Ross Archer wrote:

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* Yaesu FT-857D mobile HF transceiver (with full general-coverage).

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Ignition noise is a problem at higher engine RPMs. It limits the
usefulness of hamming but doesn't affect SWL as much due to the
generally stronger signals.

Looking at the brochure I see it has a variety of DSP options; does
yours have adaptive noise cancellation? Properly implemented,
adaptive noise cancellation algorithms reportedly handle periodic
noise like ignition whine quite well.

Regards,

Michael