A dual band X-frame wire antenna made using 4 turns for response down to 3 MHz or so, and 2 turns (switched) for response up to around 18 MHz. The loop configurations are tuned using common eBay 365 pF tuning caps.
QO-100 Communications with the LimeSDR Family. LimeSDR can transmit in the expected uplink frequency for QO-100 – which is 2.4GHz – and has a nice reference onboard that makes it relatively stable in frequency aspects
Icom IC-R75 tabletop HF communications receiver came onto the market back in 1999 and was taken out of production in late 2015. Frequency coverage is from 30 hz right to 60 MHz. This allows one to catch the 6 Meter amateur band as well.