OFCOM part 2

st599 said:
The General Public in EMF regulations are anyone who isn't trained in RF installations or the operator. So your crew count as General Public.
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Just tell them to stand back or go for a swim, while you press transmit :)

Plus you are exempt from all this nonsense if your average power is less than 10 w over a 6 minute period - how many leisure boaters exceed 10w average over 6 minutes? not many, unless you're broadcasting the shipping forecast. My transmitting use of the radio is typically less than 10 seconds asking the marina if someone could come to the fuel quay, or maybe 30 seconds asking which berth I am on for the night.

"When assessing whether equipment transmits at powers higher than 10 Watts EIRP (or 6.1 Watts ERP), spectrum users can take into account the average power12 of their equipment (provided their equipment does not transmit at a peak power13 higher than 100 Watts EIRP or 61 Watts ERP). 11 This may only apply to a limited amount of radio equipment such as EPIRBs (emergency position indicating radio beacons). 12 By ‘average power’ we mean the radiated power (EIRP or ERP) averaged over the relevant averaging period (e.g. 6 or 30 minutes). 13 By ‘peak power’ we mean the maximum instantaneous radiated power (EIRP or ERP).Version number 1.0 (effective 18 May 2021) 10 To calculate the average power of their equipment, spectrum users will need to know the maximum length of time14 that their equipment will transmit for in any six minute period.15 They can then enter this in Ofcom’s EMF calculator (along with the peak power of the equipment) and the calculator will calculate the average power. Spectrum users should make a conservative assessment of the maximum length of time that they transmit for in any six minute period. For example, if equipment is sometimes used continuously for six minutes at a time, then the user should enter a time period of six minutes in the calculator, even if the equipment is not used continuously throughout the day. If the result of the calculation shows that the average power is less than 10 Watts EIRP (or 6.1 Watts ERP), the spectrum user will not need to carry out an EMF assessment. However, they should still print off a copy of the average power calculation and keep this record with their licence document"
 
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Mr Googler said:
I think you need to have done the calculation and keep a record of it.

Belt and braces…a sticker somewhere saying ”stay x.xx metres away from this aerial”

One of these too perhaps

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Now I understand (y) Where do I get the sticker from?

Seriously, I still have no clue what I am supposed to produce. Mhz etc mean nothing to me. I use radio channels 16 and 77 possibly 65. When I'm chatting to the pirates I'm at 1 W or Low power and when on 16 it goes 25 W automatically unless I manually reduce power. The antenna base is 1m from my head on the radar arch (otherside and the radar arch is epoxy coated aluminium 1 foot wide - Faraday shielding?) and there is no other suitable place to put it.

Given those parameters what do I need to do?
 
BruceK said:
Now I understand (y) Where do I get the sticker from?

Seriously, I still have no clue what I am supposed to produce. Mhz etc mean nothing to me. I use radio channels 16 and 77 possibly 65. When I'm chatting to the pirates I'm at 1 W or Low power and when on 16 it goes 25 W automatically unless I manually reduce power. The antenna base is 1m from my head on the radar arch (otherside and the radar arch is epoxy coated aluminium 1 foot wide - Faraday shielding?) and there is no other suitable place to put it.

Given those parameters what do I need to do?
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Do you ever transmit at 25 watts for more than 2 minutes 23 seconds in any 6 minute period? If not just write down your average power calculation (9.99w per minute if you transmit at 25w for 2 minutes 23 seconds in a 6 min period )over 6 minutes and you're done - or more likely just ignore the email
 
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I hardly transmit at all. Maybe 20 seconds in a weekend. Usually to say goodbye to accompanying cruisers. Otherwise I dont use the radio at all and switch it off once at anchor because bizarrely the radio absolutely freaks the dog out. He goes into a nervous meltdown, hides in the mid cabin and pants and drools in terror.

And so, all I have to do is get a bit of paper and write

"9.99w per minute if you transmit at 25w for 2 minutes 23 seconds " stick it with my OFCOM license and I'm good?

Seems plausible

Havent a bloody clue what it actually means though.
 
BruceK said:
I hardly transmit at all. Maybe 20 seconds in a weekend. Usually to say goodbye to accompanying cruisers. Otherwise I dont use the radio at all and switch it off once at anchor because bizarrely the radio absolutely freaks the dog out. He goes into a nervous meltdown, hides in the mid cabin and pants and drools in terror.

And so, all I have to do is get a bit of paper and write

"9.99w per minute if you transmit at 25w for 2 minutes 23 seconds " stick it with my OFCOM license and I'm good?

Seems plausible

Havent a bloody clue what it actually means though.
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yep - thats my interpretation of it anyway , and I suspect thats how the new rules would apply to most leisure boaters, because who transmits for minutes at a time - its a quick 20-30 seconds at a time for most I guess.

Maybe your dog goes nuts because he hates EMF?
 
julians said:
you are not the general public - so you can fry yourself with as much EMF as you like, just make sure your wife/kids are not standing too close!


" It does not require spectrum users to protect any person from EMF exposure who is: a) the licensee, owner, operator or installer of the relevant radio equipment; or b) acting under a contract of employment or otherwise acting for purposes connected with their trade, business or profession or the performance by them of a public function. "
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Are you going to tell my wife that she is "General Public" - I'm not that brave!!
 
As I understand it, so long as you have either complied with the equipment installation instructions or have used the Ofcom calculater and can show compliance then you are fine. As with all these regulatory things, if asked just provide them with some evidence that you have tried to comply and half the battle is won. Keep the installation leaflet on the boat or a printed copy of the ofcom claculator results.

Interestinlgy most people seem to be referrring to 1.6m min distance for a 25w VHF. However, this doesn't take into account duty cycle which mitigates it quite a bit. See the below from Digital yacht's website regarding AIS. Duty cycle is also referenced on teh Ofcom calculator instructions.

The calculator will then give you the safe distance from the antenna which for a Class A AIS works out as 1.13m. This distance is further mitigated by the duty cycle of the transmission which is just a fraction of a second for an AIS transmission so the reality is a human can stand adjacent to an AIS antenna without issue
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julians said:
(9.99w per minute if you transmit at 25w for 2 minutes 23 seconds in a 6 min period )
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That's the power out of the radio, you need to do the calculation for the power out of the antenna - i.e. take account of the antenna gain and cable loss.
 
What about handhelds?? Do I need to tape this to a 1 meter long stick with some way of pushing the button??? This is over my head.
 
st599 said:
That's the power out of the radio, you need to do the calculation for the power out of the antenna - i.e. take account of the antenna gain and cable loss.
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Looks like the eirp of my radio, cable and antenna is ~49w (at full transmitter power of 25w) , which gives me about 1minute 10 seconds of transmit per 6 minutes to keep the average under 10w eirp. Thats fine for my use.
 
Hurricane said:
Yes - but what do they want me to do?
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I think they are telling us in their own oblique way that they want us to carry out a Risk Assessment and write down our results and and file it with our licence on board. In the event that we don't comply then we can use some of that left over covid tape to mark the areas of deck where public must keep clear of when we are transmitting using lots of welly. Clarity is not their thing.
 
Bilgediver said:
I think they are telling us in their own oblique way that they want us to carry out a Risk Assessment and write down our results and and file it with our licence on board. In the event that we don't comply then we can use some of that left over covid tape to mark the areas of deck where public must keep clear of when we are transmitting using lots of welly. Clarity is not their thing.
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Yep - I think I agree thats what they want.
It is a shame that they don't say so.
Some of my friends don't even know that they need a licence so "oblique" stuff like this doesn't help at all.
They need to be more specific so that anyone can understand what they want us to do.
 
julians said:
yep - thats my interpretation of it anyway , and I suspect thats how the new rules would apply to most leisure boaters, because who transmits for minutes at a time - its a quick 20-30 seconds at a time for most I guess.

Maybe your dog goes nuts because he hates EMF?
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Unbelievable
 
BruceK said:
well I think I can surmise that OFCOM is off to a great start because nobody seems to have a clue what really is required and the best advice I received is to wear a steel hat.
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If you get boarded by ofcom, just tell them that your radio is broken or that you don't use it.
 
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