If you go to this site
https://skyvector.com/type in KDMW,
then in the tabs at the top click on Washington,
and them zoom in, you should see the VFR chart for Washington area.
121.25 is the automated weather for the KDMW airport and the EMI VORTAC is no co-located as you can see in the chart.
You can see in the picture, the 117.9 EMI VORTAC has a little H in the box, standing for HIWAS. Usually that is just weather, but I imagine since it's the DC area, that is why you are hearing other messages about airspace. That site has the capability to listen on 122.1 for aircraft and transmit voice on 117.9.