Remember the Old Fashioned Ding Dong Door Bell? We Have A Wireless One 150m

Yes simple but really good. You install the waterproof push button at your gate and the receiver Ding Dong plugs into a power point in your house or shed. 

When someone arrives at your gate and they want to let you know they have arrived,  PUSH THE BUTTON and everyone in the house will hear the DING DONG

Attractive, waterproof, simple, and around 150m is possible, and NO WIRES, and only $48 , A Real Bargain

https://gatehousesecurity.com.au/products/door-bell-wireless-up-to-150m