Primarily for general aviation discussion, but other aviation topics are also welcome.
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By WingedSupra
#1830536
I had an email today, from Ofcom, regarding my 'License'. It was completely unclear if it was related to my amatuer radio license or the aircraft license - but on visiting the link it would appear that this could eventually affect both.

The email stated that some new rules are coming which are written about here:

https://www.ofcom.org.uk/manage-your-licence/emf

Did anyone else get this (who doesn't have an amatuer radio license)? Looks like a whole load of extra Carp to potentially deal with - to document and comply with some sort of RF exposure limit to the general public!
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By PeteSpencer
FLYER Club Member  FLYER Club Member
#1830538
Yes I got it as trustee/owner of our aeroplane .

I’ll pour a glass of something red tonight to relieve the boredom and plough through it .
By johnm
FLYER Club Member  FLYER Club Member
#1830539
Pandering to the anti-mast and tin foil hat brigade??
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By FlightDek
FLYER Club Member  FLYER Club Member
#1830551
I've had a look at it and it looks like it is for amateur radio installations. The calculator is to work out the public exclusion zone for your transmitter based on the power and frequency. I have to do these at work for our transmitters in my patch. I can't see how this would be applicable to an aircraft

Dek
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By xtophe
#1830552
Having a quick play with the calculator https://www.ofcom.org.uk/__data/assets/ ... 0.1.2.xlsx

It seems you are allowed to take into account duty cycle. So not count the peak, maximum power but the average power. My duty cycle will be a few % so power negligible like 0.06W for my KRT2 transceiver.
So for VHF you end up with the minimum distance of 0.37m
And for ADS-B of 0.06m

Not sure you can get that close to the antennas without bumping into wings/tailplane. So it will be a non issue for me.
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By Dodo
FLYER Club Member  FLYER Club Member
#1830555
I've not received one. I have both a FRTOL and an aircraft radio licence. Some boat owners I know of have had one.

Perhaps it is because my surname is at the end of the alphabet but so is Pete S's.

I feel left out :-(
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By Marvin
#1830561
I used to do this stuff on radar systems where power levels are a little higher, never had any cause for concern. Did condemn a couple of microwave ovens though.

Just received this from ofcom as well but frankly at the radiated power levels and duty cycle of the average VHF transmitter in GA, base stations and aircraft installation, I cannot see this would be a cause for any concern.
By WingedSupra
#1830564
FlightDek wrote:I've had a look at it and it looks like it is for amateur radio installations. The calculator is to work out the public exclusion zone for your transmitter based on the power and frequency. I have to do these at work for our transmitters in my patch. I can't see how this would be applicable to an aircraft


Totally agree but it does specifically say that aircraft licenses are in scope. So I would imagine we might get some guidance from CAA at some point, and a recommendation to document the fact that the calculation has been done.
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By Rob P
#1830567
Dear god! Is public money really being spent on krap like this right now?

Rob P
By Forfoxake
FLYER Club Member  FLYER Club Member
#1830591
xtophe wrote:Having a quick play with the calculator https://www.ofcom.org.uk/__data/assets/ ... 0.1.2.xlsx

It seems you are allowed to take into account duty cycle. So not count the peak, maximum power but the average power. My duty cycle will be a few % so power negligible like 0.06W for my KRT2 transceiver.
So for VHF you end up with the minimum distance of 0.37m
And for ADS-B of 0.06m

Not sure you can get that close to the antennas without bumping into wings/tailplane. So it will be a non issue for me.


What about transponders?

My mode-C transmitter power is 200W peak minimum @ 1090MHz.

The calculator says 2.73m!

Could this require a big move of the transponder antenna to keep it away from a passenger?

And not sure that I will be able to find a spot in the cockpit for my new SE2 (20W nominal @ 1090MHz) that is 0.86 m away from any passenger.

PS Anyone know how to decide whether to use EIRP (watts) or EIP (watts)?
Last edited by Forfoxake on Wed Mar 03, 2021 8:29 pm, edited 1 time in total.
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