Trunked System Question

[mistermightymoose]

Hello,

I'm trying to monitor the fire department in Sudbury, Ontario. I have a HomePatrol 1 and I'm using the database from Radio Reference (Greater Sudbury Trunking System, Sudbury, Ontario - Scanner Frequencies).

The only thing that I have scanning is the Fire Service, but I seem to missing some replies or initial keyups.

My question is around my programming of the scanner. I live nearest to Wahnapitae, so I've programmed it to only those control channels. Do I need to have the different talk groups identified. Presently I have them all listed, but I'm wondering if having them in the scanner is slowing down the scanning?

Any suggestions would be greatly appreciated. I have checked the signal strength and it seems to be 80% or more... I have tried tweaking the delay settings under audio options.. I feel like something could be changed to make things work better.

Thanks!

 

[tvengr]

You need all 9 frequencies in the site since they show as either a control channel or alternate. Standard scan delay is 2 seconds. Site hold time normally set to 0. It should be programmed as a P25 Standard system type and site type. I don't see any site or modulation info to determine if it is a simulcast system. Simulcast distortion can cause problems like that. Programming all of the talkgroups will not slow it down. If you export a hpe file of you favorites list and attach it, I will check it for problems.

 

[mistermightymoose]

Hi,

Thank you! I had to zip the file because the *hpe extension wasn't being accepted by this site. If you wouldn't mind having a look at the file and letting me know if I've done anything wrong I'd really appreciate it.

Thanks again!

 

[tvengr]

I don't see any problems with the programming. With the scan delay set at 1 second, you will miss a lot of replies. I suggest that you increase it to 2 seconds. Also, make sure that the squelch is set at the minimum level, just enough to quiet the noise on conventional frequencies without PL tones. Have the 150 band frequencies been narrowbanded in Canada?

 

[mistermightymoose]

I don't see any problems with the programming. With the scan delay set at 1 second, you will miss a lot of replies. I suggest that you increase it to 2 seconds. Also, make sure that the squelch is set at the minimum level, just enough to quiet the noise on conventional frequencies without PL tones. Have the 150 band frequencies been narrowbanded in Canada?

Thanks! I'll change the delay to 2 seconds and I'll check the squelch. I think that I had it at 2 bars on the HomePatrol... Should I be using the attenuator setting?

I'm not sure about the narrowbanding of frequencies, sorry. I'm still a real novice learner with this scanner stuff.

Thanks again!

 

[tvengr]

You might try changing the 150 conventional frequencies to NFM to see if that makes an improvement.

 

[mistermightymoose]

Thanks! I'm looking in Sentinel under my Favourite List and I don't see any option to change from FM to NFM... am I missing something?

 

[hiegtx]

Thanks! I'm looking in Sentinel under my Favourite List and I don't see any option to change from FM to NFM... am I missing something?

That can be changed by using the Favorites editor,


The Modulation column is where you would make the change.

 

[kayn1n32008]

Have the 150 band frequencies been narrowbanded in Canada?

137-174MHz And 400-470MHz have not been blanket ‘narrowbanded’ like in the US. However... in congested areas you will find a mix of wide and narrow band frequencies in the VHF and UHF spectrum. It all depends on the area and the ISED(Canada’s version of the FCC) spectrum manager.

 

[tvengr]

137-174MHz And 400-470MHz have not been blanket ‘narrowbanded’ like in the US. However... in congested areas you will find a mix of wide and narrow band frequencies in the VHF and UHF spectrum. It all depends on the area and the ISED(Canada’s version of the FCC) spectrum manager.

Thanks for the info! Good to hear from our friends in Canada.

 

[mistermightymoose]

Thanks! For the trunked system I don't seem to get the modulation option in Sentinel.

I changed the delay to 2 seconds and it still seems to be missing replies. I'm not sure if the delay is too long and the reply comes in on a different talkgroup channel and it's not switching to it quick enough?

 

[Ubbe]

When you say 80% signal strenght, is that the 5 bars at the top right in the display that then show 4 bars?
The thing with Uniden scanners are that if you loose one bar in the signal strenght then the signal are beginning to be too weak to be able to decode digital data properly. Having 2 bars are almost a non existing signal.

Replys almost always comes on the same TG. Set the TG delay to 5 sec to be sure that the scanner doesn't move away to the next system before the replyant starts to transmit. Most users in the systems I monitor think before they transmit, and that could take 5-10 seconds. I know others that instantly transmits and then goes "Hummm, hmmmm, let me think,"

But your issue with the HP-1 are probably a too weak signal and could need a better antenna or position it better, if that is possible. Using a longer TG delay time and also a longer hold time, like 3-4 sec, will usually help in weak signal enviroments.

/Ubbe

 

[mistermightymoose]

When you say 80% signal strenght, is that the 5 bars at the top right in the display that then show 4 bars?
The thing with Uniden scanners are that if you loose one bar in the signal strenght then the signal are beginning to be too weak to be able to decode digital data properly. Having 2 bars are almost a non existing signal.

Replys almost always comes on the same TG. Set the TG delay to 5 sec to be sure that the scanner doesn't move away to the next system before the replyant starts to transmit. Most users in the systems I monitor think before they transmit, and that could take 5-10 seconds. I know others that instantly transmits and then goes "Hummm, hmmmm, let me think,"

But your issue with the HP-1 are probably a too weak signal and could need a better antenna or position it better, if that is possible. Using a longer TG delay time and also a longer hold time, like 3-4 sec, will usually help in weak signal enviroments.

/Ubbe

Thanks for the reply.

I purchased the extreme part for the HomePatrol so I could analyze the system. It gives me a bar with signal strength and it sits around 80%+... and it says digital decoding is 100% (so I'm assuming that it's good with the signal strength).

When I watch the scanner there is often a change in the talk group as it gives the response. So, if a call goes out from Channel A, the reply comes back on Channel B. It appears to me that Channel A keys up... Channel B replies and is missed by the scanner... and then I hear Channel A responding. I hope that makes sense. I can try the 5 second delay and see what happens.

 

[Ubbe]

You can set priority to the TG's that are used for the replies. The scanner checks prio TGs while another TG is in idle, when a user has stopped transmitting on it. When the dispatcher stops transmitting on TG1 and the scanner goes to the control channel, it will wait there for the delay time, lets say you have that set to 5 seconds, and check TG2, that you have set to prio, for any activity and will jump to it as soon as it goes active.

It will give unpredictable results if you have several prio TG's and they are active at the same time for different calls. It could then jump to the wrong response.

If you have a too short TG delay, like 1-2 seconds, the scanner will continue to scan to the next system after the delay time and you'll miss the response as you have to wait for the scanner to go one full scan circle. Not a good solution in your situation when a call and a response uses different TG's.

I guess that what you see are some sort of multi TG call from the dispatcher and the units respond to one of the TG's. Dispatcher might transmit simultaniuosly on TG1-TG2-TG3-TG4 that represents different location areas South, North and so on, and when a unit respond it will only be heard by units in his own district, who then knows whats going on and can quickly assist. Units in other districts are too far away to be of any help and are spared the response commnication and of any "intercom" between units in that other district, that would not be the case if patched TG's where used that have a single TG number for all patched TG's.

/Ubbe