Are you on the Simplex Net Map?

Above is the link to an Article about Ham Radio Simplex on the Two Meter Band in the vicinity of Lancaster County, Pennsylvania, United States of America.

Below is a link to a Ham Radio educational website known as the “Ham Radio School” about Simplex, Duplex, and Split.

https://www.hamradioschool.com/post/simplex-duplex-offset-and-split

A Simplex Operation means the radio stations are communicating with each other directly, on the same frequency. Both stations take turns transmitting and receiving on the same frequency with no repeater or other device in between.

Ham Radio School

A Duplex Operation means that a radio station transmits on one frequency and receives on a different frequency.

Ham Radio School

I shall add that Duplex Operations also take place solely on the Two Meter Band.