MARCS-IP ("New MARCS") Site and Talkgroup Discussion

[wa8pyr]

Your kidding right? If a license gets filed they are going to use the frequencies at that site. I am really thinking the guy at MARCS has his crap together a bit better than most as far as filing a license and getting the right stuff on it. And there are those of us on here that actually would KNOW what frequencies are going on a tower.... Ask Tom why... tell him I said it and he will explain it to you

We've had many cases in the past where not all of the licensed frequencies were used or some licensed frequencies were used for something else; there have been other cases where all frequencies were licensed at multiple sites, but were only used at one of them. Hence the requirement for actual, physical verification.

 

[FRANKtheFROWNER]

Hello I have been listening to the Ohio State Highway Patrol Posts 21 and 25 for a few years and finally decided to get a scanner. I'm having problems finding the correct talkgroup so that I can hear these transmissions. I have a BCD436HP, using Sentinel, I try to add the OSP channels and I keep getting "No Channels to Scan" Can anyone help? Please and thank you.

 

[GregOH]

Hello I have been listening to the Ohio State Highway Patrol Posts 21 and 25 for a few years and finally decided to get a scanner. I'm having problems finding the correct talkgroup so that I can hear these transmissions. I have a BCD436HP, using Sentinel, I try to add the OSP channels and I keep getting "No Channels to Scan" Can anyone help? Please and thank you.

You may have to append Franklin County sites to the favorites list if you haven't already and make sure list to monitor and download in set to On.

 

[WeldGuy]

When a new MARCS site is added to improve coverage, do LEO radios need to be individually updated to use the new site, or do the radios have the ability to be given a command to update themselves?

 

[kf8yk]

When a new MARCS site is added to improve coverage, do LEO radios need to be individually updated to use the new site, or do the radios have the ability to be given a command to update themselves?

The radios will find the new site automatically, no reprogramming required. Radios will learn the new control channel from: neighbor announcements on adjacent sites, searching a pre-programmed list of control channels, or completing a full spectrum scan. Radios also check the last used control channel first upon power up to speed up affiliation.

 

[wa8pyr]

The radios will find the new site automatically, no reprogramming required. Radios will learn the new control channel from: neighbor announcements on adjacent sites, searching a pre-programmed list of control channels, or completing a full spectrum scan. Radios also check the last used control channel first upon power up to speed up affiliation.

MARCS also re-uses control channels across the state, so there's a 99.9% likelihood that the control channels at the new site are already in the preprogrammed control channel list in user radios. This is actually the "first line of inquiry" when a radio is turned on; it searches the preprogrammed list for an active control channel, then if that CC isn't of very high quality uses the adjacent site data to find a better site. A full spectrum scan is the last resort as it can take quite awhile to go from the bottom of the 700 MHz band to the top of the 800 MHz band in 12.5 kHz steps.

 

[ohiogator]

Can I slide in here with a newbie question? I have a 436 that I mostly listen to Marcs-IP with. I live in rural Darke county and have a couple marcs towers nearby but have some tree and hill issues between my home and the towers. I have an antenna tower.....If I go with a 700-800 tuned yagi, will I be complete shut out on the lower bands?

 

[kf8yk]

MARCS also re-uses control channels across the state, so there's a 99.9% likelihood that the control channels at the new site are already in the preprogrammed control channel list in user radios. This is actually the "first line of inquiry" when a radio is turned on; it searches the preprogrammed list for an active control channel

The control channel list is actually third in line, the control channel search hierarchy at power up is:

1. Last used control channel
2. All control channels in the last used neighbor list
3. Pre-programmed control channel list - If a control channel is not found steps 1-3 are repeated up to four times
4. Full spectrum scan - At five minute intervals the full spectrum scan is paused and steps 1-3 are repeated. If nothing is found the full spectrum scan picks up where it left off.

 

[kf8yk]

Can I slide in here with a newbie question? I have a 436 that I mostly listen to Marcs-IP with. I live in rural Darke county and have a couple marcs towers nearby but have some tree and hill issues between my home and the towers. I have an antenna tower.....If I go with a 700-800 tuned yagi, will I be complete shut out on the lower bands?

Are you still using the rubber antenna that was supplied with your 436 scanner? It's not clear from your post if you are currently using an outdoor antenna on your tower or you just have access to the tower. If you are not currently using an outside antenna I would try a multi-band outdoor scanner antenna first before resorting to a band specific yagi.

 

[ohiogator]

Are you still using the rubber antenna that was supplied with your 436 scanner? It's not clear from your post if you are currently using an outdoor antenna on your tower or you just have access to the tower. If you are not currently using an outside antenna I would try a multi-band outdoor scanner antenna first before resorting to a band specific yagi.

I am currently using the rubber antenna that was included. I think I have settle on a larsen for the truck but I haven't picked a base antenna yet. I have a 30ft tower. It currently have 2 yagis on it for a cell phone booster and a LTE modem. Wasn't sure if any antenna I put up there would be prone to interference from the cell booster. I was going to try the Larsen 150/450/758 at home to see if it was sufficient enough to hit my marcs towers. I have one about 3 miles away (with large hill between), and one about 13 miles away.

 

[GregOH]

Question about how sites work...

I'm monitoring my home county (Tuscarawas) on a SDS100 and I get transmissions from neighboring counties and when I check which site I'm hearing them on it's Tuscarawas.

The neighboring counties that I'm hearing have their own sites and I'm wondering how I get them on the Tuscarawas site (which is simulcast and one of the neighboring counties is as well)?

 

[N8WCP]

Question about how sites work...

I'm monitoring my home county (Tuscarawas) on a SDS100 and I get transmissions from neighboring counties and when I check which site I'm hearing them on it's Tuscarawas.

The neighboring counties that I'm hearing have their own sites and I'm wondering how I get them on the Tuscarawas site (which is simulcast and one of the neighboring counties is as well)?

MARCS "Strategic Roaming Policy" allows users to access sites in their home county as well as counties they border. It sounds like a radio roamed to the Tusc site and that's why you're hearing the traffic. Also, state and federal have access to all sites.

 

[GregOH]

MARCS "Strategic Roaming Policy" allows users to access sites in their home county as well as counties they border. It sounds like a radio roamed to the Tusc site and that's why you're hearing the traffic. Also, state and federal have access to all sites.

And if they're close in proximity and listen to them every day, does that mean the sites link to one another?

 

[N8WCP]

And if they're close in proximity and listen to them every day, does that mean the sites link to one another?

Yes. As an example, if a Stark SO radio on TG 45160 affiliates with the Tusc site, any transmission on 45160 from the Stark site will be heard on the Tusc site. If another Stark SO radio is affiliated on the Summit site, then traffic would be heard on all three sites regardless of which site it originates from. Once the radio on the Tusc site returns to the Stark site, no further traffic would be heard on the Tusc site. All sites in Zone 2 are linked to a common zone controller which acts as a traffic switch routing calls between sites.

 

[GregOH]

Yes. As an example, if a Stark SO radio on TG 45160 affiliates with the Tusc site, any transmission on 45160 from the Stark site will be heard on the Tusc site. If another Stark SO radio is affiliated on the Summit site, then traffic would be heard on all three sites regardless of which site it originates from. Once the radio on the Tusc site returns to the Stark site, no further traffic would be heard on the Tusc site. All sites in Zone 2 are linked to a common zone controller which acts as a traffic switch routing calls between sites.

Coshocton is one I like to monitor and I've listened to many incidents happening there as well as routine stuff. I have the sites of that county programmed however, they are always heard on the Tusc site.

I have no complaints with it because if I wasn't getting them on the Tusc site, I'd never hear their SO and EMS comms.

Just trying to understand how it works. Yesterday I decided to avoid every site but Tusc and I did not hear Coshocton once after doing so, and I did this because I wondered if I have to have Coshocton sites enabled to get their comms on the Tusc site because scanning less sites should be more efficient.

 

[N8WCP]

Unless a Coshocton radio affiliates on the Tusc site on the TG you want to monitor, you'll need to scan their home site.

 

[GregOH]

Unless a Coshocton radio affiliates on the Tusc site on the TG you want to monitor, you'll need to scan their home site.

I monitor both their ems and So tg's. What's weird is some days it seems like they're all I hear and other days I hear very little of them.

 

[amcferrin90]

Wow I would just like to say it's nice to actually get past page 118! A mystical portal has opened in the time-space continuum. I'm going in....

 

[ohiodesperado]

I just heard through the grapevine that the MARCS system is the largest system of it's kind in the US. I assume this is based on the number of sites on a single controller. Now this is grapevine... but the source would certainly be in the know.

 

[wa8pyr]

I just heard through the grapevine that the MARCS system is the largest system of it's kind in the US. I assume this is based on the number of sites on a single controller. Now this is grapevine... but the source would certainly be in the know.

It's true. See the Minutes of the Steering Committee meeting:

https://das.ohio.gov/Portals/0/DASDivisions/InformationTechnology/IS/MARCS/Steering%20Committee/Draft%20Minutes%2012222020.pdf?ver=cXkeA4WYgffXUOJTY3N9HQ%3d%3d

There aren't any details but as there is at least one other statewide system out there with at least as many sites (Michigan), my guess would be that it's based on number of subscribers (both agencies and individual radios).