[Moon-Net] 23cM's Future

Nando Pellegrini i1ndp.nando at gmail.com
Wed Sep 18 07:21:53 CEST 2019


Bob,
I can put the dish in any direction but the results are always the same, 
it looks like a lot of scattering or reflections.
I forgot to say that the recording was taken with a hold function so 
signal are from radar and a very short duration so the effect on EME 
activity are low but some other use (like radio astronomy) is totally 
forbidden.
nando,i1ndp

On 9/17/2019 19:05, Bob Atkins wrote:
> Nando
>
> Was this with an EME dish pointed towards the moon? There's certainly 
> a lot of use of this part of the spectrum in this recording, but is it 
> interfering with EME operation? The important question for EME 
> operators is whether there is an increase in the noise floor in the 
> 1296.000 - 1296.150 region when the antenna is pointing up (and not at 
> a Galileo satellite!).
>
> So far here, I don't see any general noise floor increase on 1296 
> (though 432 is another matter). In some directions and at some times 
> do see what appear to be radar pulses, but they are short duration and 
> seem to have little or no effect on EME signal decoding. 23cm has 
> always been a secondary allocation. There's some interesting info at 
> https://science.nrao.edu/facilities/vla/docs/manuals/obsguide/rfi which 
> shows RFI at the VLA radio telescope.
>
> 73
> Bob, KA1GT
> ------------------------------------------------------------------------
> *From:* Moon-net <moon-net-bounces at mailman.pe1itr.com> on behalf of 
> Nando Pellegrini via Moon-net <moon-net at mailman.pe1itr.com>
> *Sent:* Tuesday, September 17, 2019 9:26 AM
> *To:* moon-net at mailman.pe1itr.com <moon-net at mailman.pe1itr.com>
> *Subject:* Re: [Moon-Net] 23cM's Future
> I hope you are luckier than me but i don't need to wait for WRC 2023  to
> understand what's going to happen on 23cm.
> If you look at this:
> https://www.dropbox.com/sh/kxjqe0ro9821fw8/AAB5q2D0-FNduAx7_hFJlf94a?dl=0
> ,and regardless to the quality of the camera operator, it is a 1 minute
> real time recording centered at 1300Mhz with 56 Mhz bandwidth window.
> I do not see any room for secondary users.
> Galileo has nothing to do with it.
> 73,nando
>
> On 9/17/2019 14:03, JOHN REGNAULT via Moon-net wrote:
> > Bob KA1GT is spot on in his analysis:
> >
> > The DEFINITIVE, non-rumour version is:
> > "23cm, there has been concern about a few cases of interference from 
> amateur signals to the Galileo navigation system, specific to its E6 
> sub-band at 1260-1300MHz. It is IARU’s firm view, and stated in the 
> paper it has submitted, that this should be properly studied within 
> CEPT, rather than proposed as an agenda item for WRC-23."
> > Please see: 
> http://rsgb.org/main/files/2019/08/CPG19-116_IARU-AI-10_Amateur-GNSS.pdf
> >
> > The outcome of the CEPT meeting includes the following statement: " 
> The draft Resolution that would guide such studies excludes the 
> removal of the existing amateur Secondary allocations."
> > 
> https://www.iaru-r1.org/index.php/174-news/latest-news/1886-cept-cpg-finalises-its-positions-for-wrc-19
> >
> > The 1296MHz band is not completely  out of the woods, it is unlikely 
> never to be without significant threat as are most other amateur 
> VHF-microwave bands! These are very long term 2023+++ issues which 
> should not impact anybody's plans to exploit a band.
> >
> > So to a number of posters who have relayed wrong information, unless 
> you know the true situation, please do not post rumour or your own 
> interpretation of second hand information which is probably wrong!
> >
> > 73
> > John G4SWX
> >
> > Date: Mon, 16 Sep 2019 23:47:40 +0000
> >
> >
> > From: Bob Atkins <ka1gt at hotmail.com>
> >
> >
> > To: "moon-net at mailman.pe1itr.com" <moon-net at mailman.pe1itr.com>,
> >
> >
> >      "parinc1 at frontier.com" <parinc1 at frontier.com>
> >
> >
> > Subject: Re: [Moon-Net] 23cM's Future
> >
> >
> > The only reason not to do to a bigger dish (other than the obvious 
> cost and complexity) would be fear of regulatory interference with 
> 1296, not RF interference from Galileo satellites using E6 mode which 
> in principle has up to a 40MHz bandwidth extending up to 1300 MHz). 
> Even if it did raise the noise floor at 1296 (unlikely), the effect 
> would be small and not last long as the offending satellite and the 
> moon moved around their orbits.
> >
> > No band is 100% safe from regulatory interference, especially not in 
> the VHF/UHF/Microwave region. It seems pretty unlikely that the USA 
> will lose access to 1296 any time in the near future. Slightly more of 
> a issue in Europe - which could be a problem for the US since most of 
> the activity on 1296 comes out of europe! I think the current proposal 
> is to discuss the issue in 2023 (WARC23), so nothing should happen 
> before then.
> >
> > If I was thinking of up a bigger dish for 1296 (especially one 
> significantly bigger than 14ft), I think Galileo would be pretty low 
> on my list of reasons not to do it!
> >
> >
> > 73
> >
> >
> > Bob, KA1GT
> >
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