Tac channels

Status
Not open for further replies.

paulmohr

Member
Joined
Jul 12, 2017
Messages
171
Location
Adrian MI
When I download the data bases for Lenawee, Jackson, Washtenaw and Wayne I see a lot of channels designated as TAC channels for fire, police and sheriff. What are they and do I need them? I rarely get a hit on any of them and when one does key up it is mostly clicks or a very short transmission, like less than a second. I think about the only one that hits is lenawee fire tac5. Are these useless channels I am scanning for no good reason, or if something major happens will I want them scanning?

Another quick question about FreeScan. What is the RSSI column in the logging window? I assume it is signal strength? With the little stock antenna it averages around 500-600 depending on the channel. After I hooked up my large TV tower antenna the numbers rose to above 1000. Does this mean I doubled my signal strength or is it even an accurate reading? It doesn't seem like I doubled my range, at least not for trunked systems. I still can't get anything other than the local adrian site for trunked systems. Now for analog it does make a difference, I can pick up henry county in ohio, but not very reliable, it is hit and miss.

I live just outside of adrian on East Valley and 52 (right by johnson's gun shop)

Oh, and is there a reason I never hear any activity on the madison, adrian and raisen township channels? Most of what I hear is the sheriff and adrian police. And lenawee fire and ems. I know raisen and adrian township are going on calls, they go by my house all the time. Heck one of them sits in the church parking lot near me sometimes.
 

bprevost

Member
Premium Subscriber
Joined
Feb 4, 2003
Messages
11
I'm not familiar with Lenawee and Jackson county OPS but my guess is the TAC channels are used for tactical or on scene operations. This takes the traffic off the dispatch channel. As an example I know in Washtenaw county (MSPCS 800 system) they have all the INTEROP groups (especially in the fire depts) in addition to FG channels. When a agency is lone responder they probably use the FG channel but if two or more agencies respond (Mutual Aid) they will use the Interop. I remember one fire where they actually used 3 different Interops...1 for fire fighting, 1 for water supply and don't remember the third. They had multiple agencies on that call.

As for the database and the agencies you don't hear it is possible that they are on a frequency that you don't have and is not in the RR database. It is possible a person has not kept up that section of the database for that area. I suggest using the FCC database to look up frequency assignments for those cities/township and put those in. See what you get.

Sorry but I don't know anything about the FreeScan software.
 

KK4JUG

Member
Premium Subscriber
Joined
Dec 13, 2014
Messages
3,162
Location
GA, AL, TX, OK, KS, AR, NC, or MI
bprevost has the right idea. They are tactical channels, frequently in the broadest sense of the word. Depending on the department, they might be used by patrol officers to operate a roadblock, or detectives to serve a warrant and if nothing much is going on, they might use them for any traffic that shouldn't be on the dispatch or other dedicated channels.

Many fire departments use them for on-scene operations. Locally, when personnel are dispatched to a fire involving more than one truck, a battalion chief is also dispatched and almost always immediately moves responding units to a tac channel.
 

paulmohr

Member
Joined
Jul 12, 2017
Messages
171
Location
Adrian MI
Ok so I do want those channels then. If something major happens like a big accident or something those are probably the channels they would switch to. We get two or three major accidents a year right here in front of my house. Not uncommon for city, county and state police to be on scene. Not to mention various ems and fire, including life flight. I thought they were going to land in my backyard once.

I will try the FCC database, thanks for the tip and the help.
 

KK4JUG

Member
Premium Subscriber
Joined
Dec 13, 2014
Messages
3,162
Location
GA, AL, TX, OK, KS, AR, NC, or MI
Maybe they'll use the TAC channels and maybe they won't. It mght depend on how much radio traffic they generate. If other agencies are involved, there's no telling what will happen. Interop channels should be available, if they think of them.

Here in Columbus (GA) the system also has a Safety Tac channel. All public safety agencies (police, fire, sheriff, marshal, etc. have this channel for inter-departmental operations. In addition, there are Special channels (6 of them). They can be for anything. If all the Tac channels are being used, the Special channels are available. The police are present at all high school football games and they often use the Special channels to coordinate their activities. (Different channels for each game.)

But to answer your question, yes, scan them.
 

drdispatch

Old-Timer
Joined
Feb 17, 2007
Messages
765
Location
Fightin' River, Michigan
Something else that no one mentioned yet is that the TAC channels are most likely simplex, so you won't hear traffic if the incident which the channel is being used for is out of range. (An external antenna will obviously affect that. YMMV.) Definitely scan them, 'cuz you just never know.
 

KK4JUG

Member
Premium Subscriber
Joined
Dec 13, 2014
Messages
3,162
Location
GA, AL, TX, OK, KS, AR, NC, or MI
Something else that no one mentioned yet is that the TAC channels are most likely simplex, so you won't hear traffic if the incident which the channel is being used for is out of range. (An external antenna will obviously affect that. YMMV.) Definitely scan them, 'cuz you just never know.
Not always. Locally, the TAC channels are not simplex. However, there are simplex channels available but they are seldom used. In addition, there are "Fail Safe" channels if the system goes down, They are obviously simplex.
 

paulmohr

Member
Joined
Jul 12, 2017
Messages
171
Location
Adrian MI
Yes, last night there was a fire on sandcreek highway. I could follow all the local fire departments until they said they were switching to Tac3. Once they switched I couldn't follow it anymore. And I have the tac channels programmed in. I will have to verify if the frequencies are correct though.
 

SCPD

QRT
Joined
Feb 24, 2001
Messages
0
Location
Virginia
I guarantee they are simplex and you'd have to be close. If your lucky and right distance snd they are using 45 watt or 110 watt mobiles you'd probably hear those ones.
 

paulmohr

Member
Joined
Jul 12, 2017
Messages
171
Location
Adrian MI
I just checked the database and the frequency is correct, 154.4300. It lists 5 tower locations and 5 mobile. Power for the towers says 100 and 45 for the mobile. I have no idea how to tell if it is simplex or not.

So basically you are saying they were probably using the 45 watt mobile units and I just couldn't pick them up from 10 or 15 miles away.
 

SCPD

QRT
Joined
Feb 24, 2001
Messages
0
Location
Virginia
If they were on handhelds (portables) you wouldn't hear unless close, and this will vary on terrain and obstructions along with if it's set to high power, or low power.

Mobiles if 110 watts are used and 45 it will carry further in simplex. But they could be set . Low power or high depending on who programmed it and what they felt was necessary. Most fire departments set tacs in simplex to high but I've seen them low power.

Simplex is one frequency. Transmit and recieve is the same. While some 1 single frequency repeaters exist it isn't a common thing.

The use can be found if it is MO, mobile/portable. RM is repater/mobile. Etc.

The fcc listing will also specify if it is a mobile channel or fixed base etc. While sometimes it can be incorrect snd the users use a repeater on mobile only frequencies, vice versa it usually isn't a thing that is common snd the information is accurate.

I should add some fire departments use repeaters for tacs and have a car to car of that tac frequency also. Sounds like in your case though it is a simplex channel tx/rx.

If they have access to a trunking system one agency can also utilize this if a talkgroup exists for it.
 

bprevost

Member
Premium Subscriber
Joined
Feb 4, 2003
Messages
11
Did some study on this. Like LOSRIO said handheld radio are limited in range and even if the power for frequencies is listed as 45 watts handhelds likely wouldn't be that powerful. The 45 watts is the limit that any mobile unit can be.

Trying some rough mapping you seem to be about 12-15 air miles from where the fire is. A handheld radio on the ground is not going to reach very far. That may be why you see 5 towers for the county so the handhelds can be "heard" from anyplace in the county.

Repeaters use an input frequency that is then repeated on a different output frequency. In looking over county they have a central dispatch on a repeater system. You will hear the mobile units (including handhelds) over a large area. Simplex is just one frequency. Look in the RR database for Lenawee county and you'll see their setup including TAC frequencies. As stated before when you are working a major fire with talk between the local scene people then will usually use a simplex channel as not to block up the dispatch channel. If a call is about an accident the only radio traffic on the dispatch channel will be unit on the way, arrival, calling for ambulance/police, clearing away from the accident and return to station.

Using just the frequencies from the local fire departments in the database may not yield all used frequencies. With the county wide dispatch the frequencies may be licensed to the county and not the local fire agency.
 

SCPD

QRT
Joined
Feb 24, 2001
Messages
0
Location
Virginia
Simplex also lessons the issue of something going wrong in communications. Say a repeater fails goes down etc and you don't need a bunch of guys in a working structure and the repeater fails. Simplex is simple. Localized, 1 less worry and direct to the incident command and as said keeps primary channel clear.
 

paulmohr

Member
Joined
Jul 12, 2017
Messages
171
Location
Adrian MI
So in effect they are reaching the scene and switching simpler lower power hand held like the walki takli's me and my buddies use while hunting on private property. Good for a couple miles or so directly from radio to radio, no repeaters. I am sure there stuff is much better but I believe that is the basic idea you are trying to explain.

So if i really want to hear what was going on I would have had to hop in my car and drive the area where I was close enough to pick them up.Which I am not willing to do, especially at 4 in the morning. Not to mention I have been in a house fire, I have no desire to drive to the sight and what someone dreams, life and memories go up in flames. It sucks, I have been there. I do like to hear how the professionals to their jobs though.

I think I was hearing exactly what are explaining too. I could hear Blissfield coordinating everything, sending out the tones and asking for help from other areas. Then I could hear those areas, like adrian fire responding and letting them know what they were bringing and when they would be there. However once they got there I couldn't hear anymore. Unless they called for additional support.

I also lost a police chase at 3 or so in the morning. It originated in Lenawee and the driver ended up on 23 heading for toledo. Or sheriffs followed him as far as secor rd in syslvania. Then they turned it over to local police and Ohio State and came home. At which point I lost it because I can't get trunked systems from that area. I guess that is just how the scanner world works in this day and age. Why he went to a metro area is beyond me, only increases his odds of getting caught. More radios and possibly aircraft. Once they get an air ship up there are not many places to run.

Thanks for the clarifications, at least I know it is not something wrong with my system. Just a limitation of the current technology.
 

KK4JUG

Member
Premium Subscriber
Joined
Dec 13, 2014
Messages
3,162
Location
GA, AL, TX, OK, KS, AR, NC, or MI
While there are some departments (police & fire) who use simplex Tac channels, not all do. One disadvantage of simplex is that dispatchers can't usually hear what's going on. In addition, larger scenarios or those in and around downtown urban buildings might stretch the limits of simplex.
 

DougG2001

Member
Joined
May 7, 2003
Messages
58
Location
Livonia Mi
Another quick question about FreeScan. What is the RSSI column in the logging window? I assume it is signal strength?
RSSI is signal strength. For freescan I am not to sure about the higher the better. I do know in the cell phone world a high -xxx strength is not good. Example right now I have an RSSI of -117 on LTE band 26, which is low strength
 
Status
Not open for further replies.
Top