Hi all,
I was doing some standard searching with my BC296 today when it locked on to some P25 conversations that were coming in clear as a bell. If you remember from earlier this year and last year, I'd been lamenting the terrible performance of the BC296 on the Austin/Travis County system. Anyway, when I looked up the frequency, it was one of the Intellirepeater sites that I was listening to.
I immediately programmed the IR site into an unused bank of the scanner and started to track it. The amount of traffic was vastly reduced--I was only hearing a few units on TG 2405 (TCSO Adam)--but the transmissions were coming in crystal clear. And this was with ONE BAR of signal strength! This is vastly different to my experience tracking the Simulcast 1 system, in which the signal strength bar varies wildly between 2 and 5 bars and I get very poor decodes or garbled audio about 60% of the time and lose the control channel every so often.
So, my question is, what's the difference between the Intellirepeater sites and the main sites that would be causing this? I thought I remember hearing somewhere that the IR sites were using C4FM modulation whereas the simulcast sites were using CQPSK. (Or I may have the backwards, I'm not sure.) Secondly, I'm guessing given the limited traffic on the IR sites that they don't carry all the same traffic that the simulcast sites do. What governs this? Is it when there's a unit that's closer to the IR sites than the simulcast sites? I don't fully understand how they tie in to the main system.
I was doing some standard searching with my BC296 today when it locked on to some P25 conversations that were coming in clear as a bell. If you remember from earlier this year and last year, I'd been lamenting the terrible performance of the BC296 on the Austin/Travis County system. Anyway, when I looked up the frequency, it was one of the Intellirepeater sites that I was listening to.
I immediately programmed the IR site into an unused bank of the scanner and started to track it. The amount of traffic was vastly reduced--I was only hearing a few units on TG 2405 (TCSO Adam)--but the transmissions were coming in crystal clear. And this was with ONE BAR of signal strength! This is vastly different to my experience tracking the Simulcast 1 system, in which the signal strength bar varies wildly between 2 and 5 bars and I get very poor decodes or garbled audio about 60% of the time and lose the control channel every so often.
So, my question is, what's the difference between the Intellirepeater sites and the main sites that would be causing this? I thought I remember hearing somewhere that the IR sites were using C4FM modulation whereas the simulcast sites were using CQPSK. (Or I may have the backwards, I'm not sure.) Secondly, I'm guessing given the limited traffic on the IR sites that they don't carry all the same traffic that the simulcast sites do. What governs this? Is it when there's a unit that's closer to the IR sites than the simulcast sites? I don't fully understand how they tie in to the main system.
