HF mobile activities are a favorite, not requiring the rigors of backpacking portable gear into a location close to nature.  A tent, proximity to the vehicle 12v dc and ac generator power sources, and access to the beverage cooler make for an enjoyable evening or weekend in a "field day" setting.
For SET '05, I assembled this packet system using vintage gear.  The transceiver is an Alinco DJ-160 from about 1989, the laptop is an Ambra from the late '80s, and the TNC is a PK232 from the early '80s.  The vertical antenna is from my 1972 college days.  I did use a new gel cell battery and new digital power meter with power pole connectors.