Pecuniary rules apply to operating radio services using amateur radio for business. It doesn't mean you are restricted from profiting from create equipment, tools, or training.
You can absolutely talk about these interests, your business, or your work building things (e.g. antennas) for the ham market. You just can't conduct business, such as hopping on 80M and advertising a sale on antennas, or taking payment for communications between parties, for example.
