DD4YR wrote: "How does it look in Great Britain or France? Or Brazil?"
Yesterday I received a report that 10706 turned 6 - 8 dB stronger in Israel.
11205 wasn't checked.
Posts by PA3FYM
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DD4YR wrote: "Is it possible that the transponder signals then turn out to be significantly weaker than the beacon on 10706?"
While receiving the tests on (iirc) December 23th last year, I saw the transponder noise around 5 - 10 dB above the 'normal' noise with my experimental setup (and
at 739 MHz IF)
Taking the transponder noise as an emperical starting point, I reckon the sensitivity of my receiving chain might be sufficient. So, although the LNB works out of spec I think receiving the (NB) transponder might not be an issue. -
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To remain on topic (RHCP): last weeks G0MJW, M0EYT and I were busy designing, modelling and building prototypes of alternative 2.4 - 10 GHz dual band feeds.
There are several variations of the same theme, but I wanted to have a design without needing lathes or CNC-machines. The result is a (well known) 'cropped' patch, sized and matched with a waveguide in the center.
It took some time to model the correct position of the feedpoint as the waveguide seems to introduce some 'issues', making it not trivial to find the proper position to have (what I call) the 'S11-balloon' circling around Z=1 in the Smith Chart.
Attached a picture of sweeping my interpretation of a prototype, which we name ' 29-16° '. Return Loss (RL) could be improved even more with some tweaking of the patch height at the feedpoint position.
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The dish is (I believe) 64cm, but the effective surface is the width (will measure it later). I also receive the beacons with this setup, around 20 dB SNR (in 2500 Hz BW),
so a little weaker than my other setup.
I tested the setup a while ago while looking at BADR 4 with 11W @2400 MHz and found little degradation, in a sense that the noise floor 'danced' up and down for ca. 2 - 3 dB on my SSB signal.
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DL9DAC : That's exactly the reason why I started this thread with the LEILA-2 questions. Later DB2OS added some posts concerning 'operations' to this thread
so that the initial incentive seems under illuminated.
I don't think the pile-ups itself are an issue, but the way LEILA-2 deals with them.
So, will LEILA-2 do only a 'peak' analysis (inside a 'channel') or will it take the integral of all signals (inside a 'channel') ?
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'Split operation is not desired on the satellite' <--- ???
Says who.... and why not 'desired'? It can't be enforced.It seems to me like the 240 kHz (- two beacons) is already over regulated before the transponders are on ...
Let me give my 2 cts: "Speaking Russian is mandatory" ; -)
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I think what pe1chl tried to explain is that you've to tweak to the minimum, because that's where the 'polarization discrimination notch' is maximal.
In other words: listening to a H-beacon (or program), switch the LNB to V and tweak for minimum signal.
Many broadcast satellites have two (different) programs on the same frequencies/transponder but with different polarities (H and V).
Assuming around 25 - 30 dB polarization discrimination for linear polarizations it's possible to obtain clear (DVB-S) pictures with C/N's of around the same magnitude.
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I don't feel addressed (because I registered earlier) ; -)
Anyway ... I reckon it's useless to speculate concerning " do's and don'ts " before the transponders are operational. Time will learn ...
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I remember having read somewhere that LEILA-2 monitors 'channels' of 2500 Hz BW and have some questions concerning the proposed/designed operation of the jammer (not primarily related to 'channels', but in general).
Imagine the following:
1. I generate a single tone/carrier just below the LEILA-2 threshold (so LEILA-2 will not jam) with 'xW RF'.
2. Next, I generate two tones 1234 Hz apart with equal amplitudes with the same 'xW RF' in such a manner that each tone/carrier is -3 dB cf to 1.
3. Then I Increase the RF output with +3dB (so each tone/carrier is of equal strength cf to one carrier in 1).What will LEILA-2 do and/or is intended/designed to do?
Situation 1. (Hopefully nothing ; -)
Situation 2. ?
Situation 3. ?
Edit: DB2OS Accidentally posted this in the 'Hardware' thread but maybe it should be in the 'bandplan and operating guidelines'? If so, can I move the thread myself or are you willing to?
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I think the 4th and 5th harmonics of 2400 MHz, when present, may be an issue.
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OK, the last sentence in my previous post may be/is confusing.
What I wanted to say is that the skew angle is identical in both cases.
So, if you've e.g. -15 degrees and are behind the dish, thus looking at the satellite, the LNB has to be turned anti-clockwise, no matter if you've a 'normal'/offset dish or a Cassegrain. -
Hi Charlie,
I'm impressed with the signal strength you've of the 10706 beacon. Is that with your EME-dish?
Btw, I'll inform Ron that his LNA outperforms ; -)
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Hi Rene,
Nice to see you here too. Besides that I'm also a fan of 'tweaking' the LNB for max signal, your question is indeed a bit mind boggling.
Assuming that the satellite is East from your longitude:
For a 'normal' (offset) dish, standing in front of it, with your back to the satellite you've to turn clockwise.
For a Cassegrain, standing behind the dish and looking at the satellite you've to turn it anti-clockwise.
In other words it's the same, depending upon what perspective you're looking.
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Ich habe dieselbe Begruendung wie Roland, aber das faellt hier nicht gut.
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After a while you start to recognize the spectral impact of the Es'hail-2 beacons but a rough 'sanity check' could be:
Point the dish to 'satellite X', check if you've BOTH beacons (10706 and 11205), then you're aiming at Es'hail-2. If one of the beacons is missing (or disproportionally weak) you've not the right satellite.
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DB2OS : Thanks for the information. So it will be kept in position more close to 26° than 25.5° E.
(n2yo.com (with a TLE from yesterday) reports between 26.04 - 26.12°, so a little tweaking is needed ; -)
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IW5BT : nice signal, but .. will this be the signal of tomorrow, as you seem to run ahead in time? ; -)