HHFW RF power delivered to the core plasma of NSTX is strongly reduced as the launched wavelength is increased—for BΦ = 4.5 kG, heating is ∼1/2 as effective at kφ = −7 m−1 as at 14 m−1 and ∼1/10 as effective at −3 m−1. Measured edge ion heating, attributable to parametric decay (PDI), increases with wavelength but not fast enough to account for the observed power loss. Surface fast waves (FW) may enhance both PDI and also losses in sheaths and structures around the machine—FW fields propagate closer to the wall with decreasing BΦ and k∥ (onset ne∝BΦ×k∥2). A dramatic increase in core heating efficiency is observed at −7 m−1 when BΦ is increased to 5.5 kG—central Te near 4 keV at PRF = 2 MW. Also, the PDI losses are a weak function of BΦ and k∥, whereas the far‐field RF poloidal magnetic field (at 5.5 kG) increases a factor of ∼3 when k∥ is reduced from 14 m−1 to −3 m−1, suggesting a large increase in wall/sheath power loss and a major effect of surface fast waves on edge losses.