Friday, January 11, 2013

Narrow Band Report - 2013

The narrow band deadline is now past, or is it?

Most, not all, licensees have now converted to narrow band.  Most, not all, conversions have gone fairly well.  There are exceptions, in particular with those that have radios capable of operating in the companded mode.  The term companding may be new to you.  For additional information, click here

Without getting technical, there are various operating systems used by different manufacturers.  The idea is to compress and expand transmitted audio to reduce the effect of increased noise and reduced volume associated with narrow banding of 2-way radio channel bandwidth.

In theory, companding is a good thing.  In reality, it NOT such a good thing unless all of your radios are the same brand, or better yet, the same model. As you will see in the previously referenced patent information, there are numerous patent holders with Radio Shack being the originator.  You don't think Motorola, Kenwood, or ICOM is going to pay Radio Shack patent royalties do you?

The result is that the companding systems apparently work only on tone squelch activated channels and only with radios of the individual manufacturer.  I haven't found any evidence to support this theory except to say if you have a mixed brand radio system, it will work better if you turn the companding option OFF!

As far as reduced audio is concerned, make sure that you choose analog portable radios with the highest audio output available.  500 millwatts (mW) is fine for wide band (25 kHz) channels or for narrow band (12.5 kHz) or very narrow band (6.25 kHz) DIGITAL channels.  500 millwatts is not recommended for narrow band ANALOG radio systems.  700 mW's is our recommended minimum with 1000 mW being the best choice if available.

Digital Audio Processing (DAP) also improves signal quality for analog narrow band radio systems.  Many of the older repeaters will convert to narrow band, but we recommend replacement with a new repeater such as the Hytera RD-982AN.  You can trade in your old repeater and get a brand new 50 watt analog repeater for less than a thousand dollars!  Better yet, you get a five year warranty, and this repeater can be upgraded to DMR digital when you are ready (DMR is the digital format offered by Hytera and Motorola).

Give us a call at 800.489.2611.  Tell us what you have to trade and we'll take it from there!  In the meantime, if you are having low audio problems after narrow banding mixed brand radios, we suggest that you turn the Companding option OFF!.  P.S.  That's a picture of the RD-982AN above.  It is built to last for a long, long time and it is fully compatible with the incredible Hytera Smart Dispatch system.

For additional information on narrow banding, on the topics of operation considerations, discussions on upgrading to digital, regulatory (FCC policies, enforcement, etc.) and technical issues, just type in the word narrow banding in the Search Box above the date at the beginning of this posting.