# Silence Periods



## david.hopcroft (Jun 29, 2005)

It would seem that Silence Periods are no longer observed on 2182.

I have just been QSX 2182 and at 1931z Aberdeen CG comes up announcing Marine Info QSW etc.... This seems to happen quite regularly. 

David
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## sparkie2182 (May 12, 2007)

Reminiscences of a byegone era , David.

This is the way it is all done now........

http://www.gmdss.com.au/requirements.htm


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## david.hopcroft (Jun 29, 2005)

I live by the coast, so watch AIS sites. I am by no means a regular viewer but I get an impression that some ships appear to 'fall off' the screen in areas I would have thought were well covered by VHF. 

During a period of High Pressure, I heard St Johns CG Radio on 2182 at about 1930z. This shows how quiet it is these days. I only used to hear them on nights at a CRS.

David
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## Troppo (Feb 18, 2010)

Yep...no more SP on 2182...


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## Ron Stringer (Mar 15, 2005)

For ships involved in the GMDSS, 2182kHz is no longer an alerting frequency, but a distress communication frequency i.e. used for voice communications following the transmission and receipt of an alert. In the 2MHz band, calling and alerting is performed by DSC (digital selective calling) techniques on the frequency 2187.5kHz. Watchkeeping on that frequency is automated, by a dedicated DSC watchkeeping receiver.


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## david.hopcroft (Jun 29, 2005)

We took part in early trials of DSC at GKZ. Our Marconi H1000 reserve Tx was modded for 2187.5. The results were very good. I had a monitor in my office and was impressed. Never got as far as VHF though.

Between GKZ and 2BA we had good continuous VHF cover, so why do ships bound south from the Humber disappear from AIS (marinetraffic.com) just south of the Inner Dowsing ? Also, there are never any vessels showing in the Wash ports.

Any ideas anyone ?

David
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