5 feet Straight up in the air when the plastic piece from the hose tee to the sprinkler head breaks.
Try Melnor customer service. I'm sure you can find a phone number for them on their website. I looked for a number for you on the literature but none is provided.
Yes, it is made in China, unfortunately. Try to find something that isn't these days!
The angle of detection is about 110 degrees. The box shows an icon with the title 360 degrees. That's not the area of detection but the ability to spin it in a full circle, if needed.
Yes. I just did it with the following modifications. First I removed the solar panel and then replaced the batteries with a 3V power adapter and an AC power timer. I cut two red wires inside the unit and re-connected the wire from solar panel input (at the backwall of the unit) to the one for battery power input (on the circuit board). The 3V power thus goes directly to the circuit board through the original solar panel connector at the back of the unit.