OFCOM Change Of Licence Requirement

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C Rule
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OFCOM Change Of Licence Requirement

Post by C Rule » Wed Mar 03, 2021 5:29 pm

.I recieved the following from OFCOM today as I suspect many have.
The calcutation for a comms radio is easy but my transponder is rated at 250W out peak
Does anyone know what the nominal duty cycle is for a transponder?
Colin
Dear Licence Holder,

We are writing to make you aware of some important changes that we are proposing to make to your Wireless Telegraphy Act licence(s) issued by Ofcom.

In February and October last year, we issued two public consultations on our proposal to formally require licensees to comply with the internationally agreed levels in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) Guidelines for the protection of the general public from electromagnetic fields (EMF). We refer to these levels as the ICNIRP general public limits. In October, we also issued a Statement setting out our decision to formally require licensees to comply with the ICNIRP general public limits and we recently published an update on how we propose to implement that decision.  

We are now writing to you to inform you of our proposal to vary the terms and conditions of your licence(s) to require you to comply with the ICNIRP general public limits. In accordance with the Wireless Telegraphy Act and your licence(s), we are giving you notice of our proposal by publishing a General Notice on our website. 

We’ve put all the relevant information about our proposal including the General Notice on a dedicated EMF webpage ofcom.org.uk/emf. Here you will find details of the licence variation process alongside the background to the changes and lots of FAQs to help you understand what our proposal means for you. 

If, after reading the above information, you wish to make a representation to Ofcom in relation to our proposal to vary your licence(s), you have up until the 18 April 2021 to do so. However, if you do not wish to make a representation you do not need to take any action at this time. More information on the representation process can be found by visiting the Ofcom EMF webpage.

We will consider all representations before coming to a final decision on the variation of your licence(s). We will publish our final decision on the EMF page of our website by 18 May 2021. We will explain whether we have decided to vary your licence(s) to include the EMF condition. If your licence(s) has been varied we will send you an update of it or information on where a new version can be obtained from. 

In future we intend to make greater use of General Notices published on our website and may not individually contact you to inform you that we have published one. We would therefore urge all licensees to regularly check the Ofcom website or subscribe to email spectrum updates by going to the following page on our website ofcom.org.uk/about-ofcom/latest/email-updates.

If you have any questions about this change and what it means for you, further information can be found on the dedicated EMF webpage using the address provided above.

Yours faithfully, 

Ofcom
Colin Rule
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Mark A
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Re: OFCOM Change Of Licence Requirement

Post by Mark A » Wed Mar 03, 2021 9:48 pm

I had the same email.

Nothing to worry about as far as I can see.

My transponder is also about 200W, but only draws 1/3 A, so 4W of power consumption.
That's for transmitter, receiver and display; so the radiated EMF must be less than 4W average.
If there were any risk of microwaving your bodily organs, I think we would know about it!
Mark Albery
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Ian Melville
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Re: OFCOM Change Of Licence Requirement

Post by Ian Melville » Wed Mar 03, 2021 11:01 pm

Not quite as simple as that Mark. The documentation is going to be a faff

I also don't understand your transponder output power maths. If it is listed as 200W, then that will be the output power, though not all will get to the antenna. Are you trying to use the input power to compensate for the unknown duty cycle?

I hope the LAA knew about this? It is the first I have seen of it and it is supposed to have been out to public consultation! Waiting to see if there is any guidance.
Ian Melville
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markdesmond
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Re: OFCOM Change Of Licence Requirement

Post by markdesmond » Thu Mar 04, 2021 12:53 am

Every aircraft radio licence holder I know has had this email. The power output of most transceivers is below the ICNIRP EMF threshold, so of no concern. However, if you have a transponder, will it be legal to fly with with friends and family who are not included in the exemption? Owners and operators are exempt. See below.

Did anyone know about the consultation? I do not know of anyone who did. It seems to me that once again OfCom are meddling in the aviation area, just as they did when it came to selling frequency licences at £3k a pop to minor airfields.
Do Equipment installation guidelines and the manufacturers of our avionics not already design them to offer satisfactory protection to crew and passengers, or anyone that we might taxy passed or over fly?
Can the association engineering team provide guidance please?

The EMF condition requires spectrum users to ensure members of the general public (as defined in the EMF condition) are not exposed to levels of EMF above the ICNIRP general public limits.
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.

4.2 This means that the EMF condition does not require spectrum users to comply with the ICNIRP general public limits if they have determined that only the licensee, owner, operator or installer of radio equipment may be exposed to EMF in breach of the ICNIRP general public limits. For example, an amateur radio licensee does not need to comply with the EMF condition in respect of their own exposure to EMF. The EMF condition also does not require amateur licensees to protect each other from EMF when they are visiting each other or working together.

Ofcom have clearly not heard of the Red Tape challenge :(
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Ian Melville
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Re: OFCOM Change Of Licence Requirement

Post by Ian Melville » Thu Mar 04, 2021 7:56 am

Ofcom have clearly not heard of the Red Tape challenge :(
They have, they just thought it was a challenge to create more :-(

Mark, you did read this bit
This Guidance applies to:
a) Licensees that are subject to an EMF condition in their spectrum licence(s)1; and
Ofcom have told us that they intend to change the wording of our licence. IF that is to include and EMF condition, then we will have to comply despite being well under the 10w EIRP?
Ian Melville
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C Rule
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Re: OFCOM Change Of Licence Requirement

Post by C Rule » Thu Mar 04, 2021 8:18 am

I think this came as a shock to all in aviation I have asked the question of various maintainence organisations involved in the certified world and they did not know it was coming. The question was raised what happens with wx radar where the peak power is considerably greater than 200w?
Colin Rule
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markdesmond
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Re: OFCOM Change Of Licence Requirement

Post by markdesmond » Thu Mar 04, 2021 8:35 am

I think I have just about lost the will to live Ian. We are being pecked to death by mindless regulation, I think I am about to be required to apply for at least my third valid for life licence and rating to continue to tow gliders. My Fournier RF-3 is sort of orphaned by EASA because Rene refuses to pay them the fee as the type design authority, so there is now a question mark about continued permits to fly. The strip I fly from is encompassed by this summers massive TDA to allow the RAF to fly SkyGardian drones this summer and Protector in 2023. Mogas is going to be E10 from September, so non compliant with aviation law/use for very good reason. The duty on both Avgas 100LL and UL91 looks set to increase. I am a member of 3 permit aircraft syndicates all insured and in permit to fly but like the rest of us, have not been permitted to fly for months. I walk or cycle passed the strip most days and think the argument for flying solo is now very valid. My certificate of experience medical and permits to fly are all ticking down. Perhaps it is time to take up fishing, which I think it has been permitted throughout. :(
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Ian Melville
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Re: OFCOM Change Of Licence Requirement

Post by Ian Melville » Thu Mar 04, 2021 9:14 am

I thinks that just about sums it up Mark :cry:
Ian Melville
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C Rule
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Location: South of 70 north

Re: OFCOM Change Of Licence Requirement

Post by C Rule » Thu Mar 04, 2021 11:50 am

The offices of goverment need to get out of the European mindset of continual intrusive regulation.
I had hoped this might happen after Brexit
:cry:
Colin Rule
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C Rule
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Re: OFCOM Change Of Licence Requirement

Post by C Rule » Thu Mar 04, 2021 5:05 pm

Just received the LAA response to OFCOM's email.
Very impressive response in a short time frame.
Thanks
Colin Rule
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pdyer
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Re: OFCOM Change Of Licence Requirement

Post by pdyer » Sat Apr 03, 2021 9:09 am

Hi, from Trig website, in case you have missed it.
Kind regards,
Peter Dyer

XPDR
Are there any adverse RF radiation effects from using a transponder?
Although Trig transponders can output a nominal power up to 260 Watts, the transmission is pulsed and has a duty cycle of about 0.55%. This means that the effective radiation power is about 2 to 3 watts.
With an antenna more than 50cm away, plus the effects of the aircraft skin, ground planes, obstacles and basically not a direct path, the actual RF radiation reaching the cockpit is very low and considered no more of a risk to health than mobile phones.


Radio
For our VHF radios, although you probably don’t transmit all the time, it is certainly possible to exceed the 10 W limit. That is even true for our 6 W rated transmitters – because the ICNIRP limit takes account of the antenna gain and directionality, and the field strength can be higher than the nominal power. You therefore need to consider the safe distance for these radios between the transmitting antenna and any member of the public. The actual safe distance will depend on the transmitting antenna configuration, but we have calculated the distances for conventional aircraft antennas.
Allowing for typical antenna cable losses, for our 16 W radios, such as TY97 and TY92, the safe distance is about 1.8 metres or 6 feet. For our 10 W radios, such as TY96 or TY96A, the safe distance is about 1.51 metres, or 5 feet. Finally, for our 6 W radios the distance is about 1.17 metres, or 3 feet 10 inches.

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