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Call Sign : 26-CT-3228 / M7VIC Posts : 5779 Times Thanked : 352 Join date : 2019-11-10 QTH or Location : Bedford Equipment Used : Various
Subject: Re: RSGB EMF compliance Sat Dec 11, 2021 8:58 pm
Ah, but even FT8 for example is pretty much full bore for a shade under 13 seconds on transmit. No phone or CW comes anywhere near that for transmission duration.
We can argue finer points but also be grateful that SSB isn't asked for compliance on the peak power!
G0RQQ Contributor
Call Sign : 26CT866 Posts : 54 Times Thanked : 1 Join date : 2019-08-23 QTH or Location : Lincoln Equipment Used : CRT2000 on CB, FT-920 on amateur bands; end-fed wire 20m long
Subject: Re: RSGB EMF compliance Sat Dec 11, 2021 9:06 pm
What has happened is the mode duty rate has gone down from 72% to 42% but the transmit percentage has gone from user-selectable to 100% fixed.
Anyway, it’s not due to be implemented until May 2022 by which time the calculator will probably have changed again….
Victor likes this post
Victor CT Directors
Call Sign : 26-CT-3228 / M7VIC Posts : 5779 Times Thanked : 352 Join date : 2019-11-10 QTH or Location : Bedford Equipment Used : Various
Subject: Re: RSGB EMF compliance Sat Dec 11, 2021 9:28 pm
Bang on there Keith and as you say there's bound to be some more changes to the calculators before they're through.
Victor CT Directors
Call Sign : 26-CT-3228 / M7VIC Posts : 5779 Times Thanked : 352 Join date : 2019-11-10 QTH or Location : Bedford Equipment Used : Various
Subject: Re: RSGB EMF compliance Sun Dec 12, 2021 8:47 am
Had a bit more of a ponder on this 'duty cycle' and the discussions going around elsewhere regards this...
Is it misunderstanding or worming our way out?
If I key up CW continuously for 1 hour every day am I operating at 1/24th or a shade over 4% ? (Someone's bound to mention I'll blow me finals. )
Of course not, so I have to do my compliance on my actual transmission not the gaps inbetween.
If I jump off a 100 foot building the first 99 feet are perfectly safe.....it's the last foot you've got to worry about!
G0RQQ Contributor
Call Sign : 26CT866 Posts : 54 Times Thanked : 1 Join date : 2019-08-23 QTH or Location : Lincoln Equipment Used : CRT2000 on CB, FT-920 on amateur bands; end-fed wire 20m long
Subject: Re: RSGB EMF compliance Sun Dec 12, 2021 9:13 am
As they say, it’s not the fall that kills you - it’s the sudden stop at the end!
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Alan Pilot Major contributor
Call Sign : 163-CT-220...MW7TTA Posts : 2510 Times Thanked : 69 Join date : 2019-11-19 QTH or Location : Anglesey North Wales Equipment Used : Yaesu FT-991A,,Yaesu FTDX-10,,Icom ic-7300,,Anytone AT-D878UV PLUS",,LINCOLN II+. Age : 150
Subject: Re: RSGB EMF compliance Sun Dec 12, 2021 9:16 am
Morning Victor. I gave up researching the ft4/8 as so many contradictions on many posts. Just make your own mind up and stick to that lol 50% or 100%. But how can it be 100% when it's 50/50 lol. Chicken or egg.
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Victor CT Directors
Call Sign : 26-CT-3228 / M7VIC Posts : 5779 Times Thanked : 352 Join date : 2019-11-10 QTH or Location : Bedford Equipment Used : Various
Subject: Re: RSGB EMF compliance Sun Dec 12, 2021 9:19 am
Ha! Ha! Love it Keith.
Victor CT Directors
Call Sign : 26-CT-3228 / M7VIC Posts : 5779 Times Thanked : 352 Join date : 2019-11-10 QTH or Location : Bedford Equipment Used : Various
Subject: Re: RSGB EMF compliance Sun Dec 12, 2021 9:32 am
Morning Alan,
There's loads going on to cloud the issues but in all reality you can either be transmitting or not. (Felt like flipping Yoda then! )
The EMC compliance concerns our actual transmissions not the gaps between. It all gets complicated with phone modes such as Sideband or even AM and I think they've done a splendid job at allowing a percentile rather than a peak measurement. But FT8 still is a 12.6 second full on transmission and you only have to look at our power meters to see that.
If we argued that our Foundation 10W limit could be increased somehow due to the 'duty cycle' of transmission there'd soon be complaints!!!
G0RQQ and Alan Pilot like this post
G0RQQ Contributor
Call Sign : 26CT866 Posts : 54 Times Thanked : 1 Join date : 2019-08-23 QTH or Location : Lincoln Equipment Used : CRT2000 on CB, FT-920 on amateur bands; end-fed wire 20m long
Subject: Re: RSGB EMF compliance Sun Dec 12, 2021 11:30 am
I’ll have to recheck some of the numbers for my FT4/8 transmissions as I was borderline compliant on a couple of bands. Unfortunately because of where I live I can’t reorientate my antenna so a slight power reduction might be needed.
Victor likes this post
G0RQQ Contributor
Call Sign : 26CT866 Posts : 54 Times Thanked : 1 Join date : 2019-08-23 QTH or Location : Lincoln Equipment Used : CRT2000 on CB, FT-920 on amateur bands; end-fed wire 20m long
As I mentioned before, I cannot change my antenna as it has to be a “stealth” installation. So what I did was work backwards from ICNIRP compliance to what would be the maximum power I can use.
I was pleasantly surprised to find that I can run enough RF from my station to meet my objectives. OK, it’s not a kilowatt or even 100 watts but it’s enough enable me to have respectable global contacts.
I’m quite happy to accept the limitations secure in the knowledge that my station is operating safely.
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Victor CT Directors
Call Sign : 26-CT-3228 / M7VIC Posts : 5779 Times Thanked : 352 Join date : 2019-11-10 QTH or Location : Bedford Equipment Used : Various
Really impressed that you have found a way to abide by not only regulations we found imposed on us but also taken on the personal responsibilities associated. More pleased that you have discovered you can still operate your station effectively even under what many coined as 'restrictive' terms.
It's all to easy to use crank up the watts with complete disregard for others and often quite pointless if you can transmit further than you can ever receive. Even a 'pileup' can be effectively worked with better operating methods rather than bullying your way in with power usage.
Got to say, I'm happy for you and tip my hat in recognition of your true Radio Amateur spirit.
Thanks for posting your findings, it's sure to help others.
All the very best, Victor
(Had to give you a 'Thanks' vote too Keith, most impressed.)
G0RQQ Contributor
Call Sign : 26CT866 Posts : 54 Times Thanked : 1 Join date : 2019-08-23 QTH or Location : Lincoln Equipment Used : CRT2000 on CB, FT-920 on amateur bands; end-fed wire 20m long
I found that on most HF bands I can use powers in the region of 25 watts and still be ICNIRP compliant. At 25 watts I am 6dB or 1 S-point down on 100 watts. So what if I’m S8 instead of S9? An S8 signal is still enough for a good solid QSO!
Wireless Major contributor
Posts : 350 Times Thanked : 12 Join date : 2021-11-19 QTH or Location : Shrewsbury Equipment Used : kit
Well, looks like my plan to use 1 Watt FM on 70cms, 5 Watts SSB on 2m, and 1 Watt SSB on 4m into vertical Dipoles at ~5m all meets compliance.
Even the 10 Watts on 6m/2m/70cms on SSB into the V-2000 at ~7m seems to be cool.
10 Watts on 40m SSB into the Horizontal Dipole Whips at ~3.7m is good.
10 Watts HF into the random half wave ~96 metres Horizontal Wire at ~6m seems ok too.
But 11m 4W FM into the 5/8ths Silver Rod at ~2m seems to not be compliant?
What's that all about?
G0RQQ Contributor
Call Sign : 26CT866 Posts : 54 Times Thanked : 1 Join date : 2019-08-23 QTH or Location : Lincoln Equipment Used : CRT2000 on CB, FT-920 on amateur bands; end-fed wire 20m long
That’s similar to what I discovered when doing the calculations for 10m FM with my end-fed wire. I just elected to do the calculations based on 2 minutes talk-time in every 6 minutes on the basis that 10m FM contacts tend to be brief in nature - then everything fit!
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Ivy Mike Major contributor
Call Sign : 26CT4113/G1HWY Posts : 454 Times Thanked : 12 Join date : 2021-05-16 QTH or Location : IO90uv Equipment Used : ICOM radios/antenna farm Age : 68
I'm good 100watts max to the cobweb at 7metres. No one can get near it in my garden or the three gardens that join mine.
The Hustler will just be ok on 20/17/15 and 10 although I don't use it for those bands.
The Create log periodic for all bands 50megs to 23cms is ok, it's way above our roof the nearest building is next doors dormer with a bit to spare. I'm safe with 100watts 2m, 50watts on 6 and 4m, 75watts on 70cms and 10watts on 23cms.