The E61-433T30D 433MHz 1W UHF transceiver based radio will be available to ship next week on May 7th. The E61-433T30D is advertised for 6Km operating range.
The radio is pre-configured for base or rover operation. A pair of Base Radio and Rover Radio is plug and play without any configuration needed, it sends data from S100 Base receiver USB port to S100 Rover receiver USB port using 115200 baud rate.
One Base Radio can also work with multiple Rover Radios. More on this in the radio user guide.
The radio is similar to what's described in this blog. Customers handy with DIY electronics can also make their own version of the radio following the provided instructions.
While measuring the bundled antenna S11 characteristics, we noticed that adding a metallic plate at base of the antenna seems to improve S11 characteristics by a couple dB, i.e. less signal is reflected, might help improve operating distance performance.
The radio by itself can be ordered here.