12.5 Ghz vs 6.25 Ghz

I’m looking at two proposals for business radios, repeater(s), licensing and programming from two vendors.

The Motorola solution is using a 12.5 kHz split channel setup while the Kenwood solution offers true 6.25 kHz channels.

The two quotes are nearly identical in price and functionality, so my questions:

[li]Does anyone know if the FCC will ask Motorola to drop down to true 6.25 kHz channels? [/li]
[li]And what other functions might be different? (e.g. radio to radio comms if the repeater goes down, etc.)[/li][/ul]

Thanks in advance if anyone has insight. Making a decision this week probably.

Great question! I’m sure a lot of people wonder the same things, and I can’t find where we’ve addressed these before.

As you’ve probably already been made aware, there are (primarily) two types of digital radio systems, and they are not compatible with each other. The DMR digital standard is used by Motorola, Vertex Standard, and Hytera. Digital radios from Kenwood and Icom use the NXDN standard. With NXDN, each channel can use as little as 6.25 kHz of bandwidth. With DMR each frequency will consume 12.5 kHz of bandwith, however the technology allow you to use two distinct channels for each frequency.

I have heard from customers that Kenwood and Icom dealers may sometimes mention that the FCC could, in the future, force everyone to use 6.25 kHz like they did with 12.5 kHz a few years ago (basically making all 25.0 kHz equipment worthless). I consider this a scare tactic. The FCC has been using the phrase “6.25 kHz equivalent” in regards to new technology. DMR technology fits into this category because two channels in a single 12.5 kHz frequency is effectively 6.25 kHz each. DMR is the leading digital technology and it is used by the largest radio manufacturer in the world. I can’t see the FCC changing the rules regarding this for a long long time.

Both systems offer a lot of the same functionality. The benefits depend on how big of a system you will have. For businesses that aren’t doing trunking and only need one or two repeaters I prefer DMR simply because a single repeater can provide two distinct channels.

I don’t know how far into the process you are, but please take a look at what we have to offer. We are a dealer for the Vertex Standard eVerge series, which offer much of the same functionality of Motorola TRBO for a considerably lower price. (Vertex Standard is owned by Motorola, BTW.) If you decide on an NXDN system, we can offer an Icom solution. Icom’s entry level digital radios are less than $300, so they are quite popular (sorry, Icom doesn’t allow us to advertise our real price publicly.) We also offer frequency licensing and provide free programming in most cases.

Ok thanks, that helps a lot. I’m leaning more towards the DMR solution at this point. Motorola says their CLS1410 are capable of 12.5 narrowbanding. Is this something we can do in programming with our existing CLS1410’s to connect to the new radios through the repeaters? Or are they limited to just 12.5 kHz channels only?

The CLS1410’s are analog only, they wouldn’t be compatible with any digital system (including DMR). They also aren’t able to be programmed for a repeater.

Both the Kenwood and Motorola digital radios also support analog, so if you needed it you could program a channel on your new radios to match a channel on the CLS1410’s. It would be radio-to-radio communications and would not go through a repeater.

As an example, let’s say you go with a DMR system and get a single repeater. You could program channels 1 and 2 on your new digital radios to use the repeater, and channel 3 could be programmed to talk analog to the CLS1410 channel 1. (Be aware, most frequencies built-in to the CLS1410 have a 2 watt limit, so you would need to setup that channel to use low power on the DMR radios. Your radio dealer can take care of this for you.)