I too would like a clarification of what "No Radar" means. The manual says:

"ADS-B system is reporting that it does not know about radar traffic targets, or that it is
not receiving information from any ADS-B ground station (in this case, you may still see aircraft that
are equipped with 978 MHz ADS-B out devices via the ADS-B receiver). Although you are receiving
ADS-B traffic from other ADS-B equipped aircraft, you are not receiving all detectable traffic because
you are not currently in a radar service volume and ADS-B service volume. Thus, the traffic portrait
may be incomplete. "

My receiver is an AFS ADS-B Dual Band Traffic and Weather Receiver (US only) 74113.

I am seeing some traffic and ADS-B weather, so my assumption is that the receiver is working, I am in a radar service volume and ADS-B service volume (Class C airspace).

Why am I seeing "No Radar" please?