There's always the 3D Hobby Shop podcast, but that's obviously mostly related to 3DHS planes. There is often technical information in there as well...and I try to make it funny here and there.
Also look through the old episodes of ATTF if you haven't already. It was mostly plane stuff for the few years I was part of the ownership. However, ATTF was more like a few hosts that were learning as they went...so if you listen from the beginning episodes...you'll hear how we learned as time went on. Lucien Miller from Innov8ive Designs was a regular (runs it now) and there are MANY technical questions he's answered over the years...however it's mainly about electronics. Not only motor/esc stuff but a LOT of servo stuff as well.
Also check out the RC Today Show...it's a great show however almost nothing Giant Scale from the main hosts...however they have a lot of cool guests...but you'll have to also sit through Heli and multi-rotor talk as well.
There really isn't much more. The CrashCast is great if you're into scratch building smaller stuff and the obscure (read:cool, old school, yester-year building techincs) parts of the hobby, FliteTest is for the FliteTest crowd.
The AirShow Network is pretty much a LHS promoting your typical Hobby-Town-ish LHS wares. (however, they do a great job with current aviation events and news. (AMA stuff, full-scale, etc) You can go back and find an awesome interview with Chris Hinson of EF)
If you're bored, look up the old episodes of The Right Stick...there are only a few but they're pretty good and you can hear some old Scott Stoops and Ben Fisher interviews.
