Tuesday, June 22, 2010

USFS Columbia Dispatch Using P-25 Digital

Over the last year or so there have been rumors of upgrades to the radio systems used by Mt. Hood National Forest and Gifford-Pinchot National Forest in northwestern Oregon and southwestern Washington. They have apparently combined some of the radio dispatching and are now identifying as "Columbia Dispatch" in the two National Forests, but so far no new frequencies have been discovered - until a couple of weeks ago.

The two national forest areas utilize VHF repeaters and UHF point-to-point links for radio communications. Recently the frequency of 417.9875 MHz, N68F has sometimes been heard carrying the dispatcher in P-25 digital. The frequency should be paired with 408.9875 MHz, but we haven't heard anything on that link yet. The P-25 NAC of N68F is interesting, as this NAC has previously been identified as being used on the federal interoperability systems.

Despite being a digital link, the VHF frequencies are all still analog. However, this may indicate that they have upgraded the core of the system to digital and can flip the switch at any time!

A while back I found this document on line that lists the frequencies for some of these UHF links:
https://www.fbo.gov/index?s=opportunity&mode=form&id=7d3481f79285eab7adb988ff06dfa778&tab=core&_cview=1

According to the frequencies listed on this document, the 417.9875 MHz link is to Mt Mitchell in the Gifford-Pinchot National Forest.

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