Hey John,
Broadcast masks were one of the features that has yet to make it into the Spike software. It is a feature we want to add back in at some point though. I did ensure that Spike can be installed side-by-side with the old software (2.18) in the event you need to use any features that are not in Spike yet. I do apologize for the inconvenience.
I do like the idea of creating a CSV that can dynamically create the limit lines. I can’t offer that at this moment though, but I can point you to the documentation that we used to create the AM/FM masks, http://www.nrscstandards.org/DocumentArchive/NRSC-G201.pdf.
Regards,
A.J.
