Astra Communications

Business Two-Way Radios and Accessories

RPX Repeater


The legalese: On January 1, 2013, all public safety and business industrial land mobile radio systems operating in the 150-512 MHz radio bands must cease operating using 25 kHz efficiency technology, and begin operating using at least 12.5 kHz efficiency technology. This deadline is the result of an FCC effort that began almost two decades ago to ensure more efficient use of the spectrum and greater spectrum access for public safety and non-public safety users. Migration to 12.5 kHz efficiency technology (once referred to as Refarming, but now referred to as Narrowbanding) will allow the creation of additional channel capacity within the same radio spectrum, and support more users.  As of January 1, 2011, the Commission no longer accepts applications for new wideband 25 kHz operations, or modification of existing wideband 25 kHz stations that expand the authorized interference contour.

After January 1, 2013, licensees not operating at 12.5 kHz efficiency will be in violation of the Commission's rules and could be subject to FCC enforcement action, which may include admonishment, monetary fines, or loss of license. source:

What this means to Motorola Business Two-Way Radio users: Relax! Motorola Business Two-Way Radios have been capable of 12.5 kHz channel spacing since at least 1999 when the second generation Spirit M Series was introduced. If you are currently using XTN, CLS or RDX Series radios, chances are you have been licensed for and are already using 12.5 kHz channels. In fact, all current Motorola radios default to the 12.5 kHz setting.

If you are on an older license (say older than 10 years) that is for 25 kHz spacing, you will need to obtain a new license and program your radios to 12.5 kHz. Please call us if you need information on how to do that. If your radios cannot be programmed to 12.5 kHz they will need to be replaced with newer models.

In order to comply with FCC rules, Motorola will begin shipping radios that can only be used in 12.5 kHz mode. The RDX CPS 3.0 programming software complies with this mandate and will not allow 25 kHz channels to be programmed. It is fully compatible with earlier versions of the RDX radios.

CLS and XTN programming is performed via the front panel of the radio only so there is no software to download or update.

DTR Series digital radios operate on license-free 900 MHz and are excluded from all narrowbanding requirements.

Below is a collection of general questions on Narrowbanding.
Additional information can be found in Tech Topic #16. source:
Office of Engineering and Technology (OET) Q&A on Refarming Part 90 frequencies (pdf).

What is Narrowbanding?

Narrowbanding is an effort to ensure more efficient use of the VHF and UHF spectrum by requiring all VHF and UHF Public Safety and Industrial/Business land mobile radio (LMR) systems to migrate to at least 12.5 kHz efficiency technology by January 1, 2013.

More specifically, all existing Part 90 radio systems operating in the 150-174 MHz and 421-512 MHz bands have until January 1, 2013 to convert those systems either to a maximum bandwidth of 12.5 kHz or to a technology that provides at least one voice path per 12.5 kHz of bandwidth or equivalent efficiency.

What does Equivalent Efficiency mean?

Any of the following meet the 12.5 kHz equivalent efficiency requirement:

  • One voice path in a 12.5 kHz channel
  • Two voice paths in a 25 kHz channel
  • Data operations on channels greater than 12.5 KHz must employ data rates greater than 4.8 kbps per 6.25 kHz channel, such as 19.2 kbps per 25 kHz channel

What is the purpose of Narrowbanding?

Currently, the majority of UHF and VHF LMR licensees operate using 25 kHz efficiency technology. However, the UHF and VHF frequency bands are congested with limited spectrum available for system expansion or implementation of new systems. The migration to 12.5 kHz efficiency technology will require licensees to operate more efficiently, either on narrower channel bandwidths or increased voice paths on existing channels. This will allow creation of additional channels within the same spectrum, thereby supporting more users.

What frequency bands are subject to the Narrowbanding mandate?

The 150-174 MHz and 421-512 MHz bands are subject to the Narrowbanding mandate.

Are paging-only channels exempt from Narrowbanding?

Yes, however, there are only 14 paging-only channels.
152.0075 and 157.4500 MHz in the Public Safety Pool