1. Narrowband/Wideband VHF frequencies, and Digital/Analog Radios
Current and future Impacts to TNC’s fire programs
Sam Lindblom, TNC Fire Initiative

2. The Issue Increased radio frequency usage (more users)
Limited bandwidth available on the VHF spectrum
Much more conflict between users
Getting “walked” on…
Potential increased regulation by the FCC

3. The Solution Convert to Narrow Band radio frequencies and equipment
More on equipment later....
First, let’s look at the technology and the issue in more detail

4. What is Narrow Band?
Narrow band frequencies use ½ the bandwidth of wide-band
Normal wideband spacing is 25 Khz
Narrowband spacing is 12.5 Khz
For example, the TNCFIRE frequency is Normally, the next frequency up would be In narrow band, the next frequency is
Narrow banding essentially doubles the number of available frequencies in the VHF “Business” spectrum ( Mhz)

5. Sounds Great, right? PROS of Narrowband CONS of Narrowband
Less traffic on currently “shared” frequencies
Reduces the need to use tone/code guards
CONS of Narrowband
Operating wideband in a narrowband environment can cause problems
Requires specific radio equipment
Could be costly (more on that in a minute)
It’s likely to be a long time before the general public will be forced to use narrowband and all wideband radios are obsolete

7. Why would I want to convert to Narrowband radios?
If you regularly burn with federal partners, you will likely have to convert sooner than most
If you experience significant radio traffic where you work, narrowband could help (but only if everyone converts)
If you intend to participate on large wildland fire incidents of any kind

8. The FCC and Narrowbanding
The Federal Communications Commission mandated that all federal agencies convert by This mandate was lifted until further notice…
FCC does not currently have a time schedule in place to change the general licenses that we have now.

9. Equipment
Some existing radios that we have can be programmed to narrowband (most likely so if they were purchased in the last few years)
Bendix King EPH and GPH radios are OK
At this point, you should avoid radios that will not work on narrowband frequencies
Most radios require programming each individual frequency/channel as narrow or wide
Narrowband radios alone don’t significantly increase costs

10. What about Digital? The problem with Analog and Narrowband frequencies
Analog radios have a harder time sending and receiving narrowband frequencies, reducing their effective radiated power.
Certain analog radios can lose up to ½ of their transmit distance.

11. What about Digital?
Digital radios overcome this problem with a better capacity to process narrowband frequencies
They don’t typically suffer from the same loss in effective radiated power as analog.
Some digital radios using narrowband can theoretically transmit further than their analog counterparts using wideband
Digital radios are expensive
GPH Bendix King (Analog) is ~$500
DPH Bendix King (Digital) is ~$1200

12. Recommendations
Continue to purchase analog radios unless you have a big budget
Do not purchase radios that cannot process narrowband frequencies
Know how to program your radios
Know if you are working in a narrowband environment
Ask all of your local cooperators
Establish a communications plan if you contribute to local emergency response.