[Vk5-wx-sonde] M20

[Bev M Ewen-Smith]

Hi Mark

We are stuck in Portugal this year thanks to Covid-19.  :-(  You seem to 
be in the Lucky Country in more ways than one!

I have had an email from someone in central Europe wanting to decode the 
M20 radiosonde with SondeMonitor.
In the past you have been kind enough to point me in the direction of 
some hints regarding telemetry formats and I wondered if you had any 
information about the M20 format.

It seems to look broadly similar to the M10 with a trigger byte of 0x45 
instead of 0x64 and the following byte 0x20 (M20?), which is the byte 
that distinguishes the M2K2, M10, etc. but the rest of the frame looks 
rather different.

The audio sample the user has sent to me is rather scratchy so I am not 
making a lot of progress working from the binary.

Any suggestions would be very welcome.

Happy New Year to you and we all hope 2021 is better than 2020!

Regards
Bev
COAA