Question about scanning in Toronto

[shteb13]

I have just gotten into the hobby of emergency service scanning and I was just wondering if others have had the same issue I have. When I am listening to TPS its seems like after a transmission is made the channel holds and then I will hear other channels on it. For example I will be hearing a call in 32 division, the transmission will end and then I will hear the dispacth calling a unit in 33 division (or something else). Is there a sensitivity setting that is too low or what could it be?

Please keep in mind that I am new to this...

Thnx for your help

I have a Uniden BC346T if it helps....

 

[EJB]

I have just gotten into the hobby of emergency service scanning and I was just wondering if others have had the same issue I have. When I am listening to TPS its seems like after a transmission is made the channel holds and then I will hear other channels on it. For example I will be hearing a call in 32 division, the transmission will end and then I will hear the dispacth calling a unit in 33 division (or something else). Is there a sensitivity setting that is too low or what could it be?

Please keep in mind that I am new to this...

Thnx for your help

I have a Uniden BC346T if it helps....

Most of Toronto's Police talkgroups for the divisions are patched together i.e; 32-33, the two Etobicoke, 11-12, 13-HWY, 51-53, 54-55.

 

[shteb13]

That is good info, and it makes sense but how about when my alpha tag says Div 32 and I am hearing EMS of Fire, and even Parking enforcement... are there settings that could have an effect?

 

[jonesyxvii]

That is good info, and it makes sense but how about when my alpha tag says Div 32 and I am hearing EMS of Fire, and even Parking enforcement... are there settings that could have an effect?

I've noticed the same thing when monitoring the Yonge/401 site. Seems to stick on one talkgroup but audio is definitely from another (incl. fire and EMS). I've never had that problem when monitoring the site at First Canadian Place. BCD396XT.

 

[EJB]

I dont think either of you two have your scanner properly set up.

Toronto Public Safety systems do have various TPS (Toronto Police Service) divisions patched as stated on my previous posts and there is no reason why you should be able to hear any EMS or FDP on any of the TPS talkgroups.
EMS and FDP talkgroups are generally not patched with TPS units. They should appear as different talkgroups.

You may wanna check if you have set up your scanner to correctly monitor a trunking system.

 

[exkalibur]

With respect to patched talkgroups, the following are (99.9999% of the time) patched together:

11-D11/12-D12
13-D13/61-HWY
22-D22/23-D23
32-D32/33-D33
51-D51/53-D53
54-D54/55-D55

So it would be perfectly normal to hear 54 and 55 Division calls on the same channel, for example.

To avoid the problem of hearing other TGs once the one you want has ended:

1) Don't use control channel only. Program in all the voice channels as well.
2) Set "End Code" to Detect.
3) Set the squelch control reasonably high (Mine is around 4 or 5).
4) Set the "status bit" to Ignore.

This will give you the best shot of hearing only the TGs you are interested in. Scanners have a bad habit of having false decodes - that is, tuning to a channel that doesn't exist, or tuning to a talkgroup that doesn't exist (or worse, both at the same time). By NOT using control channel only mode, you can eliminate the tuning to the wrong channel issue. Nothing can really be done about the false talkgroup.

Using End Code Detect will mean that the scanner is going to listen for a quick burst of data at the end of each voice comm which tells the radio to return to the control channel. By keeping the squelch high, this also ensures that should the scanner fail to hear the end code, it will "time out" and switch back - if it is too low, you might get stuck on a channel with noise. However, if the scanner doesn't catch the End Code, and the frequency is used again right away, you will hear those comms which aren't the ones you are interested in.

And finally, having Status Bit to Ignore means that the "status" of the talkgroup is ignored - that is, if it is patched, in emergency, multi-select, etc... Having it on "detect" means if the TG is ever patched, goes into emergency, etc...you won't hear it. This however CAN be good for TGs which are often encrypted, and will ensure you only hear when it is "in the clear". Unfortunately this is a system-wide option and not per-talkgroup (which it probably should be).

 

[jonesyxvii]

I dont think either of you two have your scanner properly set up.

Toronto Public Safety systems do have various TPS (Toronto Police Service) divisions patched as stated on my previous posts and there is no reason why you should be able to hear any EMS or FDP on any of the TPS talkgroups.
EMS and FDP talkgroups are generally not patched with TPS units. They should appear as different talkgroups.

You may wanna check if you have set up your scanner to correctly monitor a trunking system.

If this was the first time anyone had come across this, I might think you were right. However, this has come up before: http://forums.radioreference.com/ontario/180640-toronto.html

With respect to patched talkgroups, the following are (99.9999% of the time) patched together:

11-D11/12-D12
13-D13/61-HWY
22-D22/23-D23
32-D32/33-D33
51-D51/53-D53
54-D54/55-D55

So it would be perfectly normal to hear 54 and 55 Division calls on the same channel, for example.

To avoid the problem of hearing other TGs once the one you want has ended:

1) Don't use control channel only. Program in all the voice channels as well.
2) Set "End Code" to Detect.
3) Set the squelch control reasonably high (Mine is around 4 or 5).
4) Set the "status bit" to Ignore.

This will give you the best shot of hearing only the TGs you are interested in. Scanners have a bad habit of having false decodes - that is, tuning to a channel that doesn't exist, or tuning to a talkgroup that doesn't exist (or worse, both at the same time). By NOT using control channel only mode, you can eliminate the tuning to the wrong channel issue. Nothing can really be done about the false talkgroup.

Using End Code Detect will mean that the scanner is going to listen for a quick burst of data at the end of each voice comm which tells the radio to return to the control channel. By keeping the squelch high, this also ensures that should the scanner fail to hear the end code, it will "time out" and switch back - if it is too low, you might get stuck on a channel with noise. However, if the scanner doesn't catch the End Code, and the frequency is used again right away, you will hear those comms which aren't the ones you are interested in.

And finally, having Status Bit to Ignore means that the "status" of the talkgroup is ignored - that is, if it is patched, in emergency, multi-select, etc... Having it on "detect" means if the TG is ever patched, goes into emergency, etc...you won't hear it. This however CAN be good for TGs which are often encrypted, and will ensure you only hear when it is "in the clear". Unfortunately this is a system-wide option and not per-talkgroup (which it probably should be).

If setting a scanner up this way mitigates the "stickiness" issue, perhaps the database should be updated to reflect this.

 

[slicerwizard]

how about when my alpha tag says Div 32 and I am hearing EMS of Fire, and even Parking enforcement... are there settings that could have an effect?

I assume you're referring to hearing some 32/33 traffic and then hearing some other talkgroup while the scanner continues to show "32 Div" on the display.

Normally, when a talkgroup transmission ends, the trunking system sends a disconnect message over the voice channel; if you have End Code detection enabled, your scanner looks for this message and returns to the control channel when it sees it. From time to time, some systems fail to send the disconnect message. When this happens (or if your scanner just fails to decode the disconnect message), the scanner continues to monitor the voice channel. When the repeater stops transmitting, the scanner detects the loss of RF signal on the voice channel and that triggers a return to the control channel.

If a system is fairly busy, when a voice call ends, another talkgroup may be assigned to the channel before the repeater drops. If no disconnect message is sent, or if your scanner fails to decode it, you'll hear the second talkgroup while your scanner continues to display the alias for the first talkgroup.

One of the north zone voice channels has a history of staying keyed up for long periods, even when no talkgroup is using the channel; if your scanner fails to decode a disconnect message on that channel, it will continue to monitor that channel and you'll hear the next user (EMS, Fire, etc.) assigned to that channel and your scanner will display the alias of the first talkgroup. At some point, a disconnect message will move the scanner off of the voice channel.

 

[EJB]

If this was the first time anyone had come across this, I might think you were right. However, this has come up before: http://forums.radioreference.com/ontario/180640-toronto.html



If setting a scanner up this way mitigates the "stickiness" issue, perhaps the database should be updated to reflect this.

Agreed, I dont really monitor TPS anymore. When I did I never had many issues,
If the talkgroups appear on your scanner then at least you know it is set up to follow a trunking system.

Slicerwizard is a lot more informed though.

 

[shteb13]

With respect to patched talkgroups, the following are (99.9999% of the time) patched together:

11-D11/12-D12
13-D13/61-HWY
22-D22/23-D23
32-D32/33-D33
51-D51/53-D53
54-D54/55-D55

So it would be perfectly normal to hear 54 and 55 Division calls on the same channel, for example.

To avoid the problem of hearing other TGs once the one you want has ended:

1) Don't use control channel only. Program in all the voice channels as well.
2) Set "End Code" to Detect.
3) Set the squelch control reasonably high (Mine is around 4 or 5).
4) Set the "status bit" to Ignore.

This will give you the best shot of hearing only the TGs you are interested in. Scanners have a bad habit of having false decodes - that is, tuning to a channel that doesn't exist, or tuning to a talkgroup that doesn't exist (or worse, both at the same time). By NOT using control channel only mode, you can eliminate the tuning to the wrong channel issue. Nothing can really be done about the false talkgroup.

Using End Code Detect will mean that the scanner is going to listen for a quick burst of data at the end of each voice comm which tells the radio to return to the control channel. By keeping the squelch high, this also ensures that should the scanner fail to hear the end code, it will "time out" and switch back - if it is too low, you might get stuck on a channel with noise. However, if the scanner doesn't catch the End Code, and the frequency is used again right away, you will hear those comms which aren't the ones you are interested in.

And finally, having Status Bit to Ignore means that the "status" of the talkgroup is ignored - that is, if it is patched, in emergency, multi-select, etc... Having it on "detect" means if the TG is ever patched, goes into emergency, etc...you won't hear it. This however CAN be good for TGs which are often encrypted, and will ensure you only hear when it is "in the clear". Unfortunately this is a system-wide option and not per-talkgroup (which it probably should be).

Thank you for the tips I will try it and let you know the results

 

[exkalibur]

Further to what Andy said... The reason a "real" radio doesn't screw up when the channels hang... in addition to using the End Code, they also use a Connect Tone. In the case of TPS, that is 83.72Hz. Think of it as a PL tone. If it doesn't catch the End Code, and all there is is static, it'll switch back if it doesn't hear the Connect Tone. Also, the voice channel carries low speed data which identifies the talkgroup number currently being sent on that channel. Motorola radios decode this low speed data (the rumbling sound heard if you use a good pair of headphones) to also determine if they're hearing the right TG. If not...back to the control channel they go.

So, Scanners only have 2 checks (presence of a signal, and hearing the End Code). System radios (IE, Motorola radios) have presence of a signal, End Code, Connect Tone and Low Speed data.

 

[slicerwizard]

Connect tone is an inbound (subscriber to system) feature; if the tone is missing or incorrect, the subscriber audio is not passed to the repeater output. Outbound traffic carries low speed data and disconnect words.

 

[VE3RADIO]

Connect tone is an inbound (subscriber to system) feature; if the tone is missing or incorrect, the subscriber audio is not passed to the repeater output. Outbound traffic carries low speed data and disconnect words.

Another failsafe for those who use moto gear on TRS for RX.... wonder if the radio would still affiliate if there ws no TX inhibit? I know it would definatly try..

 

[mikewazowski]

Connect tone just prevents your audio from passing.

It does nothing to prevent affiliations or keyups.

Definitely not a failsafe.

 

[VE3RADIO]

Connect tone just prevents your audio from passing.

It does nothing to prevent affiliations or keyups.

Definitely not a failsafe.

Figured as much.. not that I would ever recomend anyone using Bat gear to RX without TX Inhibit set.