QO-100 setup with AMSAT-DL parts, will this work?

  • Hi!


    I am thinking of getting into the wonderful world of satellites and the search for transverters got me here. ;) I am a newbie on anything higher than 70cm, but willing to learn. So I read lots of websites on the subject and came up with the setup below. And yes, long post, so my apologies in advance. ;)



    As you can see it consists of a UpConv6W and Downconverter V3d. I intend to use an Icom IC-7000 as the TRX (would love to buy myself an IC-9700, but funds...). That also means I need to go single-band simplex, switching between the up- and downconverter. That is where the RF-sensing MFJ-1707B comes in (suggestions for other brands welcome).


    The upconverter feeds the POTY, the downconverter is fed by the LNB and the 10MHz reference is also sent to the upconverter for stability.


    What do I expect this setup to do?

    1 - let me TX on 435.5 MHz with 1 to 2 Watts of power and get into the uplink of the QO-100, for either SSB or NB digimodes

    2 - let me RX at 435.5 Mhz (as set by the setting on the downconverter) from the downlink of the QO-100

    3 - the 435.5 Mhz frequencies need to be in sync, since the IC-7000 does not have the ability to do a linked split, where both VFO A and VFO B change at the same time. I need an IC-9700 in satellite mode for that.

    4 - no full duplex, so no real time monitoring my signal in the IC-7000. But I can use the Goonhilly websdr and compare the PSK beacon strength (shown as -72dB) to my own signal and avoid overpowering the uplink that way.

    5 - everything can be built into a case, attached to the off-set boom for the LNB, keeping all cables nice and short there and I only need to connect 12v power and the coax for the IC-7000 70cm signal. If the case is plastic, the GPS antenna for the GPSDO can be installed inside the case, a metal case means putting it on the outside.

    6 - only minor soldering to be done, as I am not an experienced fine solderer. The odd connector is not a problem (and required in this setup), but SMD is not an option for me.

    7 - be stabil enough, but I do not expect rock stable signals as the IC-7000 will drift on 70cm (not noticeable there, but probably on the uplink). I can fine-tune the VFO if needed.

    8 - if I buy an IC-9700 in the future, I can remove the 1707B antenna switch, add another coax cable and reconfigure the downconverter for either 145 or 1290 MHz and go full duplex. If needed I can then also feed the 10MHz reference to the IC9700, but I probably need some way to split it between the upconverter and the 9700.

    9 - I do not intend to do DATV and go on the WB transponder.


    Questions:

    - #3 is something I cannot find in the documents, the upconverter is listed as configurable at "435 MHz", but as both are from AMSAT-DL I expect them to be in sync. But am I right?

    - for 435MHz on the upconv6w I need to put a bridge over the low-pass filer (17). The documentation does not list from where to where the bridge needs to be put. Is that listed somewhere?

    - is this a setup that can work? Will it meet my expectations?

    - suggestions on cases to mount this in?

    - any suggestions on improving this setup?


    Thanks for your time and advice!

    Robert - PC5E / AC2E / SP20EJ

    Icom IC7300, Icom IC7000, Anytone D578UV, Anytone D878UV

    Edited once, last by PC5E ().

  • Hi Robert,


    Welcome on-board!


    Sorry for asking, but does IC7000 not allows continous receiving on HF while transmitting on 2m/70cm?


    Or you use the IC7300 for RX (28 MHz for example) and the IC7000 for 70cm TX ?

    If both transceivers have remote control, even synchronizing them would be no problem...


    73s Peter

    Peter Gülzow | DB2OS | AMSAT-DL member since 1983 | JO42VG

  • Hello Robert


    Welcome in the wonderful world of OSCAR's.


    That also means I need to go single-band simplex, switching between the up- and downconverter. That is where the RF-sensing MFJ-1707B comes in (suggestions for other brands welcome).

    A golden rule of satellite operation is that you work in Full-duplex. So you can hear yourself and control your downlink like your signal strength, and very important, your modulation. Many Pluto-users doesn't it and have a rough modulation. But with the converters of AMSAT-DL you are on the save side. Then you have 2 coax cables. That also means you have to work on 2 ZF bands. Best is RX on 2m and TX on 70cm with your Icom TRX.


    For more questions please ask.


    73

  • Thank you for your answers!


    The IC7000 can do a band-split (TX on 70 and RX on 2 or even down to 80m), but the VFO's will not be linked. So to QSY I need to change both VFO's by hand. I could do RX on the 7300 (with the nice waterfall to watch my signal), but then I still need to manually adjust both VFO's. Unless there is a CAT program that does this for me, then there is no problem. ;)


    I know I can link two Icom sets by CI-V, but they will then be on the same frequency. And since the 7300 cannot do 70cm and I cannot TX on 10m or so (bands that both the 700 and 7300 have) into the upconverter, that wil not work. And the IC-7000 is not full-duplex, So even if I would take the manual VFO adjustments for granted, I cannot monitor my own signal. Same goes for the 7300, not full duplex on different bands, only split operation.


    And yes, I know full-duplex is a golden rule (but also read that it is mostly for LEO's and it might not apply for QO-100 that strictly...), but I can do that with the Goonhilly SDR as a pan-adapter. Not as good as with a 9700, but spending almost 2000 euro's for a slight improvement could be a bit overkill...


    I am looking for a setup that can be my entry into the world of satellites, using as much of the equipment I already have, but without needing to adjust two VFO's at the same time. The setup above will cost me over 1000 euro's, so adding 2000 for a 9700 is not what I would like right now. If satellite operations becomes a favorite part of my hobby, I then might buy myself a 9700, but we are not there yet. ;)


    P.S. a reply in German is no problem for me. I understand it quite well, but writing it comes with some errors.

    Robert - PC5E / AC2E / SP20EJ

    Icom IC7300, Icom IC7000, Anytone D578UV, Anytone D878UV

  • And yes, I know full-duplex is a golden rule (but also read that it is mostly for LEO's and it might not apply for QO-100 that strictly...)


    I don't know where you heard that..


    The official transponder bandplan and guideline says:

    "Full-Duplex operation is mandatory (you must be able to monitor your own downlink while transmitting!)"


    I know that some people ignore it or will start to argue, but that doesn't make it better ;-)

    And depending on the WebSDR is also somehow cheating and not state of the art...


    You could still use your IC7300 for RX and IC7000 for TX, it's not so difficult to calculate and tune manually.. many people are just doing that..


    Alternatively you could simply use SDR-Console, an cheap RTL-SDR dongle for RX and let SDR-Console tune your IC7000 via CAT-Interface...


    73s Peter

    Peter Gülzow | DB2OS | AMSAT-DL member since 1983 | JO42VG

  • I read it here on the forum. ;) But I can use the 7300 for RX, it is just an extra coax cable and setting the selector on the downconverter to a different setting. And the SDR Console also sounds like an option, linking both bands. I will look into this.


    With that change in mind, would the setup above work as expected?

    Robert - PC5E / AC2E / SP20EJ

    Icom IC7300, Icom IC7000, Anytone D578UV, Anytone D878UV

  • A new sketch is not a problem.


    But I am also thinking of using a Pluto and SDR Console, it seems that SDR Console can sync the two VFO's over CAT. That would make life much easier and free my 7300 for HF. I could then use my 7000 for TX only.


    Now I just need to figure out if I will use the Pluto for both RX and TX or just for RX. I can stop using transverters for RX and/or TX and just need amplifiers for the TX path.


    Back to the drawing board! :)


    Any comments on the full-Pluto setup? Drawbacks?

    Robert - PC5E / AC2E / SP20EJ

    Icom IC7300, Icom IC7000, Anytone D578UV, Anytone D878UV

  • It can be done very easily and cheaply via QO100 operation. No transceiver is required, no transverter. Only a Pluto SDR, an amplifier stage depending on the dishsize and an LNB for reception.



    My portabel station for QO100:

    [Blocked Image: https://s3.amazonaws.com/files.qrz.com/j/dd9fj/rtabelpluto_PA_LNB_Fernspeisung3.jpg]


    The reason for the relatively high transmission power is only the small portabledish and 10m cable..
    With 2Watt direct behind a 1.2m dish, you will get the same result in tx (and better in rx)


    [Blocked Image: https://s3.amazonaws.com/files.qrz.com/j/dd9fj/40er_Portabelspiegel.jpg]


    Only 40cm dish with 10 Watt input in a homemade poty patch antenna.

  • indeed here is the official "golden" rule :-)

    https://amsat-dl.org/p4-a-nb-t…and-operating-guidelines/


    In theory your idea might work, but I think nobody tried this particular configuration yet...

    I also understand that not everyone wants to use a computer.. and the Pluto needs to be modified with external GSPDO.

    For sure with a combination of the IC7000/IC7300 you shall have a nice&clean signal too.

    Peter Gülzow | DB2OS | AMSAT-DL member since 1983 | JO42VG

  • And Pluto-users should also control if there bandwidth of signal is not wider than 2.7 kHz. As I know (read in this forum) it can be adjusted <2.7 kHz with SDRconsole. Otherwise the bandwidth is default 3 kHz wide. Correct me if I'm wrong. I already heard terrible modulations over the transponder after my CQ. I would be very thankful for a clean modulation with my TS-711E RX. Otherwise I "fiddle" with the RIT knob. ;)

  • dd9fj , your setup looks nice and simple! Do you have a list of the individual parts? The Pluto and SG Labs PA I can identify from the picture, but not the rest. I would also like to use a relatively small dish (40 to 60 cm) and thus need a bit more power than a larger (90 to 120 cm) dish. How much power is needed with your small dish?


    I am now thinking of going the Pluto route. Pluto and all other parts in a waterproof box near the dish (to avoid loss of power) and IP remote access from SDR Console to the Pluto. Then I also only need 2 cables: power and network. I used ADALM PLUTO Full Duplex Transceiver For QO-100 - YouTube for inspiration. It is cheaper than using transverters, full-duplex, but also needs more attention to configuration and a computer for the SDR Console.


    At my location in JO22xx I can "see" the QO-100 from my garden, by pointing a dish parallel to my home, if the various apps are correct. That is good, if the sat was only visible from the front of my home, I need a permit to place an antenna...

    Robert - PC5E / AC2E / SP20EJ

    Icom IC7300, Icom IC7000, Anytone D578UV, Anytone D878UV

  • I would recommend going Pluto or LimeSDR and using SDRConsole. The price is very similar but the Lime is a lot more frequency stable. This setup is a lot better than a traditional transverter route and also sets you up for the future. Additionally you do not need to lock your LNB to a reference, the software can compensate for drift by tracking the beacon, though locking is best if you can. That saves buying a GPS reference until you know you want it.


    However not everyone likes software defined radio as there are no knobs to twiddle. For flexibility it can't be bettered and it's considerably cheaper too. You will need a bit more power with a small dish, I would not recommend below 60cm for SSB. Aim for 10W to be sure it's sufficient and there just so happens to be a 20W PA available at a nice price. With a 1.2m dish you could get away with a 5W PA, much cheaper but of course there is the larger dish needed. It's a trade off driven by your individual circumstances.


    Mike

  • At my location in JO22xx I can "see" the QO-100 from my garden, by pointing a dish parallel to my home, if the various apps are correct. That is good, if the sat was only visible from the front of my home, I need a permit to place an antenna...

    The direction of QO100 is almost exactly the same as Sky TV (UK) so getting such a permit, should you need it, might not be so hard. Nobody is going to be able to tell the difference without test gear. :)

  • Thanks for your reply. I will also look for the LimeSDR, if that is more stable. And if the SDR Console can lock onto the beacon, I will try that first (in addition to a better TXCO in the Pluto if I use one). Can the Lime SDR be used over an IP network, like the Pluto? I can probably use it over a long USB cable, but rather use a network connection.


    I don't mind SDR, as I am an IT guy for work. ;) But I do like physical knobs. And I intend to use the QO-100 setup for JOTA too, and a physical device with knobs looks better to scouts.


    From a price point SDR is way better indeed. Physical full-duplex setup will cost about 3000 euro's, since I do not have an IC-9700 already (2/3rd of the cost...). SDR full-duplex setup is way under 1000 euro's.


    As for the dish, I will go for 60cm for portability and aim for 10W output to the POTY.

    Robert - PC5E / AC2E / SP20EJ

    Icom IC7300, Icom IC7000, Anytone D578UV, Anytone D878UV

  • Hello Robert

    in the upper picture the GPS module is wrongly plugged on the downconverter. It must be rotated through 180°.

    Also check the connections from the LNB to the downconverter that the ref. frequency output ( WB in ) is connected to the correct output of the LNB. Because with our mod. LNB is the connection the other way round.


    73 de Michael

  • DD5ER , the LNB connections were mixed up, I know. And the GPS module was not meant to be in correct orientation. So your remarks were correct. ;) But since I posted that picture I changed from a simplex transverter solution (beacuse of cost and no full-duplex) to an SDR solution. No picture yet, but I intend to create one if I get the components identified.


    HB9SKA , I read somewhere that people put 20dB attenuators between the LNB and the Pluto SDR (not to overload the RX), so biger is not always better, I guess. On the other hand, adding attenuation is better than adding an amplifier and the only drawback to a bigger dish is less portability.

    Robert - PC5E / AC2E / SP20EJ

    Icom IC7300, Icom IC7000, Anytone D578UV, Anytone D878UV

  • Okay, the promised graphic for the PlutoSDR setup:

    Not drawn is the Pluto network converter and the USB OTG Y cable with 5V power input and the 90cm off-set dish. And I might need some sort of attenuation in the down link signal if it overpowers the Pluto RX.


    I want to use 12/13.8v as the only power supply, so I use DC/DC converters to get to the needed 5.5v (Pluto, CN0417 PA), 14/18v (LNB) and 24v (PA).


    I am still looking for a 739MHz band pass filter, to clean up the down link signal going to the Pluto.


    If I get this all righ, I now designed a networked QO-100 full-duplex SDR setup that produces about 10W output for the up link (enough for SSB). Cost will be below 1000 euro's (all parts shown are just over 700 euro's and I need some coax, a dish, a case and some assorted stuff).


    Questions:

    - is the setup okay? Suggestions welcome.

    - is the placement of the 2400MHz band pass filter in the up link in the correct place? I want the up link signal to be as clear of unwanted RF as possible.

    - I think reading the LNB would need 14v for the correct polarization, am I correct?

    - the LNB is unmodified, so not as stable as I want. Putting in another TXCO is possible, but beyond my soldering skills. However I like the stainless steel POTY. ;) Can you recommend another LNB/wifi combination that is more stable and equally weatherproof? Or will the sync of SDR Console with the beacon remove the need for a stable LNB?

    Robert - PC5E / AC2E / SP20EJ

    Icom IC7300, Icom IC7000, Anytone D578UV, Anytone D878UV