Re: Ship test
Hello Brian,toggle quoted messageShow quoted text
To answer your specific question about Solent and Dover - they don't answer DSC calls on 2187.5kHz for the simple reason that they are not equipped with MF DSC!
Currently the only UK Coastguard Stations which will respond MF DSC are:
Milford Haven 002320017
Of these :
1) Clyde itself no longer exists, and calls to its MMSI are responded by the DSC System in the "North West" quadrant - shared between Belfast and Stornoway.
2) Brixham and Swansea no longer have their own MF equipment and calls addressed to their MMSIs are responded by the DSC system in the "South West" quadrant - shared between Falmouth and Milford Haven
The fact that Clyde has closed down, and this fact has been published in "Notices to Mariners" doesn't seem to have stopped the continued use of it's MMSI by Ships - they seem very slow to catch on sometimes!
Solent and Dover are only active on VHF DSC - Channel 70, 156.525MHz.
To answer your more general question about Ship tests not being responded to by Coast Stations, I think there are 3 possibilities:
1) The Coast Station addresses is out of range of the Ship and doesn't receive the test call - either due to propagation issues, or that fact that the coast station is very far out of range, and the call is sent more in hope than expectation (the "DXing Radio Officer" syndrome)
2) The Coast Station receives, and replies, but is out of range of you, and you don't hear the reply.
3) The Test Message is addressed to a Coast Station that is not active on the DSC channel concerned.
Of these, number 3 is very, very commonly seen!
Often a ship will send a test call to the same MMSI on ALL channels - 2/4/6/8/12/16MHz, yet the particular Coast station is only active on perhaps 2MHz or 8MHz.
Perhaps for simplicity the ship sends calls to the same MMSI on VHF and MF, despite the Coast Station being VHF only, such as the Solent/Dover example.
I regularly see calls on 8MHz addressed to UK Coastguard stations, despite the fact the the UK Coastguard are not, and have never been, active on HF!
How about we have a game - report the silliest Ship to Shore Test call we see - taking into account the time of day, frequency, location of the vessel and the location of the Coast Station being called, and the published capabilities of the Coast Station?
Seeing a Ship in the Baltic call RCC Australia on 2MHz in the daytime would score highly - 1) 2MHz won't propagate well over that distance in daylight and 2) RCC Australia doesn't have 2MHz DSC capabilities!
You ask about Voice Call tests too...
Coast Stations (in fact all stations) are still required to maintain a listening watch on VHF Channel 16 and voice calls for radio tests on Channel 16 will be responded to.
VHF DSC doesn't have a "TEST" funfion, unlike MF/HF DSC, so the weekly required DSC Check is done by initiating a DSC call to a Coast Station, on VHF CH. 70, followed by a voice call, either on Ch. 16 or on whatever channel is requested by the receiving Coast Station, during which they can verify that the DSC Message was received.
MF DSC has a "Test" facility, and many Coast Stations are set up to respond automatically, with no operator intervention, to such TEST calls.
Since the introduction of GMDSS it is no longer a requirement to maintain a listening watch on 2182kHz - but a few UK Coastguards do so - as long as they ensure that at least one of their MF sites is tuned to 2187.5kHz DSC. You might hear a few 2182kHz SSB test calls, but they are diminishing over time, as DSC becomes the dominant method of raising a Coast Station.
On 23/02/2014 08:27, jillxbrian@... wrote:
Hi all. Log overnight only of the usual suspects so didn't think you would be interested, but here's a question instead.