trying to receive RF signals sent bij an outdoor weather station sensor

I posted a question on which protocol is used on a weatherstation forum, this is a reply I got:

After some searching, I have determined that the Protocol may be 1.0
or 2.1 protocol. It depends on what series you have. The later
manufactured THR 188, has a 2.1 protocol. It is in any case certainly
not 2.2 or 3.0 protocol.

Looking at the bit rate of 342 Hz it is most likely I have a protocol 1 sensor. I also read in the documentation that the manchester coding is used.