Question about Ch 16

[boristhebold]

Was out and about on Monday in Poole Bay, I noticed some numpty head had an open mic on channel 16 for a good few hours, sounded like they were chatting away in the background making their dinner. Apparently it was in the christchurch area somewhere.

So my question is what is the impact of an open mic, I know it stops us hearing things but does it also stop the coastguard / rnli etc, does it stop us being able to transmit on that channel. Can anyone explain better to me what happens.

[Polwart]

My understanding is the strongest signal will overpower all the others. So yes it can potentially wipe out quite a big area for quite some time. A number of radio manufacuturers have systems in place to stop you accidentally locking the mike on for long periods (so say after 10mins of transmit it just stops).

[9D280]

Potentially drown out a Mayday shout....

It's the same reason when you call someone on CH16 the first thing you do is agree what channel you are going to switch to, the second being to switch to a working channel!

It's related to one of the good things about MMSI "direct dial" - it doesn't clog 16.

[Anchorhandler]

Sadly we suffered a problem last week on ch12.....for about 1.5 hours all we could hear were dogs barking????

Although Coast Guard and VTS still only transmit at 25w, they generally have some pretty big, high gain, low loss 'sticks' to help broadcast the message.

It would be difficult for a leisure boat vhf set to drown out the CG or VTS, especially if they are close to shore. Offshore and you happen to be on the threshhold for range of a CG broadcast station then somebody nearby with an 'open mic' could very well cause you problems.

I'm always dismayed at how many times we hear children messing about with a VHF set sometimes (but luckily rarely) for hours. Bring back electro-shock therapy!

Simon

[boristhebold]

Thanks that makes sense. At the bournemouth airshow I heard some muppets singing a song on channel 16, the coastguard was not amused.

[m chappelow]

in some cases the m.c.a (coastguard) will ask a lifeboat if its fitted with D/F (direction finding equipment ) to try locate the vessle or set,

one of our local fishing boats had the skipper squeeze the mike so hard that the switch stuck on transmit ,,unbeknown to him all we could hear for about 2 hours were the sound of a single cylinder diesel engine and the crew slagging all the other local fishing boats off that they came across ,,,bit embaressed when they finally got back to shore and realised what had happened ,,lol

[willk]

Originally Posted by boristhebold

I heard some muppets singing a song on channel 16, the coastguard was not amused.

Not entirely relevant, but recently I heard Belfast CG calling a test MAYDAY on 16 when they meant to make it on 0. Clyde CG were not amused. P&O Highlander was not amused. Few redners all round....

[Ian M]

Many years ago (but not THAT many) we used to have female divers on the club dive boat One of these beauties decided that it was too hot for her to be wearing a woolly hat, so she stuffed it into a gap in the console, directly above the mike You guessed it.................. for 10 minutes we were transmitting on 16. Fortunately one of the more intelligent (male) members of the crew spotted it and it was discretely removed. Thankfully nothing had been said that identified us Oh the shame

[SPR]

I believe that DF equipment have been removed from coastguard ststions .. so need to task two resources now:

House of Commons - Transport Committee - Written Evidence

S.

[SPR]

Originally Posted by 9D280

It's related to one of the good things about MMSI "direct dial" - it doesn't clog 16.

But DSC Distress or Urgency will switch all radios to ch.16 after the Digital message is sent on ch 70

So still pita if somebody is jamming 16 , although they might notice if its DSC Radio bleeping ...

S.