Servo pulse output

[xygax]

I am about to make a lost model alarm for some lads that havent yet got the hang of the rotary wing. Now there is a little problem with the diference between 35mhz and 2.4G

When the transmitter is turned off on a PPM,PCM system the pervo pulse disapears from the output (really easy to sence) however on a R617FS the signal stays where it was on power fail (except the failsafe channel) i dont have a specktrum or JR but i expect this is the same can anybody put a scope on one for me and let me know. as its a sight harder to manage but still posible (use the failsafe channel and set a value of pulse width to sound alarm) probably throttle kill value and store in eerom on chip. this should react the same to a 2.4G set as no signal on 35...

Thanx in advance

Steve

[Smoothound]

I'd like to help but way over my head Steve

[Andy from Sandy]

When the transmitter is turned off on a PPM,PCM system the servo pulse disappears from the output

For a PCM receiver the output will go to f/s if it can be programmed or it will hold last position.

PPM in some cases can go wild with the servos dancing all over the place.

The output from the 617 is f/s on throttle only all others hold station like a pcm rx does. If you get a 608 and you have something like a 10C or better then you can program failsafe on all channels.

[unwind-protect]

I guess the one thing to do is to plug the alarm into the throttle channel (along with the throttle servo/ esc). Set the failsafe and model alarm trigger to the engine kill value, making dual use of that one channel.

Having said that, unless I'm missing something, it's probably not that common for the signal to be constantly lost after a crash (unless the battery comes loose, in which case you have bigger problems). If you still have the signal then you can trigger the alarm in other ways, say on ch5/ gear sw.