With the help of SM7GYT Gert we built a slave transmitter
That send to SK7RJL on 432,725 MHz.
Built on 2 Motorola Mc Micro
With the two filters used to link along the railway
And a little simple logic.
Output 2 Watts.
Sensitivity -114 dBm after the filter is equivalent to about 0.9 uV.
Works very good.
The antenna for the slave