What's with the "B" Channels?

[eriepascannist]

I was reading someone's webpage this evening on QSL, and they mentioned "B" (Bravo" channels in the marine spectrum. The author believed that these channels were illegal.

I have heard of "A" channels (quite common in the nearby Canadian Coast Guard that I monitor) but never "B" channels. I'm not looking to monitor or use anything illegally, I'm just curious what these channels are and what type of traffic they hold.

 

[SCPD]

"A" Channels are simplex on the "ship" side of a duplex channel where the "B" channels are simplex on the coast station side.

 

[nd5y]

Some of the VHF marine channels have two frequencies. Originally it was for full duplex telephone use. Some of the channels were split up. for example:
Ch 83 tx 157.175, rx 161.775
Ch 83A tx 157.175 rx 157.175
Ch 83B tx 161.775 rx 161.775
Some of the B channels are used for weather boradcasts in Canada. They may have different uses in other countries. That's about all I know.

See the chart at Marine VHF Channel Version Comparison Chart - The RadioReference Wiki

 

[W6KRU]

Tom and Jimmy already covered it pretty well but here is a link with more explanation: Marine Radio Scanning

And here is a chart with the full list: The 'Missing' Marine Channels

 

[eriepascannist]

Thanks for the replies, folks.

So the only use for these "B" channels is when there are the ship/base duplex freqs? I don't know what this QSL writer was talking about, but this makes sense. I was picturing this whole under-the-radar radio network that noone talked about on their marine freq pages...

I did know that internationally, there are some "B" channels used, but as for in the US it looks to me like there are very few, and they are just in the duplex freqs as the previous posters described.

 

[W6KRU]

Yeah unless you are a fisherman who wants a secret channel for you and your buddies. Then you can install an international radio and ???? I have even seen a few reports of them using amateur radios for secret channels out here on the west coast.

 

[eriepascannist]

Thanks for the info. My biggest thing was just to figure out what "B's" were and if I was missing out on interesting radio traffic. Being a radio enthusiast I can't stand the thought of freqs that have interesting coms that I'm not listening to...

Anyway it doesn't sound like I'm misssing much. Thanks again!

 

[novascotian]

Thanks for the info. My biggest thing was just to figure out what "B's" were and if I was missing out on interesting radio traffic. Being a radio enthusiast I can't stand the thought of freqs that have interesting coms that I'm not listening to...

Anyway it doesn't sound like I'm misssing much. Thanks again!

If you are in a good receiving area you should be able to hear the Port Burwell remote transmitter for Sarnia Coast Guard Radio. It broadcasts continuously on 161.65 Channel 21B. There is another one farther along the Erie shore at Leamington with the same broadcast on 161.775 Channel 83B. Because these only use the B side of the channels they call them 21B and 83B. There isnt any two way traffic on them at all. By the way there are a couple of other channels used like this in some parts of Canada in places where there is frequency congestion, or where there is a separate French language broadcast, but 21B and 83B are by far the most common ones. I know you wouldn't be too interested in listenign to the weather and notices to mariners from the Canadian side but they might serve as good indicators of listening conditions because they are always transmitting.

 

[eriepascannist]

Thanks I gave those a try and I can hear both from my location. Interesting- not something I would scan all the time, obviously, but cool to tune into nonetheless.

 

[AF0DJ]

Then you go up on Lake of the Woods, Ontario, Canada and chan 25 is a repeater channel.