How to check that your TV antenna is properly connected

In our Fuzion 429, we have always had problems with our TVs not finding channels. Early in our ownership of the RV, a dealership had replaced our original antenna with a Winegard 360. Of course, we assumed they checked it out properly. When I had told them we were not getting channels, they told me the antenna was working just fine.

Frustrated with this, and not wanting to spend even more time at a dealership, we had been periodically using an inexpensive window-style flat HD TV antenna you might by at a store. That worked just fine but was a bit ugly. Many campgrounds have cable and, realistically, we don't watch that much TV.

Finally, we decided to take a look at the KeyTV junction box to see if it was properly connected, do some diagnosing, etc. Turns out, the coax coming from the antenna was NOT EVEN CONNECTED.