u/the___chemist

In Germany, helicopter training flights of the german federal police are conducted to detect radioactive ground contamination. What kind of measuring instruments are used for this? Don't the detectors have to be incredibly sensitive to pick up a sufficient signal from a significant altitude (given the inverse-square law)?

Is this only for mayor accidents or also for counter-terrorism purposes?

Hello, I need your help repairing a remote control.

My wife needs it for children's birthday parties at her daycare and is very attached to it.

The remote is constantly sending an "on" signal, and both the status LED and the IR LED are blinking continuously. It doesn't matter whether the "on" button is pressed or not. However, if the "off" button is pressed, the blinking stops. I've found with a multimeter that both buttons only have continuity when pressed. However, there's 2.3V at the "on" button as soon as batteries are inserted. Is a pull-up or pull-down resistor faulty? The resistors R1-R3 look a bit suspicious to me.

Do you have any ideas on how I can repair it?

Thank you in advance!