After being out of the area for a number of years I happened to be driving on Hwy99 through Lynnwood yesterday. One thing that stuck out of place like a sore thumb was a large HF antenna mounted to a cell tower monopole (
located here). Sorry I did not have time for a photo but it appeared to be a yagi configuration with folded elements. Bear in mind I had all of about a second to look at it.
Anyhow this was too far out of place to be ignored so down the rabbit hole I went. Experimental callsign WJ2XXI licensed to "Western Maritime Broadcast LLC" and "10Band LLC" on a variety of HF frequencies from 4mhz-22mhz at 10kW. I figured it was likely some sort of maritime data/email coast station (of which there are plenty up and down the coast) however after further research 10Band LLC appears to be this:
https://sniperinmahwah.wordpress.com/2018/06/07/shortwave-trading-part-ii-faq-and-other-chicago-area-sites/ Its an interesting read. For quite some time I've been aware of fiber and microwave paths dedicated for this purpose but had no idea shortwave was brought into the mix.