what other good engineering forums are out there?

Curious, a lot of the forum I had used in the past are drying up--no conversations. Any good active forums on microwaves, communications, radar, medical microwave, electromagnetic simulation, etc?

The RF forums on LinkedIn have some activity, but EDAboard is much more active.

When I do an internet search of electronics terms, the list often has an Edaboard thread or two among the first few hits.

Other message boards might be in the list too, but not so often.