WHY NXDN?

First off, lets be clear that the choice is purely personal.

 

Why did we choose NXDN (FDMA) over DMR (TDMA)?

 

All NXDN radios will operate in simplex digital mode. They are not dependent upon a repeater to assign a time slot. In an emergency situation, you can grab the radios, go, and quickly establish digital emergency communications. No waiting for a repeater to show up. All NXDN radios can do digital Talk Around. Different brands of NXDN radios will talk to each other digitally, right now. All technologies agree that digital range exceeds analog.

 

True 6.25KHz. You are only using 6.25KHz when you transmit. True, not equivalent, 6.25KHZ bandwidth. This allows you to have 4 times the number of independent repeaters in an area versus 1 in a 25KHz mode and 2 times as many as a DMR system. A DMR uses 12KHz bandwidth, or the equivalent of 2 NXDN channels. This denies another ham from having an adjacent frequency, since one DMR repeater owner is tying up 2 repeater channels (frequencies).

 

Frequency division. All hams understand frequency division. It is what is currently used in the analog mode. No need to learn about time slots, syncing, etc. All that is done behind the scenes by the radio.

 

The initial cost is more for NXDN than DMR if your requirements are that you must operate on two frequencies. NXDN requires 2 repeaters, whereas DMR can do it with one. The tradeoff is system reliability. If one NXDN repeater fails, you don't lose both channels.

 

Better range? Narrower signal, 6.25KHz vs. 12.5KHz, equals a narrower, and lower noise floor.

 

We are hams that believe that the better we manage spectrum effecency, the more hams will be able to experiment with setting up and runing their own repeater. We do not believe in being frequency hogs. Its not about collecting frequencies, but rather growing the hobby. The less bandwidth we use, the more of our fellow hams can enjoy the hobby. Four 25KHz channels would equate to 16 NXDN channels. With only those four 25KHz channels, we could cover most of the country!

Cheers!