IARU 23cms update

Discussion and announcements about ATV related spectrum
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g8gtz
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IARU 23cms update

Post by g8gtz » Tue Aug 02, 2022 8:46 am

2 more documents from the IARU team led by Barry G4SJH have been published on the IARU region 1 site.

The first one is the IARU R1 response to the EU commission requesting for input to help determine the EU position at WRC 23. Note this also includes a briefing on1,300 to 1,325 MHz, 3.4 and 10GHz which are also "being looked at", as well as 23cms below 1,300MHz......

There was never a more important time for ATVers and Microwavers to support the work of the IARU - you can do this by joining and supporting your national society.

In the UK the RSGB may not always be the most popular organisation but they do good work behind the scenes and fund / support Barry and others to prepare for and attend these meetings to fight our corner. Certainly worth the £4.33 a month standing order and less than a pint of beer!

Barry says:
In a collaboration between the IARU-R1 Spectrum and Regulatory Liaison Committee (SRLC) and the Political Relations Committee (PRC) an IARU Region 1 response has been provided to the European Union consultation on the WRC23 agenda items.

All the agenda items of interest to the IARU are covered with particular attention paid to the AI9.1b issue on the GALILEO / 23cm band amateur service coexistence. This is an important messaging activity and the IARU response again underlines the IARU view that with only two cases of interference recorded globally, the potential for interference is being over-stated and that any regulatory solutions should be proportionate, realistic and appropriate and should not hinder the future development of amateur services. The IARU would be pleased if member societies could share these same views with their national regulators.

The full IARU R1 response can be found at
https://www.iaru-r1.org/wp-content/uplo ... mitted.pdf
Secondly the CEPT project team SE40 that is carrying out the CEPT studies on the RNSS/23cm band topic met during the week 25 – 28th July 2022. The IARU provided a contribution and participated in the meeting supported by USKA.

Good progress was made but further work continues to be required to finalise the conclusions from the studies. The IARU continues to be concerned about the lack of consideration being given to the low probability of interference and more work is needed on this aspect. A summary report can be found at
https://www.iaru-r1.org/wp-content/uplo ... E40_77.pdf

Update - Link to Summary Report now corrected.

g8gtz
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Re: IARU 23cms update

Post by g8gtz » Thu Nov 23, 2023 10:04 am

WRC23 has begun in Dubai and the IARU has published an update on the 23cms situation.

https://www.iaru.org/wp-content/uploads ... v-2023.pdf

The technical details of the proposal going to WRC for agreement are here:

https://www.iaru.org/wp-content/uploads ... 2MSW-E.pdf

73
Noel - G8GTZ

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Re: IARU 23cms update

Post by G8GKQ » Thu Nov 23, 2023 11:03 am

Barry has just published a more readable summary here:

https://www.iaru-r1.org/wp-content/uplo ... maryr1.pdf

Dave, G8GKQ

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i2NDT
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Re: IARU 23cms update

Post by i2NDT » Thu Nov 23, 2023 12:01 pm

what I'm not sure to understand is:

For Broadband:
1 255.76-1 256.52 MHz: e.i.r.p. = 24 dBW/150kHz*
1 256.52-1 258 MHz: e.i.r.p. = 21 dBW/150 kHz*

and

*24 dBW/150 kHz = 50W/2MHz
*21 dBW/150 kHz = 25W/2MHz

in the last slide...

best 73
de
i2NDT Claudio
i2NDT Claudio
Dalmine, Italia

g4eml
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Re: IARU 23cms update

Post by g4eml » Thu Nov 23, 2023 5:15 pm

I was confused by that 24 dBW/150 kHz = 50W/2 MHz as well.

I think it refers to the allowable power into the 18dB gain antenna assumed in the document. Someone please correct me if I am wrong.

150 kHz to 2 MHz is 13.333 times or 11.25 dB.
Allowable power in 2 MHz would be 24 + 11.25 = 35.25 dBW
Antenna gain is assumed to be 18 dB so power to antenna would be 35.25 - 18 = 17.25 dBW
17.25 dBW = 53 Watts

Except of course the 24dBW/150 kHz is only 760 kHz wide so you couldn't actually run a 2 MHz wide signal at that power.
So the limit for a 2 MHz wide signal would be 21 dBW/150 kHz or 25 W into an 18dB antenna.


Colin G4EML

g8gtz
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Re: IARU 23cms update

Post by g8gtz » Sun Nov 26, 2023 5:43 pm

For those who prefer pictures, I have merged 2 drawings from the IARU presentation to show the actual power levels allowed in the PROPOSED wide band segment.

Note this is the only place ATV will exist on 23cms worldwide if this proposal is accepted - the UK will still retain 25MHz above 1300MHz for now....
ITU3.jpg
ITU3.jpg (393.38 KiB) Viewed 16498 times

g6jyb
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Re: IARU 23cms update

Post by g6jyb » Sun Nov 26, 2023 6:52 pm

Take care - the curves you are looking at are 'guidance', and at present CEPT is facing some opposition to make it mandatory globally.

Read on here (inc another issue that may affect 29 and 51 MHz)

https://rsgb.org/main/blog/front-page-n ... -and-more/
https://rsgb.org/main/blog/front-page-n ... 1-summary/

and more as we go at https://rsgb.org/main/blog/category/new ... us/wrc-23/

But you can be pretty certain about the end of 23cm FMATV though (inc in 1300-1350).

73

Murray G6JYB - at WRC too

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G3GJA
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Re: IARU 23cms update

Post by G3GJA » Sun Nov 26, 2023 11:42 pm

The wideband segment is of no use is you are within 50km of the Claxby radar in Lincolnshire on 1254.5MHz

Clive

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