Just getting into to R/C . Read lots and lots and lots for this 6o yr old brain.. All instruction i read about connecting batterys and tx say turn tx on first then connect battery., disconnect battery turn off tx. Why?? Just curious

If you turn on the Rx before the Tx then the Rx is free to do whatever it wants to which includes the possibility of starting the motor. And a spinning prop right next to, or against your arm is the last thing you want. It could also respond to someone else's transmitter that might be on at the same time.

However, if you turn on your Tx first, making sure the throttle stick is down (off), then when you plug in the Rx it will only respond to your Tx and nothing bad should happen.

Also, there are digital Rx's that lock to your Tx. Some will go into a lockout condition if they don't see a good signal at power up.

Dave

O.K. that makes since. Thanks