I just started monitoring the new US Capitol Police VHF P-25 trunked system that should replace the analog VHF conventional channels that are currently in use.
Here is what the system that is on the air is showing for details at this time:
SYS ID - 582
SITE NAC - N580
SITE - 001
WACN - BEE00
173.1625
173.8125
173.4750
170.5750
No affiliations or channel grants are being shown right now, as previous new reports were that the system is on line for coverage testing.
THE FED FILES - Welcome to The Fed Files blog! This blog was originally built to support the "Fed Files" column in Monitoring Times magazine. Although the Fed Files, as well as Monitoring Times, ended with the December 2013 issue, this blog continues and is associated with the new federal monitoring column, Federal Wavelengths, in The Spectrum Monitor magazine. If you would like to make a comment, pass along a tip or frequency you can send it to my email address, chrisparris @ thefedfiles.com
Pages
▼
Thursday, November 21, 2013
Wednesday, November 20, 2013
Coast Guard Data Bursts?
I have recently seen complaints from multiple locations about hearing some sort of digital noise or interference on the Coast Guard primary air operations frequency of 345.0 MHz. I thought I was not hearing it myself, but I set up one of my tunable wide-band receivers on this frequency and did hear it clearly when I opened the receiver squelch all the way.
What I am hearing is a series of short bursts of noise, almost like a burst of machine gun fire. The length seems to be from 4 to 6 "bursts" in a group, although some have been two groups of 4 or more in a row. I can also heard weaker stations followed by bursts from stronger stations. Sometimes the bursts are at a moderate tempo, and some seem to be very rapid compared to others.
Here are some short clips of what I heard. Turn the volume up when watching these:
At first I wasn't sure if these noises were intentional or just some form of interference, but after hearing them and listening to the patterns, I am guessing they are intentional usage of the frequency by the Coast Guard. As to what this is used for and why they are using this frequency remains a mystery. Anyone want to guess at what's going on here?
What I am hearing is a series of short bursts of noise, almost like a burst of machine gun fire. The length seems to be from 4 to 6 "bursts" in a group, although some have been two groups of 4 or more in a row. I can also heard weaker stations followed by bursts from stronger stations. Sometimes the bursts are at a moderate tempo, and some seem to be very rapid compared to others.
Here are some short clips of what I heard. Turn the volume up when watching these:
At first I wasn't sure if these noises were intentional or just some form of interference, but after hearing them and listening to the patterns, I am guessing they are intentional usage of the frequency by the Coast Guard. As to what this is used for and why they are using this frequency remains a mystery. Anyone want to guess at what's going on here?
Sunday, November 17, 2013
State Department 409.5250 MHz Work in LA
While in the Inland Empire near LA, I caught someone doing some work on the State Department's Diplomatic Security Service (DSS) repeater on 409.5250 MHz, N293. Besides a test tone, they were looping a test audio track of a man and a woman reading sentences that test the readability and the quality of the digital encoding & decoding. You can hear some of the errors that occurred while I was monitoring.
Eventually it sounded like they got the errors to a minimum, at least by listening to the audio tests. This went on over a couple of days this past week.