Ok, let me answer my own question.
I first looked for a more clear station. Put it on that. The picture improved markedly, but the audio didn't. Then I thought about how I have it hooked up...
The system is hooked up through a Yamaha 2095 receiver using the second zone. I'd never even looked at the zone 2 remote, but sure enough, there's a volume control. Pumped up the volume a bit, and I'm set.
Pretty cool. Picture is very good, in fact crystal clear. I'd highly recommend the ChannelPlus 3025!