[Animats]

sci.electronics.design on Usenet is quite helpful. I've been able to get help there with obscure problems in switching power supply design.

Because all the clueless people have dropped Usenet, it's mostly people who know what they're doing. comp.lang.* groups remain useful.

r/electronics is rather lame. Current top articles:

* Join fellow redditors in delivering happiness to one another around the globe! (AD)

* Interesting7805 at the heart of a Super Famicom (SNES).

* Organization Tip: Old Cassette Cases w/ Labels to Keep Parts Sorted!

* Modded Gopro clone sees through Blu-Ray player

* NJ based Components Distributor with NO minimum order quantity (AD)

Not too helpful.

Electronics people usually get Electronic Design magazine. Mechanical engineering people get Machine Design. (Those are free. New Equipment Digest arrives whether you asked for it or not.)