PHY: In 10BT mode differential output voltage harmonics requirement not fulfilled

IEEE802.3 states for 10BASE-T in clause Differential output voltage:

The peak differential voltage on the TD circuit when terminated with a 100 Ω resistive load shall be between 2.2 V and 2.8 V for all data sequences for a type 10BASE-T MAU ... When the DO circuit is driven by an all-ones Manchester-encoded signal, any harmonic measured on the TD circuit shall be at least 27 dB below the fundamental.

Due to technical reasons the differential output voltage harmonics are below 27 dB.