Originally Posted by HeliStyle
could someone explain the brownout problem known with the ar7200bx and how it can be fixed?
Is it a simple fix of needing a better bec ?
All digital receivers have a minimum operating voltage. If the input power drops below that voltage, the receiver must re-boot. Spektrum receivers re-boot fairly quickly, but first you have to wait for the power to come back up, and then if the receiver was off for too long, it has to re-acquire the transmitter signal - this can take significant time. Most of the time with a helicopter you have crashed long before any of that happens and when you walk up to your bird everything will be "working fine"
The supposed "Spektrum brown-out" problem is not unique to Spektrum, but their receivers are a little more sensitive to brief voltage dips, and they have done nothing over the years to fix the problem. YOU can fix the problem though, and I maintain that the "problem" isn't really with the receiver itself, although there are improvements they could make so it would be less sensitive. The preferred way of avoiding the issue is to use a good BEC, but there are also other methods such as a capacitor across the power pins (I forget what size, sorry).
Since the AR7200BX is a digital receiver, it is vulnerable to this problem. Note - I have also experienced this problem (power reset lockout) with a 72MHz digital receiver as well, and it sometimes happens with other 2.4GHz brands. One guy at our club who uses Futaba had a brown-out and he was so upset he wanted his membership dues refunded - said there must be some kind of problem with our field. I spent an hour explaining that to him on the phone, he fixed the problem, he's had a great time at our club ever since.
My point is, you need to use a good BEC, whether it's built in to the ESC or otherwise, and it doesn't matter if you're using Spektrum or any other brand of receiver, if it's digital, you can have power reset lockouts. The knock-off Spek stuff is equally as sensitive as the genuine article.