I'm not sure if you can get these as podcasts, but here are the two sources that help me most often with my understanding:
1. Watch the SRF Tagesschau (news) every night. The anchors speak high German but most of the interviews are done in Swiss German. It helps with the context of what's being said. Also the weather is always done in SG.
2. Watch the program called Arena on Friday nights on SRF. It's a round-table discussion, almost completely in Swiss German, about current hot topics.
If you're like me, you'll pick up just enough Swiss German to start muddling your speaking of High German when you're out and about.