167.1125 Question

[iscanvnc2]

Today I picked up 167.1125 NAC 167 encrypted making it the FBI
Then I noticed in the RRDB under the United States Forest Service Region 5 Common Channels that 167.1125 is listed as Tac 5.
Are both the above true? I question the FBI & USFS sharing a frequency.

 

[ecps92]

Yes, not all frequencies are exclusive to an agency

For CA, 167.1125 has been noted with
CSQ/NO PL for USFS Region 5 Tac 5 - came around in 2010
$167 for LA Area and is the FBI
$373 for another unk area of CA
could be others not reported

Today I picked up 167.1125 NAC 167 encrypted making it the FBI
Then I noticed in the RRDB under the United States Forest Service Region 5 Common Channels that 167.1125 is listed as Tac 5.
Are both the above true? I question the FBI & USFS sharing a frequency.

 

[iscanvnc2]

Yes, not all frequencies are exclusive to an agency

For CA, 167.1125 has been noted with
CSQ/NO PL for USFS Region 5 Tac 5 - came around in 2010
$167 for LA Area and is the FBI
$373 for another unk area of CA
could be others not reported

Thanks for the verification.

 

[norcalscan]

I question the FBI & USFS sharing a frequency.

Everything Bill said, and I wouldn't put it past some RF-savvy FBI agents to have other fed channels in some zones that they could strap for encryption and pop up on for a quick mission and then disappear. I don't see why it would be an issue as encryption defeats monitoring, but if they were worried about being detected in the first place of being nearby with Quick Call, SDR RID tracking etc, popping up on a fire tac, outside of season, would be a decent cover to provide security by obscurity to the bad actors.

 

[ecps92]

IMHO you are not going to find "Federal LE" having FPP or "freq savy agency" adding channels.
Most radios are locked down with the multiple zones per MOU's and/or Dept channel plans.

A Radio Tech maybe, but not a field agent.

I would think, based on my East Coast [and times of travel] that there are still plenty of shared Frequencies
to be discovered, and with the NTIA pushing more to conform to the input/output/simplex plans, what used to be
"Exclusive" to one agency in a wide area is No more.

Just like Part 90 agencies looking at RailRoad, Part 22 and NTIA channels, the RF fight for spectrum continues.

Heck two examples from my back yard:

172.9000 which we all would assume is TSA [former FAA] is assigned to also ICE [yes same parent agency]
and then also re-use within monitoring distance of similar NACs - OPB in Maine using #00, but ICE in VT/NH also
using the same frequency and similar NAC pattern. Only way to know is start also logging RIDs

And unless any of us have access to Spectrum XXI - we will never know as hobbyists - all/most are assumptions
And YMMV is my favorite part of Federal Monitoring - you never, ever really know what you will find.

I now return us to DVP/DES mode

Everything Bill said, and I wouldn't put it past some RF-savvy FBI agents to have other fed channels in some zones that they could strap for encryption and pop up on for a quick mission and then disappear. I don't see why it would be an issue as encryption defeats monitoring, but if they were worried about being detected in the first place of being nearby with Quick Call, SDR RID tracking etc, popping up on a fire tac, outside of season, would be a decent cover to provide security by obscurity to the bad actors.

 

[ecps92]

Here are two non-parent agencies sharing from my back yard.

USFS input was also a near-by FBI input [same state, but far enough away and two different modes]
USFWS Repeater was also [neighboring state] using the same Freq as the input to an FBI Wide-Area net

Nothing is 100% single agency anymore

Are both the above true? I question the FBI & USFS sharing a frequency.

 

[norcalscan]

IMHO you are not going to find "Federal LE" having FPP or "freq savy agency" adding channels.
Most radios are locked down with the multiple zones per MOU's and/or Dept channel plans.

I agree and have had similar shared uses here in NorCal, where they stuck an FBI VHF P25 trunked control channel on the output of a USFS repeater 2 forests away, which wrecked havoc for any fire aircraft working the forest. Oops.

However I have read a fair share of radios off the hips and vehicles of our friends and I've been shocked to see what they had crammed in there tucked away for a rainy day. FPP no, but get a region that has a decent radio tech, treat them nice, and your radio may come back with a few extra "burner tacs"

Quick edit: in this particular case, with a non-fire agency on R5 Tac 5 in California, I can't see being a planned shared-use unless it was an absolute mistake. USFS fire tacs in California are gold they are so rare. The last thing those particular channels need is more interference and traffic during fire season. Off season - have at it. But in August those freqs are nearly slammed.