Hi mark,
Thanks for your quick reply.
Signal strength: No need to buy a new antenna. Good 
The SIM is working fine in a smartphone and a laptop. PIN request is disabled.
APN information is given by Deutsche Telekom. I’ll check for typos.
The connection script is called “pap” because Deutsche Telekom uses PAP for authentication. If I understood it right, this file should be used in this case?
“noauth”: should this information be placed in the connection script rather than in the provider file?
With the default install routine and the generated/modified script I got an error, but I’ll check this setting again.
Thanks again and best
Mat