Thursday, November 14, 2019

Another 380 MHz Trunked System and Garage Doors

Another story has  emerged about people having trouble with their garage door remote controls likely due to interference from a government 380 MHz trunked radio system:

https://www.fauquiernow.com/fauquier_news/article/fauquier-feds-admit-radios-interfere-with-garage-door-openers-11-5-2019

These systems have been blamed in other areas for causing issues, but since the garage door openers are FCC Part 15 devices, they have to accept any interference from licensed users. The door opener remotes are often built with poor selectivity and get de-sensed from the legitimate radio systems nearby.

Saturday, October 12, 2019

VHF P-25 DoD System Near Pittsburgh?

A recent posting over on Radio Reference indicates that a new VHF P-25 multi-site radio system is being heard in the Pittsburgh area, in southwestern Pennsylvania.

System information was posted as shown below:


Pittsburgh Area VHF P-25 DoD System?
Network: BEE00.8A8
Bandplan #4:
Base=136.
Offset=+0.9
Spacing=12.5
BW=12.5 
Site: 1.1 NAC=8A0
Neighbors: 1.2, 1.3, 1.4, 1.5 
Channel 4-179: 138.2375 CC 
Channel 4-215: 138.6875 CC SCC 

Site: 1.2 NAC=8A0
Neighbors:1.1, 1.3, 1.4, 1.5 
Channel 4-163: 138.0375 CC SCC 
Channel 4-205: 138.5625 CC SCC VOICE 
Channel 4-255: 139.1875 VOICE DATA 
Channel 4-495: 142.1875 VOICE DATA 

Site: 1.3 NAC=8A0
Neighbors: 1.1, 1.2, 1.4, 1.5 
Channel 4-181: 138.2625 CC 
Channel 4-217: 138.7125 SCC 
Channel 4-291: 139.6375 VOICE 
Channel 4-519: 142.4875 VOICE 

Site: 1.4 NAC=8A0
Neighbors: 1.1, 1.2, 1.3, 1.5 
Channel 4-203: 138.5375 CC 
Channel 4-243: 139.0375 SCC 

Site: 1.5 NAC=8A0
Neighbors: 1.1, 1.2, 1.3, 1.4 
Channel 4-201: 138.5125 CC 
Channel 4-219: 138.7375 CC SCC

Anyone have any information on the system being heard and where it might be?

There is already a VHF P-25 system at the Pittsburgh Air Reserve Station at the Pittsburgh International Airport. This system is part of a US Air Force system covering many bases:
Site 1-015
Pittsburgh Air Reserve Station  Allegheny, PA      
138.5875          
140.6625               
141.4875               
143.0125               
143.0625        
 
-->
-->

Tuesday, September 10, 2019

VHF Marine Channel Number Changes

The US Coast Guard has a nice chart of the numbering changes on some of the VHF marine radio channels used in the United States. Here is a link to the chart:

https://www.navcen.uscg.gov/?pageName=mtvhf

So why the changes? Here's an explanation from the Coast Guard:

Note that the four digit channel number beginning with the digits "10" indicates simplex use of the ship station transmit side of what had been an international duplex channel.  These new channel numbers, now recognized internationally, were previously designated in the US by the two digit channel number ending with the letter "A".  That is, the international channel 1005 has been designated in the US by channel 05A, and the US Coast Guard channel 1022 has been designated in the US as channel 22A.

Thursday, August 08, 2019

ELMR 14C Sites in Barstow CA


On a recent drive between Las Vegas and Burbank, I ran across two ELMR 14C sites in Barstow, CA supporting the Marine Corps Logistics Center there; https://www.mclbbarstow.marines.mil

The Radio Reference database has never shown any sites for Barstow, so these may be new.

Also, the 14C system has been undergoing upgrades to Phase II and some site number changes, so some of the data shown on Radio Reference is out of date.

Here are the PRO96COM logs - note that the two sites only show each other as neighbors. Both sites were showing a P-25 NAC of N14C;

System ID : 14C
System Name : DoD ENTERPRISE LM RADIO SYSTEM [ELMR]
WACN : BEE00
Tower Number (Decimal): 5-16
Tower Number (Hex) : T0510
Tower Description : SITE 05-016 BARSTOW CA
Control Capabilities : Data,Voice,Registration
Flavor : Phase 2
Call Sign(s) :
Timestamp : Mon Aug 5 12:18:54 2019

-Tables
#Format: Table ID,Base Freq,Spacing,Input Offset,Assumed/Confirmed,BandWidth,Slots
00,851.00625,0.00625,-45.00000,"Confirmed",0.01250,1
01,762.00625,0.00625,30.00000,"Confirmed",0.01250,1
02,380.00000,0.01250,10.00000,"Confirmed",0.01250,1
03,380.00000,0.00625,10.00000,"Confirmed",0.01250,2

-Frequencies
#Format: Channel,Usage,Frequency(/Slot),Input Channel,Input Frequency(/Slot),Input Explicit(1/0),Hit Count
"02-0428","c",385.35000,"02-0428",395.35000,0,0
"02-0473","a",385.91250,"02-0473",395.91250,0,0
"02-0558","v",386.97500,"02-0558",396.97500,0,2
"02-0640","vd",388.00000,"02-0640",398.00000,0,2
"02-0649","v",388.11250,"02-0649",398.11250,0,2
"02-0661","vd",388.26250,"02-0661",398.26250,0,1
"03-2597","v",388.11250/1,"03-2597",398.11250/1,0,1
"03-2644","v",388.26250/0,"03-2644",398.26250/0,0,1

-Neighbors
#Format: TowerID,TowerIDHex,System ID,Channel,Frequency,Tower Name
517,"T0511",14c,"02-0668",388.35000,""

System ID : 14C
System Name : DoD ENTERPRISE LM RADIO SYSTEM [ELMR]
WACN : BEE00
Tower Number (Decimal): 5-17
Tower Number (Hex) : T0511
Tower Description :
Control Capabilities : Data,Voice,Registration
Flavor : Phase 2
Call Sign(s) :
Timestamp : Mon Aug 5 12:20:39 2019

-Tables
#Format: Table ID,Base Freq,Spacing,Input Offset,Assumed/Confirmed,BandWidth,Slots
00,851.00625,0.00625,-45.00000,"Confirmed",0.01250,1
01,762.00625,0.00625,30.00000,"Confirmed",0.01250,1
02,380.00000,0.01250,10.00000,"Confirmed",0.01250,1
03,380.00000,0.00625,10.00000,"Confirmed",0.01250,2

-Frequencies
#Format: Channel,Usage,Frequency(/Slot),Input Channel,Input Frequency(/Slot),Input Explicit(1/0),Hit Count
"02-0580","v",387.25000,"02-0580",0.00000,0,0
"02-0590","vd",387.37500,"02-0590",0.00000,0,0
"02-0606","vd",387.57500,"02-0606",0.00000,0,0
"02-0614","vd",387.67500,"02-0614",0.00000,0,0
"02-0623","a",387.78750,"02-0623",397.78750,0,0
"02-0668","c",388.35000,"02-0668",398.35000,0,0
"03-2320","v",387.25000/0,"03-2320",397.25000/0,0,0
"03-2321","v",387.25000/1,"03-2321",397.25000/1,0,0
"03-2424","v",387.57500/0,"03-2424",397.57500/0,0,0
"03-2425","v",387.57500/1,"03-2425",397.57500/1,0,0
"03-2457","v",387.67500/1,"03-2457",397.67500/1,0,0

-Neighbors
#Format: TowerID,TowerIDHex,System ID,Channel,Frequency,Tower Name
516,"T0510",14c,"02-0428",385.35000,"SITE 05-016 BARSTOW CA"

Sunday, July 07, 2019

Providence, RI

Time for an update to the Fed Files blog!

I recently spent a few days in the downtown Providence area and had some interesting federal radio activity. Here are  few things I heard:

162.6125, N293  - VA Providence, repeater out. 
162.7000, N293 - Input to US Marshals Service 170.7500
163.0875, DCS 351 - VA Maintenance repeater out.
164.7000, DCS 023 - Automated alarm notifications - VA Telcom repeater out.
166.5000, DCS 351 - Input to VA Maintenance repeater.
170.7500, N293 - US Marshals Service Federal Courthouse
171.2375, N293 - US Coast Guard NET 127, Warwick, RI 
172.1500, N0D3 - TSA at PVD airport
173.2250, NXDN RAN 30, probably not federal, radio ID of 60991, talk group 20005, all ENC
406.1375, CC1 - DMR US Postal Service Capacity +
407.3375, CC1 - DMR US Postal Service Capacity +
408.2000, N201 - Federal Protective Service

Friday, April 12, 2019

US Miltary P25 Low Band Report

I have reported several sources indicating that they have heard some P-25 digital modes in to 30 - 88 MHz VHF low band that were assumed to be military. Some were with confirmed P-25 Network Access Codes (NAC), but I have recently heard a report of actual military activity using P25 digital.

From somewhere in Wisconsin:

40.4000 MHz, P25 NAC F7E - Military aircraft (helicopters) in the clear, base side encrypted

Some have asked how this can be, as none of the major equipment manufacturers make VHF low-band P-25 radios, at least not for civilian use. 

The major players in the military communications market (Harris, Thales, Motorola) all offer wide band, multi-mode radios that can be used in nearly any mode on any frequency. P-25 is an optional mode for these radios. 

It's still not known for sure if this is an intentional move to use P25 in the VHF low band, or just accidental programming of a particular channel.