Berg.

I don't see what good this fingerprinting could do in an FM receiver. If you have two transmitters on a channel, neither would be reliable enough to do anything useful, even if you ignored the demodulated signal of the unwelcome transmitter. It sounds like an attempt to shine up the consequences of their decoding algorithm design and call it a feature.

BobH

Reply to
BobH

In the case where you get clobbered by the park flyer over the hill it would at least go into no-signal mode, rather than obeying completely incorrect input.

For _some_ planes this could get you close enough to fully capture the receiver again, particularly if the signal clobbering you was intermittent.

Besides, if their DSP is powerful enough and smart enough, they could go a lot farther into the mud to pull a signal out when the two transmitters' signals are roughly equal in strength.

But yea, it's not magic.

Reply to
Tim Wescott

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