Changes to VHF licence

[Bilgediver]

I've watched this saga unfold. I'm trying to reduce the headache to what I need to do as a sailor and forget the empire-building.

I've done the calculations for my boat. I have AIS, VHF and Radar.
By my understanding, I enter 25W (VHF) + 5W (AIS) + 20W (radar) in the spreadsheet. For my installation, I use a splitter on the VHF aerial so you can't in reality use AIS and VHF simultaneously, but never mind. I then ran the calculation for the lowest frequency at(155Mhz)and highest at (9446Mhz) and took the worst-case scenario. The output was 2.26m in my case. Can anyone tell me if this is right, or am I off base?

Now just have to put up the warning signs to keep THE PUBLIC on board safe

 

[madabouttheboat]

Average boat owners are not the primary audience for these measures; they are are for everyone who who is licensed to use the radio spectrum - so all the Telcos, broadcasters, taxi companies, anyone using RF to transfer data from remote sites, microwave communications, ham radio, and so on.

I do understand that, but I have been sent the email and i'm just an average boat owner. I have been sent it purely becasue I have a VHF licence onboard a boat. Perhaps they should have written a few different emails more suitable for the target audience. How hard would it be?

Nice website BTW

 

[agurney]

I do understand that, but I have been sent the email and i'm just an average boat owner. I have been sent it purely becasue I have a VHF licence onboard a boat. Perhaps they should have written a few different emails more suitable for the target audience. How hard would it be?

Nice website BTW

Ofcom knows my boat's callsign and MMSI, but I don't recall ever telling them if she is a sloop, cargo vessel, hovercraft or tanker.

 

[awol]

There you go!

 

[longjohnsilver]

Average boat owners are not the primary audience for these measures; they are are for everyone who who is licensed to use the radio spectrum - so all the Telcos, broadcasters, taxi companies, anyone using RF to transfer data from remote sites, microwave communications, ham radio, and so on.

I guess you’re correct in what you say. But if so, why on earth didn’t Ofcom make that clear in their jargon ridden email?

 

[Boathook]

I emailed ofcom about about the spreadsheet,etc and saying that I just purchased kit, fitted using manufactures guides and just used it so could they simplify it!
I go a reply from them as below -

Thank you for contacting Ofcom.

Next week we are releasing some simpler guidance for the EMF changes. This is due to feedback received from customers like yourself, so please keep checking back to the EMF section of our website Electromagnetic fields (EMF)
These guides will be there to assist Maritime users and help with the various questions you have.
If you have any further queries please do not hesitate to contact the Spectrum Licensing Team on 020 7981 3131 or via email at spectrum.licensing@ofcom.org.uk.

Kind regards,

 

[Bilgediver]

I emailed ofcom about about the spreadsheet,etc and saying that I just purchased kit, fitted using manufactures guides and just used it so could they simplify it!
Kind regards,

I suspect their Inbox has been overflowing and not just from mariners

 

[Bristolfashion]

I agree with previous comments. There is so much standard type stuff on boats that a fairly simple set of guidelines could be issued - a good job for the PBO / RYA Texas others have said.

I'm not aware of a recreational boat ever being inspected for compliance.

 

[john0740]

I suspect many will find out the data isn't available. ...

An EIRP figure for the modern generation radar I have is not quoted in the manufacturer's literature, so naturally I emailed to ask. This radar does not create a power density of greater than 10W/m^2 at any point, so I don’t actually need further information. However, they expect to come back to me with further information which will be interesting.

I suppose that’s another advantage of the post-magnetron era radars.

 

[Daverw]

My B&G 4g spec states Transmitter peak power output 165 mW (nominal - at antenna port)
is that the same as EIRP?

 

[Seven Spades]

All we need is a standard list for each device onboard nd the we can cut and paste those bits of kit we have into a doc, print and laminate it.

25W Masthead VHF
5W Hand Held VHF
Epirb
PLB
Radar
Boat wifi
SSB

I can’t think of anything else. It would have been much better if Ofcom had simply required equipment manufacturers to include a sticker with each bit of kit sold that could be stuck either in a folder or put on display.

if there are any techies here who can do the calculations for the above and post them, we can all simply use the bits we need and go sailin.

 

[john0740]

All we need is a standard list for each device onboard nd the we can cut and paste those bits of kit we have into a doc, print and laminate it.

25W Masthead VHF
5W Hand Held VHF
Epirb
PLB
Radar
Boat wifi
SSB

I can’t think of anything else. It would have been much better if Ofcom had simply required equipment manufacturers to include a sticker with each bit of kit sold that could be stuck either in a folder or put on display.

if there are any techies here who can do the calculations for the above and post them, we can all simply use the bits we need and go sailin.

For a VHF installation, I don't think that this could be a 'standard list' item ...

Here's an example basic calculation I made to estimate for a VHF installation with the antenna at a yacht masthead. I have not allowed for connector losses nor averaged the power to take account of duty cycle.



Plugging in that 26.3W to the 'EMF spreadsheet' gives a separation distance of 1.7m.

For radar, the manufacturer should provide the necessary information.

Equipment used for emergency purposes is not covered so my interpretation is that an EPIRB and PLB would not be covered. Nor would a common VHF handheld since under 10W.

 

[Achosenman]

I suspect Ofcom will end up regretting they have opened this can of worms.

I went and checked my boat yesterday. The radar is 8m above the deck. The VHF, like most sailing yachts, sits on the masthead. I suspect we are more at risk from the microwave in the galley than anything else on board.

 

[st599]

My B&G 4g spec states Transmitter peak power output 165 mW (nominal - at antenna port)
is that the same as EIRP?

Nope, need to add in cable loss and antenna gain.

 

[TLouth7]

It's just Ofcom indulging in pointless box-ticking, and we're paying for it!

No we aren't!

How do we take into account that there is negative gain in the vertical direction for most kit? As in, I may need to keep a reasonable horizontal distance from my radar, but I should be able to get away with a smaller vertical distance.

 

[pvb]

No we aren't!

How do we take into account that there is negative gain in the vertical direction for most kit? As in, I may need to keep a reasonable horizontal distance from my radar, but I should be able to get away with a smaller vertical distance.

For years, recreational boaters have been using radars and radios. Generally speaking, they're sensible about it and don't put a radome next to their head. I've never heard of anyone being injured by radiation from a radome or a radio. So this current exercise is both box-ticking and arse-covering by Ofcom. And, yes, we are paying for it.

 

[Daverw]

Nope, need to add in cable loss and antenna gain.

Just had this pointed out from manual 1 mW/cm2, so not an issue for radar

 

[agurney]

For years, recreational boaters have been using radars and radios. Generally speaking, they're sensible about it and don't put a radome next to their head. I've never heard of anyone being injured by radiation from a radome or a radio. So this current exercise is both box-ticking and arse-covering by Ofcom. And, yes, we are paying for it.

Generally speaking, yes, they/we are sensible, but I've seen a few folks over the years getting a mouthful from lockkeepers in Crinan when boats are sitting in the sea lock with the radar on.

 

[Blue Sunray]

Generally speaking, yes, they/we are sensible, but I've seen a few folks over the years getting a mouthful from lockkeepers in Crinan when boats are sitting in the sea lock with the radar on.

I have also seen a few older flybridge and Dutch style motor boats with, to my mind, very poorly positioned radars, behind (in front in the Dutch style) and level with the helm's head.

 

[TernVI]

Nope, need to add in cable loss and antenna gain.

And the tolerance on transmit power?