The MTU-80/40 RF u-Tuning Unit B(80/40 band) addresses noise and intermodulation effects on lower ham bands that can interfere with weak signals. It is part of three modules (MTU-160, MTU-80/40, and MTU-30/20) that can be connected externally without needing internal modifications.

Utilizing large 1.1" (28 mm) Ni-Zn Ferrite cores driven by a precision stepper motor, the RF u-tuning filters achieve a high Q factor of over 300, resulting in a sharp resonance peak near the operating frequency. This system increases the 3rd-order Intercept Point (IP3) by 4 dB, enhancing performance. The ferrite cores are driven by a high-resolution stepper motor with a synchro belt drive lasting over 10,000 hours of operation.

The MTU unit is an option for users of the FT-2000 series, FTDX5000 series, FTDX9000 series, and FT-950. It requires the external µ-tuning base kit when not mounted internally, except for the FTDX9000 series, where internal mounting is possible. The RF u-Tune system can be turned off when changing frequencies, automatically re-centring the u-Tune filter when re-engaged.