Lost Model Alarm Not Working

[healthyfatboy]

I just put together a few of the lost model alarms on the www.rc-cam.com website and tried them in two different radio systems and neither seems to work at all. The first was on a stock ParkZone Stryker C and whenever I would turn off the radio, it wouldn't ever beep. When I plug the battery in, it gives the normal beeps that it should but then that is it. All three that I built were all wrong.

Also, I tried it in my Spektrum DX7 system. I wasn't really expecting it to work with that as much but it did the normal beeps when the battery was plugged in and then when I shut the radio down, nothing.

Could anyone help me out with this problem? I really would like this alarm on my Stryker since I almost lost it the other day. Thanks!

[MarkusN]

Does your Radio privide a failsafe function? If so, no soap. That function outputs a valid servo impulse, even if the TX is switched off. (the lost model alarms normally operate on the missing servo pulse.) You need an alarm on a free channel that is operated by servo position for those.

[healthyfatboy]

That makes sense. I didn't think my RTF plane had anything like that but I guess it does. Is there any way to disable that on a radio (maybe for certain channels?)

[sxjack]

You need to set the failsafe on the channel that you have the alarm plugged into to 150% so that when the rx failsafes, the LMA sees what it regards as an invalid signal. I have my tx setup so that I can hit a switch and the LMA comes on.

Steve