This signal type (Amplitude Modulation) is what is used by the Petsafe systems.

Cost effectiveness - you wont beat this brand.

You may however have some compatibility issues with some brands of robotic mowers. That said, Petsafe is incredibly cost effective and available on the retail market.

They used to have a professional range available through the dealerships, this is no longer the case. All the kit is available retail - buy it from a dealership and your pay more unnecessarily!

If you hunt about online there are some bargains to be had occasionally. As they have been selling retail for so many years.