Marine noises
- Thread starter BillQuinn
- Start date
- Status
ka3jjz
Wiki Admin Emeritus
Bill which 'marine freqs'? There are 2 channels that are used for AIS (channels 87 and 88), and for which there's software so it can be copied. Be more specific.
73s Mike
73s Mike
Last edited:
baybum
Member
This looks like what you might be hearing...
http://www.coaa.co.uk/shipplotter.htm
AIS is a system that ships use to communicate their positions to each other as part of the global maritime safety system. From December 2004, all ships over 300 tons must carry an AIS system which broadcasts information about the ship to any suitably equipped receiver. AIS uses very short bursts of high speed data on two VHF channels in the marine band. The two frequencies used are 161.975 (Marine ch 87) and 162.025 (ch 88) MHz. Ships broadcast their identity, position, course, speed and destination so that other ships can take account of their movements. Using a low cost radio scanner tuned to one or other of these channels and ShipPlotter software running on your PC, you will be able to see a radar-like real-time map (below) of all the large ships manoeuvring in your area together with information about their destination, estimated time of arrival and even the dimensions of each vessel.
http://www.coaa.co.uk/shipplotter.htm
AIS is a system that ships use to communicate their positions to each other as part of the global maritime safety system. From December 2004, all ships over 300 tons must carry an AIS system which broadcasts information about the ship to any suitably equipped receiver. AIS uses very short bursts of high speed data on two VHF channels in the marine band. The two frequencies used are 161.975 (Marine ch 87) and 162.025 (ch 88) MHz. Ships broadcast their identity, position, course, speed and destination so that other ships can take account of their movements. Using a low cost radio scanner tuned to one or other of these channels and ShipPlotter software running on your PC, you will be able to see a radar-like real-time map (below) of all the large ships manoeuvring in your area together with information about their destination, estimated time of arrival and even the dimensions of each vessel.
aaronp
Member
- Joined
- Aug 21, 2005
- Messages
- 61
- Reaction score
- 0
Nope, I'll bet I know what they are talking about.
Does it sound like shhhhhhhhhhh then you hear beep beep beep and it disappears?
Were you anywhere near the border of Cecil County?
I keep hearing interference on my Marine radio. It occurs on Marine 16, 9, and 70 (probably others, but those are the only ones I really monitor).
Imagine you are out on the boat, and the interference hasn't caused you to turn off your radio yet. You hear "Pon Pon Pon Pon - This is the United States Coast Guard Urgent marine broadSHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH beep beep beep". And you sit there wondering what the Coast Guard was trying to tell everyone.
I've listened to Cecil County's trunked EDACS ProVoice system on an analog radio, and I'm convinced that it is the one causing the interference (if not, they sound the same). It doesn't sound like the control channel (constant), it sounds like one of the trunked voice channels (comes and goes as the channel is being used).
I've monitored it on 3 different marine radios (very expensive commercial grade, not so expensive consumer grade, and an Icom handheld). I could hear it on all three. It comes in so strong that the squelch can't silence it all the way up.
Is that what you are talking about?
Cecil County's trunked system is on 154 and 155 Mhz
http://www.radioreference.com/modules.php?name=RR&sid=2672
Does it sound like shhhhhhhhhhh then you hear beep beep beep and it disappears?
Were you anywhere near the border of Cecil County?
I keep hearing interference on my Marine radio. It occurs on Marine 16, 9, and 70 (probably others, but those are the only ones I really monitor).
Imagine you are out on the boat, and the interference hasn't caused you to turn off your radio yet. You hear "Pon Pon Pon Pon - This is the United States Coast Guard Urgent marine broadSHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH beep beep beep". And you sit there wondering what the Coast Guard was trying to tell everyone.
I've listened to Cecil County's trunked EDACS ProVoice system on an analog radio, and I'm convinced that it is the one causing the interference (if not, they sound the same). It doesn't sound like the control channel (constant), it sounds like one of the trunked voice channels (comes and goes as the channel is being used).
I've monitored it on 3 different marine radios (very expensive commercial grade, not so expensive consumer grade, and an Icom handheld). I could hear it on all three. It comes in so strong that the squelch can't silence it all the way up.
Is that what you are talking about?
Cecil County's trunked system is on 154 and 155 Mhz
http://www.radioreference.com/modules.php?name=RR&sid=2672
organized_mayhem
Member
Does anyone know if anyone has been contacted about this? It seems like its getting worse at times.
The Interference is Cecil County
It has been noted to cause interference not only on Marine Band but also Railroad Band but other Public Safety Bands. From what I understand the FCC has been notified and Cecil County has been told to correct the problem. I dont have any other information on this.
It has been noted to cause interference not only on Marine Band but also Railroad Band but other Public Safety Bands. From what I understand the FCC has been notified and Cecil County has been told to correct the problem. I dont have any other information on this.
organized_mayhem
Member
Maybe its time for more complaint letters
Joseph11
Member
- Joined
- Nov 17, 2004
- Messages
- 2,270
- Reaction score
- 3
I live up in New Jersey and when I'm able to hear the Cecil County, MD EDACS system via tropo on my scanner, the voice channels and control channel bleed like crazy into other frequencies near by. It gets pretty bad, at times. I guess for the locals it's much worse.
It seems as though, considering the Cecil TRS is using VHF splinter and digital modulation, they should be using narrow band, so bleed to adjacent frequencies should be minimal, especially when other users are using medium to high-grade equipment. Heck, most of these frequencies people are getting bleed on aren't even "adjacent"... I'd guess that Cecil simply "cranked" up the wattage in a febile attempt to solve their disastrous coverage issues!
aaronp
Member
- Joined
- Aug 21, 2005
- Messages
- 61
- Reaction score
- 0
I was out on my boat this weekend, and for the first time this summer noticed that the interference was gone.
Maybe the "right people" were notified...
Of course this allowed me to hear all of the idiots asking for radio checks on 16.
Hello watchdeskers!
http://www.thewatchdesk.com/forum/showthread.php?t=34078
Maybe the "right people" were notified...
Of course this allowed me to hear all of the idiots asking for radio checks on 16.
Hello watchdeskers!
http://www.thewatchdesk.com/forum/showthread.php?t=34078
organized_mayhem
Member
aaronp said:
Yes it was. Very strongly i might add.
- Status
Similar threads
