I could see him taking on both the "droopy" voice for TBS and this "oldies radio DJ" voice for his own show - there are reasonable similarities, at least to my ear.
The first time or two I heard Spike call in I thought he was a "dungeon master" in the sense of D&D. Or was it PFT or someone who thought that? Maybe both. I used to fall asleep on airplanes to TBS (because it makes me relax, not because it's boring), so I have all of these weird half-memories of the show. The whole Power Pop Pop-Pop saga in particular is like a dream to me.