MARCS for dummies? (specificly post 7)

[Mylan]

OK, Post 7 still frequently uses their low band; They also often use the Belmont County TRS in which they have their own talkgroup....... My question is this: Since I dont understand this MARCS thing all too well... Do they utilize that system also and if they do, what should I be hearing on which site... the same thing? For example, lets take the following fairly close together sites:... Bridgeport, St Clairsville, Powhatan Point, Clarington, and Beallsville... they are all within 25 miles of each other... Will the same traffic be heard on all 5 of those sites simotaniously or does each system need to be independently programmed?..... Who or what determines what gets brodcast on which site if they dont brodcast the same thing at the same time... How does this thing work?.... I mean should I be able to hear all of district 7?... should I be able to hear other districts as well?... should I be able to pick up any LEERN talkgroups??? mutuial aid? emergency response? Please help 'cause I am very stumped here......

Also when I do recieve some traffic on a local MARCS site, it seems like the mobile units are understandable but something is very annoyingly encrypted... could this be the post radio or is this something else....or do you know.... it is not as annoying as a digital trasmission on a non digital radio but it is definatly pretty intolerable...... I'm gonna moniter a site again tonight and try and catch a ID to try and decipher who is communicating... hmmmm with all that said I'm still looking for the book or website - "MARCS for dummies" :wink:

*NOTE* Being that this is jamboree in the hills weekend and I am not hearing nearly the amount of OSP traffic I would expect to hear (considering they've got about 30 units patroling over there....) that is why I'm finally trying to get this thing

 

[Mylan]

here is a follow up:

I have discovered that Post 7 does use their MARCS radios and they do have encryption option.... now my only question is about the different sites.... what determines what traffic can be heard on what site....???

 

[n8dhw]

Post 7

You will hear talkgroups from whomever's radio is affliated with the sites you are monitoring. And no you will not hear all of District 7's traffic. You only hear talkgroups on a site if there's a radio affiliated with that site. And OSP, ODNR, etc have the capability of toggling encryption on and off on there radio's. MARCS more or less is a mini cellphone style network. The radios look for the site that gives them the strongest signal and then affiliates with that site. So there radio can go from site to site and there talkgroup follows them.

I hope the above helps you understand it more.

Dave

 

[Mylan]

Thank you for replying; that helps a bit but I dont think I really like this system in this area. There are just too many trunking sites to scan them all at once..., esp. since there is only a few units that use it around here..... I guess if I had one radio dedicated to it it'd be alright.....

 

[antennaman1969]

re: Post 7
I live on a hilltop in Steubenville. I run a 796D, just logging on Scancat to see what I'm missing. Depending on sites are "open", or having voice routed to them, I can use as many as 7-8 banks on my scanner. Some nights lately, I only have the 2 statewide licensed towers on (WPQX322; Stratton & Mingo). Down your way, I can pick up 1-3 bars from the Kirkwood Hts. tower. It is clogged with I-calls and digital buzz from weak signal Post 7 traffic. I have turned that bank off for now, and the site near Piney Fork gives me solid audio. Depending on where you are in the Whg. area, see which couple of towers receive best, like New Alexandria, Kirkwood, or Powhatan-all along the river valley. Make sure the control channels are right, throw in some TG's from the RRDB, and run in ID search mode when you have time listen close. That tells you how much other OSP traffic or whatever else might cross your sites. I get OIU/liquor control, ODNR, Sheriff traffic on MARCS from the Jamboree; put the main TG's from each District 7 post, Columbus GHQ or aviation(air radar)-any you're curious about. I want to know if BECI is on the air or not. I can't receive any of the St.C site at all from home. Here's a weird one- during the day, I get steady traffic from Post 47 (Lorain)!
Just some thoughts and ramblings-might be some help. Good scanning to ya.
William

 

[WTFD10]

You will hear talkgroups from whomever's radio is affliated with the sites you are monitoring. And no you will not hear all of District 7's traffic. You only hear talkgroups on a site if there's a radio affiliated with that site. And OSP, ODNR, etc have the capability of toggling encryption on and off on there radio's. MARCS more or less is a mini cellphone style network. The radios look for the site that gives them the strongest signal and then affiliates with that site. So there radio can go from site to site and there talkgroup follows them.

I hope the above helps you understand it more.

Dave

I'm listening to Union County Fire today from the Toledo site (which by the way shows 99% signal here in Monroe, Michigan on my Pro 96 which is even better than the Michigan MPSCS simulcast county system up here LOL) Does this mean there is a radio from down there affliated this far north? Pretty cool...

 

[xusmarine1979]

That's one thing I didn't quite understand. On post 76 (Stark) I'd hear post 3 (Ashland). That would be constant. Same with Medina Co and Summit. I know Stark and Summit are joined posts but there's something I'm not getting here.

 

[n8dhw]

Yes it's quite possible that someone from Union County Fire was up in the Toledo area yesterday when you were hearing the traffic. I've heard them down here in Southwest Ohio before as well.

 

[antennaman1969]

RE: Post 7 for dummies

Hello, all...
I took Electronics in HS; I follow the concept of the TG's moving with the radio or whatever;(could use a link to do some heavy reading from), but I JUST don't buy the fact that I can monitor an out-of-area post or district because a 76 unit is in Jefferson County that day. I'm getting exact locations in their home post area. How does that explain OIU/liquor control? TG17600/Akron Calling encrypts half the time, so you can hear the mobiles give the name of the establishment at times, either going or leaving. Nowhere near my county, or towers. What I have done is put District 7 TGs in the closest towers, on the edges, East Liverpool has my District 4 TGs, East Springfield, Dists.2,3,4,7; Germano, Dist.6 & statewide TGs. I can get a lot of other stuff off the statewide licensed towers (WPQX322) that doesn't make sense. Is that an RF issue-are the mobiles-or the posts bombing some of these sites to ensure good comms? I'm assuming there's a way in the technology for the RF to vary up and down; aren't some of these sites rated for up to 20KW or more? If one got kicked wide open, could it open up others on its group or license, relaying traffic over a lightly-used network or TGs? The info I need may be in RR somewhere, any assistance/clarification is appreciated.
Scan on,
William

 

[xusmarine1979]

I'd have to agree with William on that. I'm gonna check out their site.

 

[16b]

...but I JUST don't buy the fact that I can monitor an out-of-area post or district because a 76 unit is in Jefferson County that day.

I don't know if this is going to help, but here goes...

Say, for example, that I am a highway patrolman. I am from post 49 (West Jefferson). I have to go to post 76 (Canton) for some reason. My radio is set to post 49 talkgroup for the entire drive. When I am in Canton (and everywhere in between), my radio is affiliated to the local MARCS site. This means that all radio traffic that comes over post 49 talkgroup is heard by me. When a post 49 mobile unit transmits, their transmission is routed through a network all the way from whatever site they are on to the site that I am affiliated with, and it is heard just as it would be in the Columbus area.

Now say that I am finished up at post 76. I transmit on my radio to tell the dispatcher that I am on my way back to post 49. My voice is routed from the local site all the way down to whatever sites the post 49 talkgroup is being broadcast on at the moment (probably the London and Columbus sites, at least).

The MARCS users do not have to put any thought into this "roaming" process; it is just like a cellular phone system.

If this helps a little, great. If not, well, disk space is cheap .

 

[mdulrich]

A Lima trooper got promoted to the Sandusky post, but was driving back and forth until he got moved. I would hear Post 22 traffic here in Lima before and after his shifts when his radio affiliated with the Allen County site. One morning on the way back home a car ran a red light in downtown Lima and crashed into his cruiser. He contacted Post 22 on his MARCS radio to contact Post 2 to report the accident and request an ambulance. (At the time, Post 2 wasn't on MARCS)

Mike

 

[antennaman1969]

RE: Post 7 For Dummies

Thanks Mike and 16b- that helps me to understand how the system is designed to work. My only other question is: are the sites on the statewide license able to carry any traffic, no matter where it comes from? And if I am following you both correctly, for me to hear OIU/Liquor Control from that far away, that means there is one of their vehicles based locally?
Thanks all, just soaking up info I didn't know before.
William

 

[mdulrich]

Any site can carry traffic from anywhere in the state, it all depends on radios that are affiliated and what channels are selected on those radios.

Mike

 

[mtindor]

How does that explain OIU/liquor control? TG17600/Akron Calling encrypts half the time, so you can hear the mobiles give the name of the establishment at times, either going or leaving. Nowhere near my county, or towers.

William

Actually, OIU/liquor control is often down here in Jefferson Co checking out our fine liquor-dispersing establishments. I have often heard them talk about the local places. The guys from Akron cover our area.

Mike