BCD536HP VS SDS100 on ME St Comm P25 Net

[Isinglass311]

Hi all, happy Independence Day eve. I’m spending the weekend in Franklin Cty and I have both my SDS100 and 536HP programmed with the P25 and Conventional ME State Comm Net. With the 536HP and SDS I received the conventional system just fine. With the P25 the SDS works great. The 536HP is completely deaf on the P25 system. I used Sentinel to program both, just switching the target model between uploads. I do have location control active on both and the range set the same at 10. Miles. The 536 will scan the system the same as the SDS but when the SDS locks onto a transmission the 536 goes right by it. Once in a while it will stop on the same frequency but no audio is heard.

The 536 is mounted in my truck with an external antenna while the SDS is handheld with a SRH-77CA diamond antenna. When monitoring just the conventional MSCN both units perform identical. Any ideas what may be going on? The only thing that comes to my mind is simulcast issues.

 

[a417]

With the P25 the SDS works great. The 536HP is completely deaf on the P25 system. <snip>
The 536 is mounted in my truck with an external antenna while the SDS is handheld with a SRH-77CA diamond antenna.
When monitoring just the conventional MSCN both units perform identical. Any ideas what may be going on? The only thing that comes to my mind is simulcast issues.

simulcast.

the conventional frequencies will work just fine, but you're seeing how simulcast makes the 536HP ineffective at scanning those systems.

Sorry, I didn't see this post earlier, hope you had a good 4th up here.

 

[KB1VLA]

The MSCOMNET system has NO networked simulcast sites, so that is not the issue. I would double check your programming and make sure you are in range of the sites you are trying to monitor. If you are scanning multiple sites one scanner maybe be receiving traffic from one site while the other is still searching for a control channel. I try to monitor only the sites nearest to me so the scanner isn't trying to find a far-off CC and missing traffic at a nearby site.

 

[a417]

The MSCOMNET system has NO networked simulcast sites, so that is not the issue. I would double check your programming and make sure you are in range of the sites you are trying to monitor. If you are scanning multiple sites one scanner maybe be receiving traffic from one site while the other is still searching for a control channel. I try to monitor only the sites nearest to me so the scanner isn't trying to find a far-off CC and missing traffic at a nearby site.

(reads) yep, you are correct!
I errantly assumed it was also simulcast like Portland's system. @Isinglass311 forget what I said about simulcast and try those suggestions next time you come up.

 

[BlackSheepDue]

I used a 536hp on MSCOMMNET for quite some time and was never happy with it. It caught a decent amount of traffic but I always felt like I was missing traffic. I've never used an SDS but they are suppose to be better with trunking systems I think.

 

[Ubbe]

There's one issue here that could be the problem. If users on TG1 are only on Site1 and users on TG2 are only on Site2 then the scanner will pass over Site2 if you are set to monitor TG1. If a TG1 user moves closer to Site2 then that user could switch over to Site2 and will begin to transmit TG1 calls on Site2.

Having a roof antenna with a high quality receiver like HP536 will receive sites much further away and probably several of them than what a SDS100 with it's own stubby antenna will do when probably receiving only one local site. If a scanner monitors a call on one site and that call ends it will jump to the next system, not the next site, and at the next scan cycle when it returns to the system it will first check the site that where active the previous scan cycle and start monitoring calls. If no calls are active when it first arrives to the site it will check all sites until it finds a call, or else go to the next system.

That 536 scanner could be more or less locked to a distant site while the SDS100 are monitoring only a local site, that carry more of the local TG's that you probably wish to monitor.

/Ubbe

 

[BlackSheepDue]

From the original post "I do have location control active on both and the range set the same at 10"

MSCOMMNET is a fairly spread out system and there's only 1 tower in Franklin county so I doubt he's picking up more than one even with the 536 unless he also has a range other than zero in the settings for each tower. 99% of the un-encrypted traffic on the system occurs on the zone primary so also unlikely that the two scanners would stop on different TG's, although not impossible. I would chock it up to the SDS being a better scanner.

 

[Ubbe]

From the original post "I do have location control active on both and the range set the same at 10"

MSCOMMNET is a fairly spread out system and there's only 1 tower in Franklin county so I doubt he's picking up more than one even with the 536 unless he also has a range other than zero in the settings for each tower.

Each tower seems to be set to 25 miles and the scanners 10 mile setting are valid for all sites and will make it 35 miles in total for a site.

I looked at the map and there seems to be several sites that reach into Franklin. But I can't find any Franklin City in Franklin County. If I assume it is Farmington City then Fish Hill and Garland in Penobscot County have coverage and probably others from adjacent counties when that 10 mile extra range are added. It's a VHF system so RF coverage are probably good and only the GPS steering are restricting the reception from a lot of sites when you have a VHF antenna on top of a car roof. The SDS100 antenna are more or less useless on VHF inside a car and will only pick up the local site.

/Ubbe