OfCom and Galloping Compliance

[zoidberg]

I've had an email from OfCom - I'm sure others have, too - regarding their new Compliance Regime. Some of it here :

Guidance on EMF compliance and enforcement There is a .pdf file - Appropriate Records Demonstrating Compliance - and it is, of course, not a small one.

Is this another example of 'Proliferating Administratium', or a Solution to a Problem We Didn't Have?

 

[JumbleDuck]

There is some discussion of this on Scuttlebutt. I don't think it will be an issue for any normal installation. 25W voice through a whip at the masthead will be fine and 5W AIS through a stubby on the rail will be fine.

 

[zoidberg]

Aye, well, but. We'll still have jobsworths wandering about from time to time demanding Records of Compliance. I trust they'll have learned to swim.

 

[Never Grumble]

5W AIS through a stubby on the rail will be fine.

How did you calculate that? Asking for a friend.

 

[Aurai]

The flow chart provided, starts with radio equipment authorised to operate over 10W EIRP.

 

[TernVI]

The flow chart provided, starts with radio equipment authorised to operate over 10W EIRP.

Which would include a 5W transmitter with a 3dB gain antenna.

But EIRP is a far field concept, EMF is a near-field problem.

First impression is that it's a bunch of gibber written by a committee, but I haven't looked at it closely yet,

HTHBIDI.

 

[st599]

Which would include a 5W transmitter with a 3dB gain antenna.

But EIRP is a far field concept, EMF is a near-field problem.

First impression is that it's a bunch of gibber written by a committee, but I haven't looked at it closely yet,

HTHBIDI.

Their calculator hasn't helped by calling it "Transmitter Power (EIRP)".

 

[Slowboat35]

File under circular...

 

[Baddox]

All the info I have read says that AIS broadcasts with 2W of power. Dropping that into the OCOM calculator without factoring in gain, gives a safe working distance of 45cm.

 

[PaulRainbow]

All the info I have read says that AIS broadcasts with 2W of power. Dropping that into the OCOM calculator without factoring in gain, gives a safe working distance of 45cm.

Newer (SOTDMA) AIS transmit at 5w

 

[tillergirl]

Newer (SOTDMA) AIS transmit at 5w

Mine is. Since it is squawking all the time, I hope a metre is a safe working distance. If not I need to have a taller gantry!

 

[JumbleDuck]

How did you calculate that? Asking for a friend.

Their spreadsheet give 0.3m.

My general point was that there is a very limited range of powers (1, 5, 25W), antennas (whip, stubby) and locations (masthead, rail) on a sailing yacht, or on most sailing yachts, so we won;t have to do individual calculations.

 

[JumbleDuck]

All the info I have read says that AIS broadcasts with 2W of power. Dropping that into the OCOM calculator without factoring in gain, gives a safe working distance of 45cm.

Remember that Class B only broadcasts for 26.6ms every 30 seconds.

 

[PaulRainbow]

Remember that Class B only broadcasts for 26.6ms every 30 seconds.

SOTDMA class B can transmit at 5 second intervals for faster vessels.

 

[Hoolie]

The Ofcom EMF requirements are based on mean power; so 26.6ms per 5 seconds for a 5W device is about 27mW. Well below the 10W threshold the new regulations will apply to.

More applicable is a 1.01metre safe distance for a 9GHz 50W mean power radar and 1.6 metres for a 25W VHF - both calculated using the spreadsheet provided. Taking a point from an earlier post it's completely irrelevant whether the spreadsheet is correct or applicable, as that is what Ofcom will use to determine compliance

 

[rogerthebodger]

I think you will find that any state organ will look for new ways to increase it income due to the general loss of income as a result of the lockdown and lower taxation income.

I had a radio survey that was interduce and the survey confirmed the satisfactory operating of equipment that I did not have and the satisfaction operation that I have not turned on.

My ship registration number was not even entered on the the report / certificate

 

[JumbleDuck]

More applicable is a 1.01metre safe distance for a 9GHz 50W mean power radar and 1.6 metres for a 25W VHF - both calculated using the spreadsheet provided. Taking a point from an earlier post it's completely irrelevant whether the spreadsheet is correct or applicable, as that is what Ofcom will use to determine compliance

I really don't thnk we will have to bother individually. Either every single yacht with a 25W VHF and masthead whip antenna will be fine or every single one will fail. We'll know soon enough. I wonder if it will affect motorboaters more - they seem to love having lots of antenna, including whatever lives inside those dome things, mounted relatively low down.

 

[st599]

I really don't thnk we will have to bother individually. Either every single yacht with a 25W VHF and masthead whip antenna will be fine or every single one will fail. We'll know soon enough. I wonder if it will affect motorboaters more - they seem to love having lots of antenna, including whatever lives inside those dome things, mounted relatively low down.

There might be an issue if you dry out next to a quay somewhere with a big tidal range, or are in a lock. The main thing seems to be to consider it and keep note of how you worked it out.

The dome sometimes contains a gimballed satellite TV dish.

 

[Keith-i]

It does annoy me that they suggest we use the spreadsheet calculator then print out a copy to prove compliance yet the spreadsheet isn’t designed for printing as it spills across 4 pages ☹

 

[JumbleDuck]

There might be an issue if you dry out next to a quay somewhere with a big tidal range, or are in a lock.

Perhaps, but the calculations will apply to us all. I'm pretty sure that either my fixed VHF of GPS actually has a warning about not operating with humans within x metres of the antenna, but the manuals are on the boat which is 100 miles and a pandemic away.