SDRplay RSPduo and bias tee

Yes — the RSPduo does include a bias-tee on its Tuner 2 SMA port. (SDRplay)

Here are some details and caveats:

• It provides 4.7 V DC at up to 100 mA to feed an antenna-mounted LNA or active antenna. (SDRplay)
• The bias-tee is software-selectable (i.e. you enable/disable it in the control software). (SDRplay)
• There is overcurrent protection: if more than ~100 mA is drawn, the bias-tee disables itself until reset. (SDRplay)