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New EMF requirement for VHF users


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Agreed Ian. It smells of butt-coverage and unenforceable but well intentioned recommendations.

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I guess this is a bit like where we had to test buffet car microwaves for RF leakage. I am also sure myself and neighbours would have been at more risk during my cb radio days throwing 1kw at usb/lsb........ Ahem

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5 hours ago, suzook12 said:

I guess this is a bit like where we had to test buffet car microwaves for RF leakage. I am also sure myself and neighbours would have been at more risk during my cb radio days throwing 1kw at usb/lsb........ Ahem

If you are referring to the late 70's / early 80's ........... I was Busby wiv da yella van 🤣 ........ oh, and an unmarked hillman Avenger estate ..........🙄

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2 hours ago, GPSguru said:

If you are referring to the late 70's / early 80's ........... I was Busby wiv da yella van 🤣 ........ oh, and an unmarked hillman Avenger estate ..........🙄

I had a visit from the DTI? He stood about 6 inches away from a multimode II and a superstar 2000 and missed them bless him, did confiscate my 1kw bremi's tho, but they had blown up at that point.....

 

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17 hours ago, GPSguru said:

I don't think it does affect us for the following reasons,

1) I think that possibly 25W is probably OK, most of the material I have read would indicate that the Radiated RF power would need to be 100W (or more) to even be close to the minimum standards in the guide lines.  Also, you can't really take the antenna gain into consideration as many small boat users have very inefficient antenna systems.

2) The end user cannot be expected to measure the radiated field strength with any accuracy. Many factors come into play here, like the power loss in the coax and the efficiency of the antenna in its mounted position.

3) most end users will be clueless the understanding what radiated field strength is all about and how it is measured. TBF, even some communication professionals will struggle with it

3) The information is international  GUIDELINES, not a mandatory requirement.

4) It seems to me that Ofcomm like to be seen to be doing a good job and disseminating the information they are provided with, however, they need to do this in a way that can be understood by the user base, and not just using copy and paste !

5) If is also about Ofcomm covering their own base, so if there was any legal action by a member of the public against a licensed radio user for radiation damage then Ofomm can say they provided the information. I think this scenario is more remote than any of us getting 6 numbers on Saturday !

 

 

 

Agree with above. It’s not a legislative change. I also understand that changes apply to CB radio and other amateur telecom enthusiasts so it’s quite generic...

Its not enforceable in current production as standards typically apply when you place equipment on the market. Once sold any legislation change cannot be retrospective.

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Using their calculator.

25w at 156kHz, the safe distance is 1.6 metres away from members of the general public. So no problem.

Edited by MegaByte
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5 minutes ago, MegaByte said:

Using their calculator.

25w at 156kHz, the safe distance is 1.6 metres away from members of the general public. So no problem.

And to take this one step further, any friends you have on board are classed as "general public" so they must stay 1.6m away from the aerial during transmissions... 😉

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35 minutes ago, Andy135 said:

And to take this one step further, any friends you have on board are classed as "general public" so they must stay 1.6m away from the aerial during transmissions... 😉

So if we dress the aerial up as someone looking ill and tell them it has covid.... They could socially distance?

Some boats would struggle to get 1.6M away

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44 minutes ago, MegaByte said:

I only take friends, not members of the general public.

Yes, me too. But the guidelines classify the "general public" as anyone who is not the spectrum user (VHF radio owner) or anyone employed by them (either directly or a subcontractor).

So our friends would fall into the category of "general public" for the purposes of the guidelines. 🤦‍♂️

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This could discourage some people from having a VHF on their boat and to rely on a mobile phone instead, resulting in a reduction in safety.

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This is pretty much what was discussed in part of the coxswain 1 course I did where emf from radio's and radar were described as dangerous on vessels, which of course everyone disagreed with when I mentioned it on another very large UK based site!!!!

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10 minutes ago, Maverick said:

I doubt it Brian, most of us are to stupid to worry about a lot of words

Whilst I wholeheartedly agree that most of of seasoned boat owners are too stupid to worry... 🤣... I believe that this could be a barrier for the newbie boater to invest in a VHF if they have even more hoops to jump through. Let's face it, doing the VHF course is a faff, even if it is in fact very useful. A newbie owner may see the Ofcom guidelines as the straw that breaks the camel's back, without having the contextual knowledge that we all do that the guidelines are just guidelines, and they are unenforceable in practical terms.

IMO Ofcom should be making it easier for boaters to stay safe, not harder.

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8 minutes ago, JDP said:

This is pretty much what was discussed in part of the coxswain 1 course I did where emf from radio's and radar were described as dangerous on vessels, which of course everyone disagreed with when I mentioned it on another very large UK based site!!!!

Bad luck Jon. You can lead a horse to water and all that...

Makes you wonder what they think makes their microwave ovens work. 🤦‍♂️

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I've just tried the calculator,

VHF radio Separation Distance = 1.6m

Radar Separation Distance = 6.69m (a bit tricky on my 5m boat)

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1 hour ago, MegaByte said:

I've just tried the calculator,

VHF radio Separation Distance = 1.6m

Radar Separation Distance = 6.69m (a bit tricky on my 5m boat)

In simple terms ..... yes ...... but

Did you take into account the loss in the coax (attenuation) and also the gain of the antenna. A standard 1.4 glass fibre whip is 3db gain, so assuming a perfect installation then the ERP ( Effective Radiated Power) will be 50w.

However, you would also need to plot the field (using a calibrated field strength meter) to enable you to plot a polar diagram for the antenna.

On the RIB I have  unity gain quarter wave whip mounted on the A frame which is fed by approx 8m of RG58U coax, so the cable loss will be about 1.9db, therefore my ERP at the antenna is significantly less than 25w ( cant be arsed to work it out exactly, but it will be around 15w (ish).

Can the end user be expected to know all this stuff, I spent 40 years in the industry including a number of years in enforcement with the Ofcomm predecessor.

 

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Simple answer = No and I'm not going to.

They'll never be able to enforce it for amatuer boaters, it's aimed at Mobile Phone networks.

 

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I got AIS, VHF (may add another VHF as well) and Radar. 
 

They can try come take readings but if I see them coming they’ll need a wet suit 🤣🤣

You are more in danger of my chum bucket or my cooked breakfasts than getting cooked by EMF on my boat 

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I tried to read it a few times but just my eyes just glazed over both times

I'll wait and let Jon C explain it in simple terms for me

Him being the forum tech geek an all

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7 minutes ago, jonnyswamp said:

I tried to read it a few times but just my eyes just glazed over both times

I'll wait and let Jon C explain it in simple terms for me

Him being the forum tech geek an all

🤣🤣🤣🤣🤣

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10 hours ago, jonnyswamp said:

I tried to read it a few times but just my eyes just glazed over both times

I'll wait and let Jon C explain it in simple terms for me

Him being the forum tech geek an all

Swampy my dear thing , I could spend hours talking about the effects of ERF on here as I have done on some of the EFR forums that I’m a moderator on. One of those discussions got fairly heated recently and culminated in an organised knife fight in a 20 yard skip on an industrial estate in slough. 
The thing is it would go so far over the other members on here’s head it just isn’t worth talking about. 

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39 minutes ago, JonC said:

Swampy my dear thing , I could spend hours talking about the effects of ERF on here as I have done on some of the EFR forums that I’m a moderator on. One of those discussions got fairly heated recently and culminated in an organised knife fight in a 20 yard skip on an industrial estate in slough. 
The thing is it would go so far over the other members on here’s head it just isn’t worth talking about. 

Try it. It’ll be interesting to see just how much you could copy and paste off of google. 

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8 minutes ago, Saintly Fish said:

Try it. It’ll be interesting to see just how much you could copy and paste off of google. 

It really would be a waste of my time and more importantly resources. We need to consider the rain forests and the destruction to the planet caused by unnecessary posts. 

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