Here one can learn about EKKO Stamps in detail:
https://goscf.com/t/10051&whichpage=1Here is an example of the EKKO Reception Stamps:

I recently obtained a "Reception Verified" stamp but is it considered an EKKO or what other group of reception stamps?

It began operations on April 16, 1922 formally as FYI (with prior broadcasting prior to that start date) and became one of the first high-powered "clear channel", Class A stations in the USA. It was the first U.S. station west of Chicago to broadcast at 50,000 watts. It remains on the air today.
Studios are in Burbank, between the Warner Bros. Studios and The Burbank Studios The current transmitter is in La Mirada having first been in the home of its builder, Earle C. Anthony, an electrical engineer graduate of Cornell University who built it on his kitchen table, then a top his car dealership's (Packard) roof. Licensed by the FTC in March 1922 it was assigned the call letters KFI. By day, its signal can be heard throughout Southern California, with city-grade coverage as far as San Diego, Santa Barbara and Tijuana, and secondary coverage as far as Bakersfield and northwestern Mexico, and with a good signal skip can be heard some distance into Nevada and Arizona. At night, it can be heard across much of the western half of North America.
FYI added HD broadcasting but abandoned that format to begin streaming the station in 2015 besides the normal over air broadcasting.
From 1960 to 1973, the station was the radio network flagship station of the Los Angeles Dodgers professional baseball team. Thanks to my grandmother, a Dodgers fan I learned to listen to the games at night when the signal reached the San Francisco Bay Area. Now just to be interesting my grandfather was a SF Giants fan. Both followed baseball when the teams were in New York and maintained their loyalties after the move west. In my immediate family it was mom and me, Go Dodgers and dad Go Giants.
Just an observation but much of early radio was built on kitchen tables, when car ownership was just taking off. As car ownership took off, garages were included with houses. Had garages come around sooner would both radio and the internet (computers) have been developed in garages?
Edit: Disposed of an errant "d."