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Wideband has a slight advantage (3dB) over narrowband when it comes to sensitivity. Cutting the bandwidth in half requires 6dB more power to get the same signal-to-noise ratio, but 3dB comes from having the noise power on the narrower receive IF filter. On business radio systems, this may not matter; but on GMRS, the users tend to be dispersed further as operating area isn't constrained by the license and minimal frequency coordination takes place. This effect also causes mobile flutter to be more pronounced. On modern commercial radios designed for narrowband use, the strong-signal voice quality doesn't take much of a hit when moving to narrowband channels. We can't get any more pairs because FRS is already authorized for the 467 MHz interstitials. We'd need to go to 6.25 kHz ultra-narrowbanding (NXDN48 or dPMR) and use some odd channels (462.546875, 462.553125, 462.559375, ...), which won't happen anyways because digital voice isn't allowed. Adjacent ultra-narrowband channels would also interfere unless frequency accuracy is well-controlled, which raises equipment cost considerably (particularly for portables) and requires realignment during the equipment's service life. Additionally, wideband users would take interference from any of four ultra-narrowband channels, and narrowband users would take interference from any of two ultra-narrowband channels. The end result is even less voice capacity than before, unless everyone goes ultra-narrowband and maintains their equipment to high standards. The repeater operator always has the option to narrowband should they want to, but there's no benefit unless there's significant adjacent-channel interference, all of the radios are properly configured for narrowband (travelers are probably not), and the radios used on the system have proper 12.5 kHz IF filters (the GMRS-V1 does not). A narrowband mandate would also screw up equipment certifications and cause the FCC to get a big headache over something that is not really a problem at all.

There's a local, open repeater that uses multiple PLs. There's no defined purpose to all the PLs, but it mainly allows the repeater to have travel tone and a separate local tone. The rest of the tones are mostly for sticking a group of people on the repeater without the other repeater users having to hear them. 67.0 Hz output tone is available to address FRS users for emcomm. Having a bunch of tones available makes the repeater really susceptible to interference, and all the radios need to be set up with busy-channel lockout (which works a lot better when the repeater has a short hangtime of 0.5-1.0 seconds). Things start getting nutty when there's more than 3 tones configured on a repeater.

link to software https://hamfiles.co.uk/index.php?page=downloads&type=entry&id=radio-programming%2Fkenwood-programming%2Fkenwood-kpg-49d-rss_2 the TK-880 s are great radios welcome to the forum

Congrats on getting the best radio out there for GMRS! Chirp won't work. It would be great if it were added at some point, but KPG49D is readily available free, and works well. Look for version 4.xx for Windows. I have a Windows 10 machine and it works fine except for the help files, which you don't necessarily need anyway. I originally started with Version 6.xx, thinking the later version would be better. But nope, it was DOS only. Once you have the software, it will also work (with a different cable) on the TK-380 uhf HT. And btw, the TK-880 can be easily programmed with freqs down to 440 or maybe even lower. The software will warn you that it's out of range, but it will accept it. Most radios are deaf below 446 or so though, and the vco also loses lock. There are a couple of simple adjustments to make it work down there while not sacrificing operation up to 470. The TK-380 works on 440 without needing any adjustments. Welcome to the forum.

You get more fidelity at a given power level using a wider deviation. You need more power (a net change of 3dB in this case) to reproduce a transmitted signal with the same fidelity. So if you've got a receiver trying to receive your buddy down in the valley and you're in a theoretically perfect hilltop site, you'll have -130dBm of thermal noise coming in. If everything is wideband, your buddy needs to be received with some signal-to-noise ratio to achieve some level of fidelity. Let's arbitrarily set that threshold -122dBm to achieve a good-enough signal. If your buddy switches to a narrowband radio and you switch the repeater to a narrowband configuration, you'll have a narrower IF filter and thus less thermal noise within the IF passband: -133dBm. Passing the input signal at the same signal-to-noise ratio (which would be received at -125dBm) will not reproduce the input signal at the same degree of fidelity -- it'll sound worse. You're trying to do the same thing with less RF, it just doesn't work like that, or we'd have been 6.25 kHz compliant for a long time. The signal-to-noise ratio needs to improve by 6dB each time the bandwidth is halved to produce the same fidelity, and we gained 3dB from the narrower IF filter. To get the same fidelity, we'd need a received signal at -118dBm. The easy way out of the problem is to lowpass the audio so less noise is audible, and that's one of the reasons you'll hear a lot of people say narrowband sounds like junk. The audio loses fidelity in the process, but has less high-pitched hiss from FM noise. The problem is with reproducing the transmitted frequency range. More and more RF power is needed to allow the higher pitches to be demodulated with an audio SNR above a fixed threshold as IF bandwidth goes down. It's a property of FM.

You can't use analog RF linking on GMRS. There's nowhere to put the links anyways. Use point-to-point Wi-Fi for building networks. If the repeater's receive side is solid in all desired locations, try improving the repeater's sensitivity with more robust filtering and a LNA before trying to figure out where you're going to put a bunch of voting receivers. Simulcasting would be overkill. RTCMs don't take a 10 MHz clock directly, they require some PLL device to shift the frequency down to 9.6 MHz. There's plans to build such a device that are readily available, but there isn't an off-the-shelf solution. A 9.6 MHz OCXO would work for voting purposes as well. All of this is far more complicated than improving the repeater's receiver, since it turns a standard duplex repeater into a computer-controlled radio network.

Depending on the firmware, the KPG-49D should be what you need. There is a firmware that requires passport software. This can be determined by watching the screen as you turn on the radio. If you have firmware 1.5xxx chances are you have passport firmware. This is easily fixed by reflashing the newest firmware through Fpro which is included with the 49D software. As far as I am aware (And I may be wrong on this) the 880's are incompatible with CHiRP. I think I got my 49D from hamfiles for free. If you have an account there you should be able to download the file there. If you need the firmware feel free to message me and I'll send it over.