Just my guess, but there’s an explanation for the difference in quality between the TPX feed and the CNN feed.
Satellite channels and land lines for television transmission are leased, and you have several options for the quality of the channel or line you choose to lease.
I suspect whatever outfit TPX contracted with to handle the feed leased a lower-quality channel for a lower price. Cost is no object for major networks like CNN.
It seems that there is HD, and then there is HD. All HD is NOT created equal.
- JP