Quote from DL4KAL

Hallo Peter,

erstmal vielen Dank für die Arbeit, die ihr für die Satellitengemeinschaft leistet. Kannst du schon einen Zeitrahmen nennen, zu dem der neue Sendemischer verfügbar sein wird? Ich habe den Empfangsmischer bereits bestellt und würde gerne den passenden Sendemischer dazu betreiben. Sollte die Entwicklung / Produktion jedoch noch längere Zeit in Anspruch nehmen, würde ich mich vielleicht für eine Alternative entscheiden.

73 aus Bonn

Wilhelm, DL4KAL

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Hallo Wilhelm,

Soweit ich weiß läuft die Bestückung der ersten Serie gerade, die dann noch einmal getestet wird...

Ich erkundige mich noch einmal und schreibe dann hier... es kann aber nicht mehr lange dauern.

oe3cbs: Inwiefern großzügiger? An welchen Eingangspegel hast Du gedacht? Ich kläre das auch..

73s Peter

Oha.. die TCXO+GPS Variante ist gerade ausverkauft

Aber keine Sorge.. es ist noch genug da... die Kollegen stellen immer nur kleinere Teilmengen ein, um nicht gleich erschlagen zu werden...

Also bis Weihnachten sollte es alles klappen, falls noch jemand ein Weihnachtsgeschenk sucht..

Hallo Thorsten,

es handelt sich um dieses Display:

https://smile.amazon.de/AZDeli…I2C&qid=1574021264&sr=8-1

Der neue AMSAT-DL QO-100 DownConverter Version 3d ist nun im Shop bestellbar.

Es gibt 2 Varianten:

1. OCXO
2. TCXO+GPS

Die OCXO-Variante bietet mit 20 ppb eine sehr hohe Stabilität und sehr geringes Phasenrauschen. Ein GPSDO ist hier nicht erforderlich und nicht vorgesehen, da es das Phasenrauschen sogar verschlechtern würde. Besonders wichtig bei DATV (DVB-S2), wo das Phasenrauschen sehr viel ausmacht.

Wer eher einen hohen Wert auf extreme Frequenzgenauigkeit legt, insbesondere für extremen Schmalbandbetrieb auf dem NB, für den ist TCXO+GPS die beste Variante. Aber auch DATV funktioniert damit gut.

Da ein OCXO aufgrund der Stabilität wesentlich teurer ist als ein TCXO mit GPS, sind die Preise gleich.

modifizierte LNB's

Wir haben größere Mengen LNB's beschafft, die wir jetzt noch umbauen lassen wollen.

Demnächst im Shop erhältlich!

OLED Display

Das OLED-Display ist optional und nicht im Lieferumfang beinhaltet, da nicht unbedingt zum Betrieb erforderlich und vielleicht auch nicht von jedem gewollt.

Display wollen wir demnächst aber auch noch im Shop anbieten.

Weißblechgehäuse

Standard Weißblech Gehäuse vom Schubert: 74*111*30mm (Art.Nr. 9)

Hinweis in eigener Sache

Wie auch schon auf der Mitgliederversammlung angesprochen, hier auch noch einmal der freundliche Hinweis, dass wir den Shop ehrenamtlich führen. Daher bitten wir um Verständnis, falls wir Fragen nicht immer sofort beantworten können. Manchmal kann es auch zu ungewollten Verzögerungen durch berufliche oder private Dinge kommen..

Der Shop erwirtschaftet keinen Gewinn. Mit den Einnahmen finanziert bzw. unterstützt die AMSAT-DL auch kleinere Projekte, wie z.B. die Antarktis QO-100 Station, oder auch die Bodenstation in Bochum.

nur eine schnelle Antwort, da ich schon auf dem Sprung nach Bochum bin:

OCXO mit GPSDO? Nicht sinnvoll...

Die OCXO Variante ist ganz bewusst nicht für die Synchronisation mit GPS konfiguriert, da man sonst das optimale Phasenrauschen des OCXOs beeinflussen würde:

Es gibt allerdings die Möglichkeit die GPS Daten (Standort, Uhrzeit) auch in der OCXO Version darzustellen, sofern man ein OLED Display hat. Das ist vor allem im Portabelbetrieb hilfreich."

LNB-Umbau für den neuen DownConverter

Mit dem neuen Konverter ist es nicht mehr erforderlich den LNB auf TCXO umzubauen, sondern die Referenz kommt direkt aus dem DownConverter, zusammen mit der Spannungsversorgung über das selbe Koaxialkabel.

Der Quarz wird ausgelötet und die 4,7uH Drossel (oben recht), sowie ein Saugkreis (150pF und 330nH) eingebaut.

Ein besseres Bild, dann auch ohne Deckel kommt noch.

Wir wollen später auch umgebaute LNB's kostengünstig im Shop anbieten.

So.. ab nach Bochum..

Thanks for your explanation Jörg, which puts it into a different view point.

As long as the Guidelines are respected in terms of bandwidth and power, everything should be fine and such experiments are welcome.

Sometimes I wish in general that there would be more "respectful" operating practices recognizing that this is a satellite linear transponder with limited resources and not just another short wave band or terrestrial radio.

By this I mean also more understanding and interrest in efficient modulation and coding techniques for satellite communication over a linear transponder.

Yes, we have a lot of bandwith, but the RF power is shared with all users,

Indeed there are a lot of new ham radio stations never heard or practizised amateur radio satellites before.. so more education will be required too.

When I read Ed's comments I was first wondering what is the benefit of FreeDV when occupying double bandwith for a return channel which is idle while the other person is speaking? That is even more bandwidth than a standard SSB QSO.

Anyhow, I think with your explanation this topic can be closed.

With regards to the spanish Pirate, with a lot of "silent" support of the community the person has been 100% identified. He even has a Facebook account.. That's the same person illegaly transmiting SSTV on the millitary fleetsat satellites.

Unfortunatly the authorities are a little bit slow, but we hope with help from URE and IARU the issue can be handled. We are currently also seeking advice from ITU.

But still suprising me that we radio amateurs were able to track down the pirate, that other "organisations" have not been able to do all the years before...

Der neue AMSAT-DL QO-100 DownConverter V3d

Hier nun der erste Preview...

Die Beschreibung ist auf unser Webseite unter https://amsat-dl.org/der-neue-…qo-100-downconverter-v3d/ zu finden.

Auf der Mitgliederversammlung am 9./10. November zeigt Stefan DG8FAC die ersten Muster und steht für Fragen zur Verfügung.

Preise werden dann auch dort bekannt gegeben.

Die Fertigung läuft jetzt an und nach der Mitgliederversammlung wird man den vor-bestückten Bausatz im Shop in 2 Varianten bestellen können (siehe Beschreibung). Wie beim vorherigen Modell müssen nur die Buchsen noch eingelötet werden.

Quote from F4HDK

Another topic about "point 2" I’ve not understood the "narrow band SDR" that you propose, inside the satellite. If you want to capture 100kHz RF bandwidth at uplink side, then you need more than 24bits x 100kHz= 2.4Mbps for IQ samples of each channel, for 12bits IQ sample resolution, to the downstream. This induces a huge RF bandwidth need at downlink (~2MHz with QPSK) compared to a pure “bend pipe” solution (~100kHz). Therefore, unless I have not understood something, I don’t think that it’s a good idea.

Hi Guillaume,

you are absolutely right! I did this long ago and did not re-check, only circulated internally where nobody noticed this mistake either Maybe because we were also thinking in parallel about "virtual channels" with demodulation and regeneration, for example with 2.5 kHz BW and demodulator for SSB, PSK, etc. FM-Uplink, other modes with more BW indeed, etc.. Onboard demodulation would indeed save a lot of bandwidth.

However, the idea to use a DVB-S2X only Downlink was lately driven by the fact that it would have a lot of advantage over an analog "bent-pipe" transponder. Mainly no need for drift compensation and abuse of uplink power would not have any effect. But it indeed also has disadvantages..

On the other hand, a "STELLA" kind of Linear Transponder would probably even make more sense for SSB, CW, etc. This concept originally came from Howard Long G6LVB for P3-E and we are currently designing some new Hardware for a LEO satellite.

But thinking more about it, it would in fact fit very well for a GEO...

So perhaps a "bent-pipe" transponder with plug-in STELLA functionality and a separate DVB-S2X Downlink, but with DVB-S2 Uplinks and "regeneration"...

I still need to learn more about NPR, it's protocol etc..

There is also some development going by our team member Mario Lorenz DL5MLO regarding extremely narrow band DVB-S2X via QO.100, He was able to successfully receive the upper PSK FEC telemetry from the beacon just with an LNB directed to the satellite. So I hope this development can also give additional input..

STELLA: Satellite Transponder with Equalizing Level Limiting Adapter

73s Peter

At least we can try to push things into the right direction this time..

AMSAT-DL (as part of the ARex Team) is also involved in the NASA Artemis Lunar Gateway activities. Some proposals have been submitted to ESA, also linked to AMSAT's expertise in general.

https://amsat-dl.org/esa-deep-space-gateway/

Achim DH2VA is representing AMSAT-DL in the regular meetings and two years ago Achim already proposed link calculations and station setup with lessons learned from P4-A/QO-100 ground-station equipment. Which is the "easy sat" now..

ISS and the Lunar Gateway will also be covered on Sunday on our

AMSAT-DL Satellite Symposium 9./10. November in Bochum.

DJ7WL As Kurt wrote in his first posting, it's an "WebSDR" running on a Linux system and you can access it in the home network locally with a Web browser on any computer including Windows 10.

Dear Guillaume and all,

thanks for taking this discussion up again.

I realized that I missed to go more into details and should have added a few more points what I was really thinking about.. Sometimes I have too many things in the head too

Usually there is more datarate needed in the downlink rather than in the uplink.

As you already mentioned MF-TDMA with several low rate uplinks and one common highspeed downlink, which could be an continuous DVB-S2 stream. For example our already existing DATV Beacon. Or comparable to the PACSAT satellites many years ago, where you had one continuous downlink and several uplinks channels..

Actually I had two different things on my mind:

1) A kind of PACSAT BBS or HamNet access

as described above...

2) A successor for P4-A which would replace the Analog Linear Transponder Downlink by a regenerative digital transponder with a single DVB-S2 downlink.

Part of the Uplink would be still "linear" as it is for SSB/CW/etc., but just like a remote SDR which will stream the "passband" down as I/Q data on the DVB-S2 downlink.

The DVB-S2 Downlink would always run constant power, no more problems with stations over-powering the uplink. In the example above the full NB uplink passband could be segmented into several channels with own AGC or "STELLA" leveling of the uplink signals..

So more Uplink power does not mean more Downlink power.

No "under-performing" receive station. Either it works or it works not.

No GPSDO needed on the DVB-S2 Downlink, just a standard LNB would do..

Indeed such a system requires some amount of onboard processing power, but the cooling and electrical power would be available.

This could be a next generation transponder and indeed we could try it on the ground first, very similar to 1) by having several low rate channels received in Bochum and encapsulated into the DVB-S2 downlink..

Well.. everything is in very early stage, still brainstorming

But also thanks to QO-100 we see a lot of interesting developments on SDR and DVB-S2 technology..

Not so many years ago, nobody would have thought what's already doable today..

What do you think about it?

73s Peter

Alexandru OZ9AEC recently twitters the following polar plot from OZ7SAT on telemetry frames received from LEO satellites:He asked: "Can you explain why most telemetry is received at elevations between 10° and 40° ?" (this is the yellow and red area in the plot)

If you read carefully what I have written before, you will quickly find out why and how an optimal antenna pattern should look like... additionally taking the slant range into account

Indeed the answer is, that the LEO's will spent most of the time below 40° Elevation...

Quote from PA3FYM

Rules which can't be enforced are useless rules.

They can be enforced easily by just taking away our permission to transmit there in case they worry about interferences due to "sloppy" transmissions... We have seen that before..

We are only secondary and some countries might be "sensitive"..

But indeed they might not come to visit you and verify what antenna you are using. But still this should not be ignored... The Spanish regulator obviously had some reasons for adding this requirement in the latest permission rules. Maybe they want us (when in Spain) to "concentrate" the transmitted RF energy in the direction of the satellite instead of "polluting" our surroundings..

Hi Dave,

just experimenting with different kinds of Omni directional antennas optimized for LEO satellites and getting some interesting results

I already started with LEO's long time ago, OSCAR-6 and OSCAR-7, etc., UoSAT OSCAR-9, UO-11 DCE Gateway and PACSAT's, but at that time I was already using high gain antennas with AZ/EL rotator. When OSCAR-40 stopped working, I removed all my 2m/70cm antennas when they got damaged in a storm Also somehow lost interest in LEO's and did not put something up again..

When I was already working on QO-100/P4-A and planning my antenna for it, an LEO OSCAR satellite opportunity came up (which I can not describe here for usual reasons). I wanted to find out which kind of antenna could be a good one for simple ground stations.. So when I installed my QO-100 antennas, it was a good chance to put something up again to see how it goes and also to try different antenna types.. many reports on these antennas are contradictory and there is no clear overview.

There are lot of things to take into consideration, which you already know..

• LEO satellites spent most of the time at mid and lower elevation, that's where you want to have antenna gain!
• Overhead passes are seldom and quick when overhead, i.e. only little time spent there and slant range is shorter overhead, so this should be compensated with less antenna gain.. no antenna gain needed here...
• And indeed you want to have it circular polarized with a "kidney" shaped pattern..

Turnstile does have a lot of nulls and not such a nice pattern as QFH, but QFH antenna pattern is not so good at lower elevations and wasting too much gain in Z direction.

Indeed, both antennas can be "tweaked", but you need an antenna range to find the optimal pattern.

I use the FOX Cubesats and the Fox Telemetry Analysis tool, as it allows to print nicely the received signals strength plotted in AZ/EL as mentioned earlier in this threat.

As you can see in an earlier post here, I was running the TA-1 antenna for 1 year. It works nicely at lower elevations, but does have some bad nulls at higher elevations.

I have exchanged it now with an Eggbeater and will run the same experiment again over the coming winter There is also an interesting article from Jerry K5OE about his Eggbeater II which was very popular in the early time of PACSAT's and LEO's.. not sure why it got almost forgotten..

73s Peter

and you loose 3dB due to linear polarization...

BTW: In Spain this antenna would be illegal for QO-100 Uplink as it has < 22.5dB gain and less directivity...

still interesting to see how this panel antenna performs in reality...

Schweizer Koordinaten

english: https://en.wikipedia.org/wiki/Swiss_coordinate_system
german: https://de.wikipedia.org/wiki/Schweizer_Landeskoordinaten


Maximale Sendeleistung: PEP

according to the footnote of the official BAKOM document..

The peak power at the transmitter output is the maximum average power that a transmitter may deliver during a period of high-frequency oscillation at the highest peak of the modulation envelope (PEP).

Die Spitzenleistung beim Senderausgang ist die Durchschnittsleistung, die ein Sender während einer Periode der Hochfrequenzschwingung bei der höchsten Spitze der Modulationshüllkurve maximal abgeben darf (PEP).

QO-100 in Switzerland

For the sake of completeness... sorry in Swiss-German

HB9 - BAKOM Sonderbewilligung für Es’hail-2 / QO-100

Seit dem 15.Nov 2018 ist der erste geostationäre Amateurfunk-Satellit Es’hail-2 in der Umlaufbahn und dürfte schon bald für die ersten Verbindungen der Funkamateure zur Verfügung stehen.

Für Verbindungen mit Es’hail-2 brauchet es nicht nur eine spezielle Technik, sondern auch eine Sonderbewilligung vom BAKOM. Da doch eine gewisse Gefahr besteht, dass andere Dienste in diesem lizenzfreien 2.4 GHz ISM Band (Industrial, Scientific and Medical Band) gestört werden könnten, will das BAKOM die Standorte dieser Satelliten-Stationen kennen.

Ein Antrag kann an das BAKOM an folgende Mail-Adresse gestellt werden. kf-fk@bakom.admin.ch

Das Gesuch zur Nutzung des Frequenzbereichs 2400 – 2410MHz als Satelliten Uplink muss folgende Informationen enthalten:

• Rufzeichen und Konzessionsnummer

• Standort (Ortsbezeichnung, Adresse)

• Schweizer-Koordinaten (z.B. 2'600’000/1'200'000, neue Koordinaten) Keine Google-Koordinaten!! (Umrechnung im Internet möglich)

• Antennengewinn (dBi)

• Antennenhöhe über Grund (m)

• Richtung der Antenne (°)

• Elevation der Antenne (°)

• E-Mail Adresse

• Telefonnummer unter welcher der Operateur während dem Betreib der Anlage erreichbar ist

Die Sonderbewilligung ist kostenlos und wird unbürokratisch und zügig bearbeitet.

Jedoch sollte man sich bewusst sein, dass sie auf Zusehen hin vergeben wird, und jederzeit wieder zurückgezogen werden kann, falls sich Schwierigkeiten ergeben sollten. Es ist also ratsam, die Anlage so zu planen und zu betreiben, dass mögliche benachbarte Funkdienste in diesem ISM-Band nicht gestört werden.

Die Sonderbewilligung berechtig zu einer Sendeanlage mit einer Leistung von maximal 100 W PEP. Dies sollte für alle möglichen Betriebsarten über Es’hail-2 reichlich genügen.

Wir wünschen euch viel Erfolg mit diesem neuartigen Satelliten.

Bernard Wehrli, HB9ALH

Vorstand, Ressort BAKOM und Antennen

2019-09-10-ALH

An International Space Station school contact has been planned with participants at Science & Technologie e.V. / event: Science Days, Teningen, Germany on 17 Oct. The event is scheduled to begin at approximately 12:03 UTC. The duration of the contact is approximately 9 minutes and 30 seconds. The contact will be direct between OR4ISS and DN1EME. The contact should be audible over Germany and adjacent areas. Interested parties are invited to listen in on the 145.80 MHz downlink. The contact is expected to be conducted in English.

Story:

Science Days

The Science Days is the first German science festival, which was founded in 2001. Around 15.000 students of different school levels attend this science festival every year. The Science Days are located in Germany's biggest family park "Europa-Park" in Rust and are organized by Science & Technologie e.V., a non-profit organization.

GHSE School

The questions for the contact come from students of GHSE. GHSE stands for "Gewerbliche und Hauswirtschaftlich-Sozialpflegerische Schulen Emmendingen" in Germany and offers education with a special vocational focus on industry, ecotrophology as well as applied social sciences. The industry-focused part of the school was already founded in 1836 and has since been evolving into a wide variety of educational directions for all sorts of students with all kinds of different talents and interests. Our campus includes a large workshop-area. GHSE offers educational qualification ranging from a "Hauptschulabschluss" (certificate of secondary education) up to the "Abitur" (general qualification for university entrance) and is also a vocational college within the German dual education system. There are currently around 2100 enrolled students at GHSE. 45% of them attend the "Berufsschule" (vocational college). Around 16% are found in the applied social sciences field. The rest is distributed among other areas such as care-giving, information technology, management, mechatronics and several other fields.

Participants will ask as many of the following questions as time allows:

1. Can you describe what the feeling when the rocket was launched?

2. What were your first impressions when you arrived at the ISS?

3. How did your family react when they learned about your trip into

space?

4. Which time zone are you using on ISS and do night and day light

changes play a role at all for your working day?

5. How does it feel to float in space and how do you like zero gravity?

6. We've heard that there are no windows in direction of outer space.

Why is that and how does it feel like to see the stars from the

station or during an outdoor mission?

7. The laws of which country are applicable in the ISS and in general

there in space and do you have to pay tax for the money you earn in

space? Who pays your wages?

8. Are there any scientific discoveries or important experiments which

have been recently made?

9. Can see you visible changes occurring through the climate change?

10. Who makes decisions regarding, for example, who is allowed to do a

space-walk? The space agencies or the commander?

11. Have you or another astronaut ever lost something on the ISS?

12. Do you think the Bosch reactor will be successfully implemented

soon and how will it affect the ISS?

13. What do you think about space tourism?

14. Are private conversations with your family also allowed or do all

conversations have to be carried out through the space agencies?

15. Was it worth it to put so much work into aerospace, now where you

see the results or are you disappointed?

16. What is the weirdest thing you have on the ISS?

17. What do you do in order to prevent injuries and what medical

equipment do you use in the case of an emergency?

18. What did you regret or miss when you flew into space?

19. What was the biggest damage you had to repair in the ISS and what

happens with an ISS module if it's irreparably damaged?

PLEASE CHECK THE FOLLOWING FOR MORE INFORMATION ON ARISS UPDATES:

Visit ARISS on Facebook. We can be found at Amateur Radio on the

International Space Station (ARISS).

To receive our Twitter updates, follow @ARISS_status

Next planned event(s):

1. Istituto Comprensivo Statale "Diego Valeri", Campolongo Maggiore,

Italy, direct via IQ3RW and

Istituto Comprensivo Ladispoli1, Ladispoli, Italy, direct via

IKØWGF

The ISS callsign is presently scheduled to be IRØISS

The scheduled astronaut is Luca Parmitano KF5KDP

Contact is go for: Sat 2019-10-19 10:27:13 UTC

Watch for live stream from IKØWGF side of the contact:

or directly on AMSAT Italia youtube channel:

https://www.youtube.com/channel/UCkJ8IFmfTO-pUkVFNrUXIcg

About ARISS

Amateur Radio on the International Space Station (ARISS) is a cooperative venture of international amateur radio societies and the space agencies that support the International Space Station (ISS). In the United States, sponsors are the Radio Amateur Satellite Corporation (AMSAT), the American Radio Relay League (ARRL), the ISS National Lab and National Aeronautics and Space Administration (NASA). The primary goal of ARISS is to promote exploration of science, technology, engineering, and mathematics (STEM) topics by organizing scheduled contacts via amateur radio between crew members aboard the ISS and students in classrooms or public forms. Before and during these radio contacts, students, educators, parents, and communities learn about space, space technologies, and amateur radio. For more information, see http://www.ariss.org.

Thank you & 73,

David - AA4KN

A look at the block diagram sometimes says more than 1000 words

There is ony one single S-Band Uplink antenna dedicated to us and RHCP was the best choice.

NB and WB path are completely independed, separated after the antenna via redundant paths.

There is also only one dedicated feed for our X-Band Downlink.

Since any commercial LNB use H/V polarization, this was the perfect solution to connect both NB and WB to the same feed and same antenna. Like on the commercial Sat-TV downlinks, we could also use the same frequency or overlapping frequencies just with different polarization.

We always propagated the use of Dual-LNB in case you want to receive both NB and DATV at the same time and it costs almost nothing...

Quote from G8UGD

It is about wireless to me, but I bet it is possible to do and something that Amsat as a governing body could operate for schools and colleges if they wanted to show the technology, and my questions were actually genuine. How would you authenticate licenced operators?

Yes, I was somehow joking.. but technically it would be doable...

We don't have authentication in the real hamsphere either, except for announcing our callsigns.. so a perfect simulation