On August 4, 2006, XM Satellite Radio began replays of the original 1970s and 1980s AT40 shows with Casey Kasem that were digitally remastered from the original vinyl LPs and open-reel master tapes by Shannon Lynn of Charis Music Group. The event began with a weekend long marathon of original shows, with AT40 then being added as a regular show on two of XM's Decades channels, "The 70s on 7" and "The 80s on 8". With the merger of Sirius Satellite Radio and XM Satellite Radio, these AT40 shows began airing on both services on November 15, 2008. On the 70s on 7, it replaced the 'Satellite Survey', a Top 30 countdown of 1970s hits, produced by Sirius and hosted by Dave Hoeffel. On the 80s on 8, it replaced 'The Big 40' countdown produced by Sirius and hosted by Nina Blackwood. As of October 11, 2009, Sirius XM replaced the AT40 countdown on 80s on 8 and debuted a revised version of 'The Big 40' countdown now co-hosted by three of the five original MTV VJs: Nina Blackwood, Mark Goodman and Alan Hunter (Martha Quinn was a fourth co-host from 2009 to 2015).