Ok, I now know what KML is! Thank you for teaching me something new today!
Sorry.... it is Keyhole Markup Language, similar to XML and used for doing clever stuff in google earth etc. I use it in a simple way to overlay images or tracks on maps. This is rather useful if you have been doing mobile coverage measurements or want to overlay a prediction on top of a map.
Frankly, at the moment, I would install an OLED. The current software does not really utilise it yet. It is giving the same information you see in minitiouner so unless you really need to see this twice there isn't much gain. It's something for future extension. The much large colour OLED will be the one to have if you insist on early adoption.
Mike
I think there is a wide problem with emails not being delivered or flagged as spam, especially when containing words like password or sent from suspicious email domains like btinternet. Maybe another way of registering would be to allocate a default password which then has to be changed?
Mike
I don't speak much french nor any German (sorry). I used Google translate and sent an email to REF in English and French asking to buy one. You don't need to be a member. Very efficient one communication was successful.
You can plot stuff in Google earth using kml - not too hard to generate.
"The end-user will be able to connect to the Starlink satellites using a special terminal the size of a medium pizza (0.48 meters in diameter) that looks like a thin, flat, round disc on a stick.
Wer hält 48cm für eine mittelgroße Pizza?
This is interesting. Evariste says the beacon is encoded in real time. Given it does not change I had always assumed that the audio and video were pre- encoded with the highest quality settings, multi-pass, in non-real time, latency not a problem, on some professional equipment and then saved for transmission. That's why the content never changes I thought. If it's re-encoded each pass then it could have things added to it, like a clock, TLEs or alerts.
Mike
Very interesting. Keep up the analysis - this is good research. If everything works there is little more of interest to do, it is when there are problems it gets interesting. That's the one of the benefits of amateur radio, we push boundaries. We fail, we fix, we develop.
One point we might consider is that this did not happen earlier. Now was that because there has been a change in the TS or is it because Microsoft updated their codec? Perhaps analysis of a recorded TS from the beacon prior to the change would be instructive here. I will look to see if I have anything, I did save the beacon right at the start but as it's such a high rate, I don't think I have a more recent recording. Maybe others have. If we can find such a recording a comparison of the differences might throw up clues as to the cause.
Mike
That's very encouraging. Mine is still in shipping.
Mike
Yes, that simulation was done the next day. That's when I got into the limits of the student version and much less confident about the results. Thinking about it now, instead of discs if loops were used as directors it might work better. In any case a lot of extra mechanical work to gain a dB.
Peter,
Perhaps both measurements are correct but the beacon is sometimes working properly and sometimes not? We have seen this before when a reboot fixed it.
Mike
Display MoreIf you have some experience with Matlab/Octave, you might give openEMS a try.
https://openems.de/index.php/Tutorials
https://openems.de/index.php/T…Simple_Patch_Antenna.html
https://github.com/thliebig/openEMS
This is an open source 3D-FDTD simulator, available for 64Bit Windows and Linux.
The size and complexity of the models is only limited by the computer's RAM and the computing time. Compared to e.g. HFSS I could not find any significant differences in the results.
By the way, a Python interface is in preparation.
73+55 Roland
I tried it - but the learning curve is so hard. Meanwhile, I had a patch simulated and working in CST within 24 hours.
One from DB6NT probably - or other similar makers. Problem is it costs 300 Euro and you need a waveguide transition. That's not unreasonable given what it costs to make but it's also why Octagon PLL LNBs are such fantastic value.
https://shop.kuhne-electronic.…U+LNC+10+QO100/?card=1875
If you add one of the low noise amplifiers it's even better of course. These are really for EME.
Mike
It was me who wrote to aim for exactly 3.0 mm. It's really critical, sorry. Good idea to adjust your spacers to get the correct outcome when assembled.
Mike
From Evariste, F5OEO. The original site is no longer up and the version on Vivadatv is out of date. The best solution is to contact him and follow the guidance in the help file.
Mike
From the help file:
Support
If you have any questions regarding this custom firmware or are experiencing any problems following the user guides, or experiments feel free to ask a question. Questions can be asked on our vivadatv forum.
Support the author
Even most of this development is done under opensource (GPL), I should apreciate donation for integration, development and materials : Donate
Author
Hamradio call F5OEO since 1995, electronic and computer science engineer. Interested in experimenting rather than communicating. Main interests : SDR, embedded platform (raspebrry pi), digital television (DVB).
Main projects
Useful explanation. The aim here is to prevent the helix interfering with the 10 GHz feed pattern.The best solution to that is not to try and challenge physics and instead use separate TX and RX dishes where compromises for dual band use do not need to be made.
I looked at adding 1, 2, 3 director elements to the POTY antenna to better suit longer F/D dishes, but it only gained a dB or so before I exceeded the limits of the student CST. Anything more complex was well beyond the capacity of student CST though if someone has access to the full version they could have a go. For example, I could not simulate even a short Helix.
Getting the phase centres in the right place is important, it's not quite right with the POTY but it's close enough. As HB9PZK suggested, a choke surround on the reflector is useful to clean up the backwards sidelobe. This improves the antenna noise temperature but is of no consequence for QO100 as the antenna is only used on TX, hence it's not there. I concluded the extra mechanical work in adding director elements for a dB of gain just wasn't worth it, but my dish is 0.6 f/D. Assuming Willi's simulations are correct, the efficiency is 50% and therefore absolute maximum gain would be less than 3 dB, realistically at best 2 dB. With a longer focal length, where the current feed is less efficient, it might be worthwhile, but what really kills this is the ready availability of 2.4 GHz power amplifiers. Until you get to high power, 2 dB more RF is a lot easier than improving dish efficiency from 50% to 80%.
On receive, I think we might realistically gain in sensitivity with smaller dishes by using a better LNB. The noise figure of standard LNBs at 10.5 GHz is not great, perhaps 3 dB. It should be possible to do much better. I have not seen many people using better LNBs, perhaps because it's so much more expensive.
Mike
Did you enable markers? It looks like you did so maybe restart?
Don't forget the influence of gravity, both in terms of time dilation and atmospheric tides.
You can still use VLC with minitioune via UDP in the interim. After setting the LAV codecs, the stuttering is gone. If it is only on the beacon I don't really care as I have seen the video often enough. My feeling was it impacted all H264 transmissions. The problem is it's hard to tell if issues are due to a bad transmission or on receive.
Glad to hear Jean-Pierre is working on using the VLC DLL. It's probably better long term. It would be helpful if the 64 bit version were an option as it doesn't seem to be possible to have both 32 bit and 64 bit on the same machine. This can lead to compatability problems with other software requiring the 64 bit version.
Another interesting prospect is if minitioune is using VLC, why can't it then work under Linux using Wine? Perhaps it can. Has anyone tried it?
Finally, would it be possible to give some love to Pipotioune?
LOTW is just too difficult to use. You need certificates for each PC you use and I have given up with it simply because it is so onerous to keep it current across many machines and laptops.
