Multi band, simulcast system

[wyomingmedic]

I have a pro-197 that I am changing up a bit. To save room, I want to minimize the number of systems.

I have a system made that has VHF and 800mhz control channels. The system is also simulcast, partially. Some TGs are simulcast while others are not, yet still on the same system.

Is it a problem programming multi band stuff into a single system, or do I need to separate them to make it work correctly? I can't figure why it would not work, but who knows.

Thanks,
WM

 

[DickH]

... Some TGs are simulcast while others are not, yet still on the same system.

That doesn't make sense. Please explain more clearly. Systems are simulcast, not Talk Groups. Simulcast means more than one transmitter sending the exact same info. at the exact same time. In my city there are 4 simulcast sites.

 

[Thayne]

If you are talking about the Wyolink VHF system and some of the Wyoming cities that use 800 and yet have some "simulcast" common talkgroups, you should keep the separate systems because the talkgroups are not true simulcast as we usually think, because the audio is patched between the systems; your scanner would not work very well if at all because it would be dealing with switching between two systems, and maybe the firmware would not even let you enter VHF & 800 freqs into a trunked system. Maybe someone like Don Starr will chime in that really knows---

 

[wyomingmedic]

That doesn't make sense. Please explain more clearly. Systems are simulcast, not Talk Groups. Simulcast means more than one transmitter sending the exact same info. at the exact same time. In my city there are 4 simulcast sites.

Statewide system, but also tied into a county system. Certain TGs are activated on 4 or 5 towers at the same time. I guess, it isn't technically simulcast. Yet other TGs are only active on 1 tower at a time. It is a bit of an RF nightmare. Multiple agencies using both VHF and 800mhz, all on the same TGs, all the time. Yet others who are strictly VHF and others are strictly 800mhz.

From the subscriber radio side, it is rather simple. But from the scanner side, there are areas where 800 does not have coverage while VHF will, and visa versa. All depending on affiliated subscriber units and where they are. But if you get it programmed correctly, a scanner listener can have very seamless coverage.

WM

 

[wyomingmedic]

If you are talking about the Wyolink VHF system and some of the Wyoming cities that use 800 and yet have some "simulcast" common talkgroups, you should keep the separate systems because the talkgroups are not true simulcast as we usually think, because the audio is patched between the systems; your scanner would not work very well if at all because it would be dealing with switching between two systems, and maybe the firmware would not even let you enter VHF & 800 freqs into a trunked system. Maybe someone like Don Starr will chime in that really knows---

Kinda what I was thinking. On a whim, I am playing with it. ARC500 lets you put in whatever frequencies you want. SO I have both VHF and 800mhz active control channels in the same system.

It is a little odd. I am catching all traffic, but the displayed frequency is WAY off. I have both VHF and 800mhz subscriber units at my disposal, and have been toying with they system. I think I am going to keep them separate in the scanner. But some more testing will ensue.

WM

 

[Thayne]

Kinda what I was thinking. On a whim, I am playing with it. ARC500 lets you put in whatever frequencies you want. SO I have both VHF and 800mhz active control channels in the same system.

It is a little odd. I am catching all traffic, but the displayed frequency is WAY off. I have both VHF and 800mhz subscriber units at my disposal, and have been toying with they system. I think I am going to keep them separate in the scanner. But some more testing will ensue.

WM

Interesting; I am surprised that nobody else has added any thoughts. Might as well play around since you have everything you need to do it---One thing for sure is that scanners are way more sophisticated now.

 

[wyomingmedic]

Interesting; I am surprised that nobody else has added any thoughts. Might as well play around since you have everything you need to do it---One thing for sure is that scanners are way more sophisticated now.

I'm kinda shocked as well. With most of my questions here, it has been done by lots of people and I get an ton of answers. Maybe I'm the first one to do what I have lol. Doubt it, but maybe.

The scanning seems to work, but does act odd. I am catching all traffic that I expect, but I can't make heads or tails of it. For example, if a VHF signal is received, I can force the scanner to scan with the idea that it will catch the same traffic on 800mhz. But instead of catching it on 800 ( which I know it is there), it goes back to VHF (at least that is what the display shows) but shows it on one of the voice frequencies that does not exist in the system. Does that make sense?

It also happens the other way around, 800 to VHF.

And it seems more prone to tailending, where the channel will stay open while another TG gets assigned to it.

WM

 

[Thayne]

I used to argue with others sometimes about putting dummy freqs between CC's on the Pro-96-2096 scanners, (to force it to sample other CC's) but the new stuff gave us other options.

In general, I think putting freqs from both bands in one trunk system would confuse any radios' brain

I have a 2096 that is locked just on 1 talkgroup but have it scanning 5 CC's and sometimes it will let other talkgroups thru for one transmission because it gets left behind and stays on the same voice freq.

 

[hpycmpr]

You're comment on displaying channels that aren't in the system makes me think that the trunk tables aren't complete. Perhaps the tables are set for one band only and the radio is using the wrong channeling for the other band.
I have programed Wyolink sucessfully for statewide coverage, but not programmed the 800 MHz channels. I try to stay out of bigger cities - one's enough;>)
Try adding the other trunk band table and see if that works. If there's a problem in doing what you want I suspect the trunk tables may be the problem.
Let us know how that works.

Steve

If that doesn't work then create two TSYS. You can merge the TG's in one or more scan lists.

 

[wyomingmedic]

You're comment on displaying channels that aren't in the system makes me think that the trunk tables aren't complete. Perhaps the tables are set for one band only and the radio is using the wrong channeling for the other band.
I have programed Wyolink sucessfully for statewide coverage, but not programmed the 800 MHz channels. I try to stay out of bigger cities - one's enough;>)
Try adding the other trunk band table and see if that works. If there's a problem in doing what you want I suspect the trunk tables may be the problem.
Let us know how that works.

Steve

If that doesn't work then create two TSYS. You can merge the TG's in one or more scan lists.

Interesting thought. I have not done any messing with the TTs as the system did not require it. Just took off running. But clearly the radio is trying to move stuff where it isn't at.

Ya, I had it setup originally as 2systems which works great. But necessity is the mother of invention and I needed more room.

WM

 

[hpycmpr]

Since the trunk control channels and the trunk tables are two separate entities, I don't see how the any control channel would associate with the right trunk table. It would seem that it would end up on a first come, first served basis and that's what you're seeing.
Perhaps that would be a good question to ask in the Scanner Programmer Software forum for DonS to answer.

Steve