Some Detroit site signals break up

Status
Not open for further replies.

dnoyeb

Member
Joined
Apr 20, 2010
Messages
89
Location
Southfield, Michigan
I am wondering why I hear some of the signals from Wayne county loud and clear, and others break up terribly. Yet the person they are speaking with seems to hear them fine.

This seems to imply the audio I hear is coming from the given radio, and not from the tower itself. is that true? Does the tower not repeat the audio for all to hear? Or does the tower just instruct on which frequency the group should listen, but itself does not broadcast the audio?
 

Citywide173

Member
Premium Subscriber
Joined
Feb 18, 2005
Messages
1,871
Location
Attleboro, MA
I'm going to assume that you are physically outside the City of Detroit, trying to listen to Detroit talkgroups.

The Detroit system is very unique, in that the majority of the repeater sites are on the outskirts of the city, and pointed in toward the center with directional antennas....at least this is how it was explained to me. The reasoning, again as explained to me, was to avoid interference on co-allocated frequencies in the neighboring sections of Canada.

Basically, they designed a system that works in the City, on the lowest power possible to provide coverage, which is the way that every system should be designed, but thankfully for those monitoring, the systems usually have more power than necessary, and can be monitored for a greater distance than necessary for adequate coverage.

You are not hearing the radios on the input frequencies (unless you're monitoring 45 mhz below the published frequencies, and even then I'm not sure a P25 radio would decode a trunked system properly), you're just hearing a weak signal.
 

dnoyeb

Member
Joined
Apr 20, 2010
Messages
89
Location
Southfield, Michigan
OK, that's very helpful. I am actually about 1/2 mi from the Southfield/Oakland County tower. So I am indeed on the outside of the city. I am 1 mile outside of Detroit. I get OK reception. Probably much better if I had a real antenna instead of the handheld.

So it sounds like Detroit does not have just 1 antenna like the database shows, but several antennas pointed inward?

Anyway, I think I'm getting the hang of this.
 

gpp10x

Member
Premium Subscriber
Joined
Jan 18, 2003
Messages
461
Location
MI
I forget the exact number but there are 10 or 12 tower sites that broadcast (simulcast) the same radio transmissions thru out the city.
 

gpp10x

Member
Premium Subscriber
Joined
Jan 18, 2003
Messages
461
Location
MI
Last edited:

dnoyeb

Member
Joined
Apr 20, 2010
Messages
89
Location
Southfield, Michigan
Fascinating! I guess simulcast site means multiple antennas? I found the one closest to me. I used to live 1/2 mile away from that. Its interesting to finally know what these towers are for. This tower (#6) is on Grand River, right inside the Fire Department station. The Police station is right behind it as well. Sadly, that police station is closed. Along with the high school right in front of it... I bet the fire station is not closed since the tower is there.

I'm going to drive over there and see what I can pick up.
 

gpp10x

Member
Premium Subscriber
Joined
Jan 18, 2003
Messages
461
Location
MI
Even if DFD closed the fire station the antenna tower would remain. If you are in close proximity to that antenna site you should have terrific reception. Also be sure to read the 2 wiki links posted here if you haven't done so. It will help explain things.
 
Last edited:

dnoyeb

Member
Joined
Apr 20, 2010
Messages
89
Location
Southfield, Michigan
Yes I read the wikis.
If the fire station closed there would be trouble protecting the tower.
Anyway, I get very choppy reception in the city.much better outside of it. Hope I can figure something out. Seems like a mobil scanner will be tough in Detroit
 

dnoyeb

Member
Joined
Apr 20, 2010
Messages
89
Location
Southfield, Michigan
The FD has no responsibility in protecting or maintaining the radio towers.
I doubt if anyone will mess with the tower being next to a station that is manned 24-7. Next to an abandoned station is another story. So I would expect there to have been some consideration. The most unprotected area in the city has to be the location of former police stations.
 

Rexem

Member
Premium Subscriber
Joined
Oct 22, 2005
Messages
36
Location
Region 2N (SE Mich.)
Detroits system is kind of funny sometimes. I was sitting outside of the communications building and Detroit EMS was still breaking up every so often.
 

dman9377

Member
Joined
Jun 2, 2010
Messages
18
Location
michigan
iam 1/2 mile from tower on grand river and my scanner is choppy 24/7 any suggestion to get better reception
 
Status
Not open for further replies.
Top