“What determines the signal level?”
Power level of the transmitter, height above ground of the antenna, orientation of the antenna type of antenna used, antenna gain (all relate to both yours and the antenna site, distance to and line-of-sight of the xmit site, your receiver, atmospherics (band openings or “skip”, usually a factor on the lower VHF Low band and below). Basically, a lot of variables.
The system you describe is a trunked system. The power levels are the same for any frequency they xmit on, as is the antenna. (They may be using two sites, one for receive and another for xmit, meaning they use two antennas. They may be located at and on the same tower, the same site but spaced apart from each other by feet, or separated by a distance in miles.
If you are having receive issues, you should list the location for us which includes state, COUNTY, town/city, name of system so we can check other factors such as if it’s a simulcast system, your location in respect to the xmit site (do you have line-of-site with the site), distance to the site, geographical lay of the land between you and the site.
