P25 simulcast help
Posted: Wed Feb 04, 2009 5:48 pm
Hi all.
After searching the forum, many questions have been answered, and I have gained a whole 'lotta knowledge. But I still need some advice/help. I have experience with Moto, but just analog stuff. So here I go.
My problem: Local PS is on a regional 700/800 Moto trunked P25 system (1a7). My particular county's site is actually a five tower Motorola P25 simulcast system. The simulcast is near impossible to rx using the GRE (other "regular" sites are perfect).
What I'm thinking: After pouring over white papers on P25 theory, etc, and looking over the data structure of a P25 transmission, the best I could come up with is this as a poor-mans solution.
Any P25 800 XTS, setting up as conventional rx, and using the TG #s to "filter" what comes through. I figure 11 voice channels, not too many TGs on system to "filter" through. Kind of similar to scanning for a particular CTCSS tone over many conventional channels, just using the TG info instead. Should be better than just randomly scanning the vc's.
My questions:
1. Is this possible? Is there a way to unmute audio based on TG info in conventional mode?
2. After bringing scan hang time to 0, will the radio scan and check for decode at a fast enough rate to pull this off?
3. Im thinking channel 1's scan list would have the systems voice channels in it's list, but just looking for specific TG info, repeat for ch 2, ch 3 , etc. Am I on the right track?
4. Will I gain anything as far as the simulcast is concerned? Will I be able to adjust for the systems' simulcast?
5. IF this is possible, any specific fw, etc I should look for? I assume an older 3600 radio would still work, as I wouldn't be trying to follow the 9600 trunk. (yes, I know the baud rate deal, just keeping it simple)
6. And last, any pitfalls to watch for would be appreciated. And if it is feasable, any particular flashes I should look for that would be conducive accomplishing this.
Just trying to get ANYTHING to hear this simulcast before moving on to "other" options. Not mission critical, just continuing my hobby.
Rich
After searching the forum, many questions have been answered, and I have gained a whole 'lotta knowledge. But I still need some advice/help. I have experience with Moto, but just analog stuff. So here I go.
My problem: Local PS is on a regional 700/800 Moto trunked P25 system (1a7). My particular county's site is actually a five tower Motorola P25 simulcast system. The simulcast is near impossible to rx using the GRE (other "regular" sites are perfect).
What I'm thinking: After pouring over white papers on P25 theory, etc, and looking over the data structure of a P25 transmission, the best I could come up with is this as a poor-mans solution.
Any P25 800 XTS, setting up as conventional rx, and using the TG #s to "filter" what comes through. I figure 11 voice channels, not too many TGs on system to "filter" through. Kind of similar to scanning for a particular CTCSS tone over many conventional channels, just using the TG info instead. Should be better than just randomly scanning the vc's.
My questions:
1. Is this possible? Is there a way to unmute audio based on TG info in conventional mode?
2. After bringing scan hang time to 0, will the radio scan and check for decode at a fast enough rate to pull this off?
3. Im thinking channel 1's scan list would have the systems voice channels in it's list, but just looking for specific TG info, repeat for ch 2, ch 3 , etc. Am I on the right track?
4. Will I gain anything as far as the simulcast is concerned? Will I be able to adjust for the systems' simulcast?
5. IF this is possible, any specific fw, etc I should look for? I assume an older 3600 radio would still work, as I wouldn't be trying to follow the 9600 trunk. (yes, I know the baud rate deal, just keeping it simple)
6. And last, any pitfalls to watch for would be appreciated. And if it is feasable, any particular flashes I should look for that would be conducive accomplishing this.
Just trying to get ANYTHING to hear this simulcast before moving on to "other" options. Not mission critical, just continuing my hobby.
Rich