AMSAT LNB with out 24MHz reference input will it work ?

1st Official Post

    Dear All ,


    Due to some unfortunate issues / situations I was not able to get he downconverter / reference board ( ordered it from amsat shop)

    and now I want to operate the QO-100 with the "DJ7GP V2 2.4 Ghz & 10 GHz antenna with LNB modified 24 Mhz AMSAT DL" I got from a secondary source.

    The question is is the LNB gutted completely ? or there is still a TSXO or PLL or crystal or something still inside of it ? so I can kind of work somewhat with the LNB in question ?

    Or if I power it up without a reference I will break it completely ?

    because I really want to operate this SAT but these issues with supply all of the the world make the situation difficult.

    Thank you in advance

    73 DE 5B4AKV

    Hi,

    i'm pretty sure the lnb WILL NOT WORK without 25 or 24MHz reference. If you can't wait, try any ordinary modern unmodified lnb. It will drift a lot and will not be accurate, but you can work the satellite. Most modern lnbs have a crystal built in and are fairly stable, but not perfect.

    73, Martin

    Quote from dm4im

    Hi,

    i'm pretty sure the lnb WILL NOT WORK without 25 or 24MHz reference. If you can't wait, try any ordinary modern unmodified lnb. It will drift a lot and will not be accurate, but you can work the satellite. Most modern lnbs have a crystal built in and are fairly stable, but not perfect.

    73, Martin

    That was what I was afraid my self. ( I was 99% sure this was the case)

    But Now next question I have a bullseye LNB ,

    how can I use the TX antenna of the moded LNB to get the transmission out ? because Its the only one I have TX capabilities ,
    together with the Bullseye LNB I can mount the one on top of the other ? I don't have a second dish to point to the SAT so that I can mount both LNBs on different dishes.

    In general this is a bad situation I got my self into.

    the next opportunity I have is in like 4 months.

    ;(

    Thanks for everything


    73 DE 5B4AKV

    Hi,

    well, you can remove the lnb from the DJ7GP antenna and replace it with your bullseye lnb. To do this, remove the plastic enclosure from the bullseye lnb and cut/saw off the feedhorn.

    Make sure no chips fall into the lnb through the holes for the 2 antennas .

    If you have a dish for broadcast tv , you may want to use the bullseye lnb offset like this:

    My first attempts to receive the bird was with an unmodified lnb. I just drilled a hole in the plastic cap protecting the feed horn and stuck it onto the tube of the patch antenna.

    Like this:

    Find an abandoned dish, any will do . 60cm is just right.

    The picture shows one of my first attempts with a dish i got from the junkyard. It even worked behind the colsed balcony door.

    If all this is not your cup of tea, you still can listen to QO-100 via WebSDR and only use the transmit capabilities of your DJ7GP antenna.

    In a later step, you add the receive capabilities once you got your downconverter.

    73, Martin

    Quote from dm4im

    Err... from reading your posts again and again, i get the impression you think you need the lnb together with the downconverter to TRANSMIT . No.

    What upconverter and what TX do you have?

    Sorry for asking....

    I do not need an up converter because I have Adalm Pluto. ( I have a pre-amp and an amplifier to get the 2.4Ghz out )
    Down converter I also do not need because Adalm Pluto can RX the Mixed output from the LNB at 739 MHZ aprox.

    So what I will eventually do is what you I think said to RX my self from the webSDR and TX from local and see how it goes.

    Or I can take my other big parabolic dish to RX the SAT but I have no idea how to change the LNB on that.

    I will try soon :D I will keep you posted thank you for everything guys :D

    Update . :

    My time run out at my QTH and it was time to go. at least I managed a snaky night to align the dish with the sat while I had some time.

    so I got an update also from AMSAT that the package its on it what with the reference board and the new LNB

    on the next visit I will panel mount everything seal it and set it to work via Ethernet. It will be an interesting project :D

    Slowly slowly.

    Thank you for everything.