kruser.....Where are you located? I live in the city (southwest side) and get the south tower without an antenna, but I have noticed not a lot of radio traffic goes through that tower with the city's system. (please don't ask me to explain. I might explode) But I have noticed with the north tower an increase in garbled radio traffic especially when city fire is talking. Even some missed "dispatches". For me, that is very unusual. I wonder too if something has changed with the north tower?
I'm very near 141 (Woodsmill now) & Olive on the eastern edge of Chesterfield.
I can pickup the STL City north site really well but the South site can be tricky. It needs a yagi aimed at the tower. I actually use separate yagi's for both sites but for different reasons.
Usually I get the 700 MHz south site including the control channel fairly well but for some reason right now, I can only hear the voice channels but the CC is barely audible. I can hardly tell there is a signal on the CC frequency. The voice channels all come booming in though and I get near perfect decode from them all.
The 700MHz South tower or site never did carry all the cities traffic even all the way back to day one when it came on the air years ago. At first, it only carried the south PD districts like 1 and 2 and I think one other.
Then that site went off the air for over a year, maybe two. It came back as conventional P25 repeaters but was used only for fire and maybe EMS use not long after fire switched over to the P25 radios. Only two of the repeaters could be heard out in my area.
At the same time, they changed the south site's license to a "state license" and removed the original call sign. Not long after all that (couple months maybe), the trunked control channel started broadcasting again.
At that time, I started hearing the south PD districts again as well as fire and EMS but still no North district traffic. I also regained the missing voice channels as it was once again a trunked site.
That seems to be how it is operating right now today even though I cannot hear the control channel. I can still hear all the voice channels and do hear Fire and South PD district chatter just fine but no control channel so I cannot track the site. Lucky for me, the traffic on the site is low so scanning the voice channels only does not cause me to miss much.
For myself, the North site seems to be working normally but it is a simulcast site so you could be getting multipath distortion from the north site.
I also use a yagi for the north site so I can aim at only one tower. That helps me get near perfect decodes from the north site. I can aim at either tower but one of them places the aim directly through Ameren's Creve Coeur tower which is not far from me. Plus some cell towers. The signals from those towers do have an influence of the cities southernmost 800 MHz sites signal and my decode levels drop off some as the Ameren site is used. I find that a yagi aimed slightly north of the Ameren tower gives me the best decode of the cities 800 MHz site even though the signal level is not maximized. The northernmost tower of the 800 MHz system is unreliable for me due to trees, hills and buildings but I can use it for my main signal during the winter months as long as it is not snowing or raining heavily. I think the yagi nulls out the Ameren site being aimed slightly north of the site and that really helps me pull in the cities 800 MHz site.
I use an omni for Ameren and other local non simulcast sites.
Also, any and all traffic that is heard on the cities 700 MHz site is also heard on the 800 MHz site so if you want it all, monitor the 800 MHz north site. I kept expecting them to break up the districts between the two sites when the 700 MHz site came online but that never happened.
I also hear south district cars only on the north site but dispatch will be heard on the south and north sites when they reply to a south district car only heard on the north site. I still think that is because not all cars have radios with the 700 MHz frequencies programmed into them or possibly can't even do 700 MHz at all if they are pretty old radios. Fire was given new radios that can do either. I guess some of the city PD cars may be using radios made before the 700 MHz band was finalized so they could have an 800 range only.