VHF radios - new licence conditions

[Scholar Gypsy]

I had an email from Ofcom recently, as I have licences for my VHF radios (and one for me to operate them too).   It refers to this page on their website, and proposed changes to licence conditions. https://www.ofcom.org.uk/manage-your-licence/emf

It's all a bit complicated, but I have looked through the pages and used the online calculator. My understanding is that: 

 

• no impact for handhelds, as they are below 10W. (I actually use an external microphone, which would reduce the risk even further)
• for typical marine VHF use (25 Watts, 150 Mhz or so),  the antenna should be at least 1.6 metres from any member of the public. 
• That term includes friends and family, but not the licence holder (who is apparently allowed to fry their own brain). Workers and employees are covered by other legislation. 
• I would intend to round the minimum distance up to 2 given how familiar we now are with that distance)
• The base station itself does not count as "equipment" - that's good - the radiation should come from the aerial not the base station.
• Emergency use is exempt.
• I have seen some installations where the antenna will need to be moved away from the steering position. My antenna is on a magnetic mount and on a long cable, and I  discourage people from sitting on the roof when on tidal waters. But some people I know mount their VHF radios on a breadboard, and they may need to procure a secondary breadboard. 
• I assume - does anyone know? - that I really don't need to bother about someone standing inside the boat under the antenna, as the large steel plate that forms the roof is a very effective reflector.  This wouldn't apply for boats with a wooden or tupperware roof, of course

 

Has anyone else looked at this? Any comments on the above? I should of course say that this is just my interpretation - no warranty is given!

[GUMPY]

Radiation is much lower when you are above or below the antenna. Imagine the antenna poking up through a ring doughnut the doughnut is the shape of the radiation pattern so very low immediately above or below the antenna.

Directional antennas are a whole different kettle of fish 

[Jen-in-Wellies]

The radiation pattern is concentrated in the horizontal plane, with little above and below, so people in a GRP cabin below will see a lot less energy than those close to it horizontally.

 

Post clash with @Loddon!

Edited March 7, 2021 by Jen-in-Wellies

[Scholar Gypsy]

1 minute ago, Loddon said:

Radiation is much lower when you are above or below the antenna. Imagine the antenna poking up through a ring doughnut the doughnut is the shape of the radiation pattern so very low immediately above or below the antenna.

Directional antennas are a whole different kettle of fish 

Thanks, yes that does ring a bell.....

[Jen-in-Wellies]

Having the steering position close to a high power aerial will help keep you warm during long chilly days at the tiller!

[Sea Dog]

This Radio Frequency radiation hazard is referred to as "RadHaz" in the forces. Usually, this is managed by  the affected area being out of bounds, some antennas have a yellow circle around them marking a 'safe' distance, often there's a '2 minutes in 20' zone to allow transit. To make servicemen take note of the unseen danger and follow necessary precautions, they're told it seriously affects the "family jewels" which, in truth, is quite a way down the list, but grabs the attention! Dunno what they tell the girls...

[Alan de Enfield]

3 minutes ago, Sea Dog said:

Dunno what they tell the girls...

 

Probably a good 'selling point' 

"Don't worry love, its quite safe I've been zapped by VHF"

[Sea Dog]

1 minute ago, Alan de Enfield said:

 

Probably a good 'selling point' 

"Don't worry love, its quite safe I've been zapped by VHF"

I meant servicewomen, although I suppose it also goes for testicular non-equipped service persons of whatever gender declaration they choose, whether or not they... oh, you know what I mean!

[Bee]

7 minutes ago, Alan de Enfield said:

 

Probably a good 'selling point' 

"Don't worry love, its quite safe I've been zapped by VHF"

Better than being zapped by STD

[Phoenix_V]

8 hours ago, Scholar Gypsy said:

I had an email from Ofcom recently, as I have licences for my VHF radios (and one for me to operate them too).   It refers to this page on their website, and proposed changes to licence conditions. https://www.ofcom.org.uk/manage-your-licence/emf

It's all a bit complicated, but I have looked through the pages and used the online calculator. My understanding is that: 

 

• no impact for handhelds, as they are below 10W. (I actually use an external microphone, which would reduce the risk even further)
• for typical marine VHF use (25 Watts, 150 Mhz or so),  the antenna should be at least 1.6 metres from any member of the public. 
• That term includes friends and family, but not the licence holder (who is apparently allowed to fry their own brain). Workers and employees are covered by other legislation. 
• I would intend to round the minimum distance up to 2 given how familiar we now are with that distance)
• The base station itself does not count as "equipment" - that's good - the radiation should come from the aerial not the base station.
• Emergency use is exempt.
• I have seen some installations where the antenna will need to be moved away from the steering position. My antenna is on a magnetic mount and on a long cable, and I  discourage people from sitting on the roof when on tidal waters. But some people I know mount their VHF radios on a breadboard, and they may need to procure a secondary breadboard. 
• I assume - does anyone know? - that I really don't need to bother about someone standing inside the boat under the antenna, as the large steel plate that forms the roof is a very effective reflector.  This wouldn't apply for boats with a wooden or tupperware roof, of course

 

Has anyone else looked at this? Any comments on the above? I should of course say that this is just my interpretation - no warranty is given!

The amateur radio fraternity never used to worry about this but now it is a big thing. Your interpretation is more or less what I thought, but should we put stickers on the boat not to stand near the aerial when transmission is likely or lines on the floor like railway platforms? what about pedestrians on the bank if antenna is on the side of the boat near the bank. It seems to be one of those rules that is only going to be enforced when someone sues you. A suitable risk assesment would be a good back covering exercise and just don't mention it to the bss people!

[Scholar Gypsy]

8 hours ago, Phoenix_V said:

The amateur radio fraternity never used to worry about this but now it is a big thing. Your interpretation is more or less what I thought, but should we put stickers on the boat not to stand near the aerial when transmission is likely or lines on the floor like railway platforms? what about pedestrians on the bank if antenna is on the side of the boat near the bank. It seems to be one of those rules that is only going to be enforced when someone sues you. A suitable risk assesment would be a good back covering exercise and just don't mention it to the bss people!

Thank you, that's interesting. I hadn't realised that amateur radio sets could be quite so powerful (2,250 W in Canada, 400W in the UK, according to Wikipedia). 

Edited March 8, 2021 by Scholar Gypsy

[Jen-in-Wellies]

There is only a hazard when transmitting. As inland boaters, that is for maybe 20 or 30 seconds in a typical conversation with another boat, or a lock keeper. That only happens when you are on few waterways where they are used. Perhaps only a few trips a year at most. This isn't like the radar transmitters on a navy vessel, blasting huge power out for long periods, hams with hundreds of Watts for hours on end. I have a lower powered hand held VHF radio. The amount of my brain that gets fried each year by it has to be vanishingly small. Or perhaps vanishingly small is a better description of my brain, in which case RF damage is a serious problem!. It isn't a risk I put an inordinate amount of worry in to.

 

Jen

Edited March 8, 2021 by Jen-in-Wellies

[peterboat]

16 hours ago, Sea Dog said:

This Radio Frequency radiation hazard is referred to as "RadHaz" in the forces. Usually, this is managed by  the affected area being out of bounds, some antennas have a yellow circle around them marking a 'safe' distance, often there's a '2 minutes in 20' zone to allow transit. To make servicemen take note of the unseen danger and follow necessary precautions, they're told it seriously affects the "family jewels" which, in truth, is quite a way down the list, but grabs the attention! Dunno what they tell the girls...

That it affects the family jewels is what they tell the ladies, I was in the Royal Signals when the combining of trades happened, I was still in when the WRAC was combined with the mens ARMY

[Mad Harold]

I had (have) a VHF operators licence which I obtained when I got my pilot's licence years ago. I seem to remember that the VHF licence was valid for life.

Can anyone confirm this? and also is this licence valid for marine VHF?

[Jen-in-Wellies]

3 minutes ago, Mad Harold said:

I had (have) a VHF operators licence which I obtained when I got my pilot's licence years ago. I seem to remember that the VHF licence was valid for life.

Can anyone confirm this? and also is this licence valid for marine VHF?

That it is for life is my understanding of the marine VHF license too. There is a responsibility to inform OFCOM of changes in address, equipment and so on as a result. The marine VHF license isn't valid for air use and I am guessing the opposite is true. Certainly the marine course I had to take was entirely nautical, with not a mention of air frequencies, etc.

[Scholar Gypsy]

20 minutes ago, Jen-in-Wellies said:

That it is for life is my understanding of the marine VHF license too. There is a responsibility to inform OFCOM of changes in address, equipment and so on as a result. The marine VHF license isn't valid for air use and I am guessing the opposite is true. Certainly the marine course I had to take was entirely nautical, with not a mention of air frequencies, etc.

And listening to ATC recordings (there's a fabulous youtube channel for this) I am glad marine uses numbered channels, rather than "Switch to Chicago Approach on 137.265" or whatever.

[ditchcrawler]

22 minutes ago, Scholar Gypsy said:

And listening to ATC recordings (there's a fabulous youtube channel for this) I am glad marine uses numbered channels, rather than "Switch to Chicago Approach on 137.265" or whatever.

When I did my restricted operators course many years ago there were two lads who were radio ops on a rig who had never had a licence but done the job for years so knew the lot, sat at the back.

The chap running the course was a long term Ofcom senior inspector. and when these two Charlie's came to do there bit pretending to talk to a land station he replied with listen for me on ( and reeled of a frequency not a number.) For some reason Mr. know it all's face changed somewhat.

[Alan de Enfield]

54 minutes ago, Mad Harold said:

I had (have) a VHF operators licence which I obtained when I got my pilot's licence years ago. I seem to remember that the VHF licence was valid for life.

Can anyone confirm this? and also is this licence valid for marine VHF?

 

No (at least that was what I was told when I did my course)

 

I was a ham (G3LCR) but still had to take my radio licence when I did my PPL, and neither my 'ham' licence or PPL licence was acceptable for the marine VHF.

 

 

Its a bit like the CRB checks.

When SWMBO was teaching riding, we both had to have CRB checks, when I was involved in Scouting I had to have another CRB (different discipline), when i was a Civilian Instructor in the RAF teaching cadets to fly I had to have another CRB check.

 

Crazy really as all a CRB check shows is that you haven't been 'caught' yet.

[ditchcrawler]

6 minutes ago, Alan de Enfield said:

 

No (at least that was what I was told when I did my course)

 

I was a ham (G3LCR) but still had to take my radio licence when I did my PPL, and neither my 'ham' licence or PPL licence was acceptable for the marine VHF.

 

 

I have an add on to talk to helicopters from the ground.

[Alan de Enfield]

5 minutes ago, ditchcrawler said:

I have an add on to talk to helicopters from the ground.

 

Yes, it all about specific frequencies and what you can use them for.

 

At least in Gliding we had ground to air frequencies  that could be used for starting comps, retrieval etc.

Retrieval used to 129.9 'in my day' but now with the 12Khz channel spacings they have additional channels with 129.905 being the main Ground to air.

 

Even with the new channel spacings 121.5 is still the International 'guard frequency'

Edited March 8, 2021 by Alan de Enfield

[Iain_S]

On 07/03/2021 at 14:26, Scholar Gypsy said:

I had an email from Ofcom recently, as I have licences for my VHF radios (and one for me to operate them too).   It refers to this page on their website, and proposed changes to licence conditions. https://www.ofcom.org.uk/manage-your-licence/emf

It's all a bit complicated, but I have looked through the pages and used the online calculator. My understanding is that: 

 

• no impact for handhelds, as they are below 10W. (I actually use an external microphone, which would reduce the risk even further)
• for typical marine VHF use (25 Watts, 150 Mhz or so),  the antenna should be at least 1.6 metres from any member of the public. 
• That term includes friends and family, but not the licence holder (who is apparently allowed to fry their own brain). Workers and employees are covered by other legislation. 
• I would intend to round the minimum distance up to 2 given how familiar we now are with that distance)
• The base station itself does not count as "equipment" - that's good - the radiation should come from the aerial not the base station.
• Emergency use is exempt.
• I have seen some installations where the antenna will need to be moved away from the steering position. My antenna is on a magnetic mount and on a long cable, and I  discourage people from sitting on the roof when on tidal waters. But some people I know mount their VHF radios on a breadboard, and they may need to procure a secondary breadboard. 
• I assume - does anyone know? - that I really don't need to bother about someone standing inside the boat under the antenna, as the large steel plate that forms the roof is a very effective reflector.  This wouldn't apply for boats with a wooden or tupperware roof, of course

 

Has anyone else looked at this? Any comments on the above? I should of course say that this is just my interpretation - no warranty is given!

Pretty much as I understand it, but you have to account for antenna gain at your second point, although this is only really relevant if there is little or no vertical separation between antenna and people, as would be the case with a roof mounted aerial on a narrowboat.

[Scholar Gypsy]

The RYA have issued some guidance, which reinforces much of the above. I sense they are a bit annoyed with Ofcom ...

"We are now aware that simultaneously, OFCOM contacted all licensees to tell them that they are varying the terms and conditions of their licences. The guidance is written in broad terms and is primarily aimed at mobile phone network operators; however, it applies equally to marine licensees. It is clear to us that this has caused considerable disquiet, not least because licensees are struggling to unravel the technical jargon and therefore the details of how to comply is far from clear."

https://www.rya.org.uk/newsevents/news/Pages/ofcom-introduces-new-licence-requirements-for-limiting-exposure-to-electromagnetic-fields.aspx?fbclid=IwAR0n8CK2TMClnSMCngNCrX42DLfYZJDDPV20HVKT3VdmLrKtUDuHAKGVSjA

[Iain_S]

The RSGB have done an Excel calculator, accessed from a few paragraphs down this page.

 EM Field Exposure - Radio Society of Great Britain - Main Site : Radio Society of Great Britain – Main Site (rsgb.org)

 

It incorporates the Ofcom calculator and applies corrections for duty cycle, co-ax loss, antenna gain, etc to the EIRP figure.

[Scholar Gypsy]

1 hour ago, Iain_S said:

The RSGB have done an Excel calculator, accessed from a few paragraphs down this page.

 EM Field Exposure - Radio Society of Great Britain - Main Site : Radio Society of Great Britain – Main Site (rsgb.org)

 

It incorporates the Ofcom calculator and applies corrections for duty cycle, co-ax loss, antenna gain, etc to the EIRP figure.

Thanks, that is interesting.  Putting in a realistic figure for average transmission over a 6 minute period (say 10%, and even that will be on the high side) results in a much shorter distance (0.5m for my setup, with a 5 metre coax).