Posts by 5B4AKV

    Dear all ,

    I've posted also on the other forum/part part with adalm pluto and the 40 Mhz ref and I still get drift on my TX and RX ...

    So is there a definite way to know what part could be of issue ?

    Maybe my signal is "hot" ?

    Thank you in advance


    Okay so in esence is mostly operator practice and keeping the TX ON all the time , and since both stations use Full dublex ( aka monitor their own TX signal) you can just make it much faster and harmonized .. and just talk right after the other person ?
    Right ?
    well its an interesting mentality given that most of the times the conversation between 2 stations its almost crystal clear audio it could be done :D


    Dear All ,

    Hello ,

    As far as I understood is to use split operation. and there for full dublex
    station A constantly RX (Freq A-20khz) and TXs (FREQ. A) on a split frequency (constantly)

    and station B does the same inverse split and also RX (FREQ A) and Tx's (FREQ A-20KHz) at the same time. (constantly)

    So both stations allegedly will talk full duplex at the same time BUT occupying double the bandwidth aka 2 TX stations on 2 channels of 2.6KHz for 1 QSO !

    This is not a mayor problem as its done in situations where crazy pileups happen. So its possible but Whether or not It is worth to be implemented because you will have half the bandwidth to operate ( in regards to, other stations IF everyone employs this very "mode" / "type" of operation ) the bandwidth of the SAT is finite and not infine.

    This is my understating of what everyone is trying to do I suppose if my understating is wrong feel free to correct me :D

    Thank you in advance

    73 DE 5B4AKV


    Dear All ,

    I know this was answered before too ( tried to find something but to no avail) , But I am a bit perplexed so if someone can shed some light on things I would be happy. (rev C possibly )

    I have the Amsat down converter with the 40mhz output. I measured it all good. I made my cable(2 pin header to hoax to sma ) and directly connected it to the Adalm Pluto(external ref in port). But now it seems even more unstable than before.

    When I type this :

    # fw_printenv ad936x_ext_refclk <--

    ## Error: "ad936x_ext_refclk" not defined <--I get this ( what ? )

    I tried to enable external reference for the pluto.

    # fw_setenv refclk_source external
    fw_setenv ad936x_ext_refclk „<40000000>”

    fw_setenv ad936x_ext_refclk_override 40000000
    fw_setenv xo_correction 40000000

    then reboot.

    and now my transmission is drifting like crazy even with the external reference. and I can even see it before with the TSXO ( default config on the adalm Pluto I had no issue. ) (very rarely I was drifting that much )
    something like this :

    and at some points even worse.

    I hope someone can drop me a hint ,

    Thank you in advance

    5B4AKV , Alex

    Dear Mr.DM5RM Roland ,

    Yes I do know this is accurate because I got such values under testing conditions, and of course calculating them as you just did ,

    The issue is how can I just transport audio or some other method that does not need so much bandwidth ,

    like for example KiwiSDR web console ( based on open web rx) or openweb rx or SDRplay TCP method ? .. ?

    any ideas ? ( how to do it / implement it ? )

    Thanks in advance


    Dear All ,

    I have my station setup as a networked adalm pluto.
    When I used it on my local network my SDR console clocked at 100MBits network traffic almost saturating the Pluto network interface.
    Even going at 550khz radio bandwidth the network bandwidth needed was around 20mbits ..

    So my question is is there any other way to operate the pluto that is a more network lenient mode ?
    aka.: Does not consume this crazy amounts of network bandwidth for simple operation ( SSB voice) .

    please see attached.
    [Blocked Image:]

    Thank you in advance


    Dear All ,

    I had my fun on QO-100 with voice. I am most of the times quite busy to get on the satellite and also doing it remotely seemed to be a challenge ( issues with audio mostly) but I will deal with that soon.

    Never the less I would like to know IF there is something else to contribute as a standby ground station for the satellite , maybe telemetry , or automated tests ? or something to make my setup useful while I am not actively using it ? something to contribute back to the group / hobby

    I hope the experts would shine some light on this request ,

    Thank you in advance


    An Attenuator about 10dB should do the trick.

    Make a PI attenuator : 100 Ohm to Ground , (33+39=) 72 Ohm in series with the Signal , 100 Ohm to Ground

    73, Martin

    For now , I will try to make the beacon tracking with the software.

    Later after I become more proficient I will try to make it work .. I have a ver B that is a quite difficult version to deal and mod .. so time will tell.

    Dear All ,

    Also An other question ,

    After reading a bit more carefully
    the Adlam Pluto expects something with 1V P-P(MAX i've read it on the forum) :…-clock-to-the-adalm-pluto

    from the manual I see :

    10 MHz and 40 MHz output:

    [Blocked Image:]

    The following reference signals are available:

    10 MHz REF OUT: solder eyes for SMA connector, 10MHz 50Ohm, 0dBm, sinus\\. 40 MHz REF OUT: 2-pin connector, 40 MHz, 3Vpp CMOS level, square wave, left signal, right ground.


    Is there something or somehow to lower the voltage ? from the board ? or I have to make a voltage decider my self ?



    Dear All ,

    I found something not as detailed as I hoped but it should do for now.

    Here it is.…m-pluto-f5oeo-plutodvb/4/


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    This video at the end with the power mod.

    Now regarding the converter mod I need to find out the exact output reference

    Thank you in advance


    Dear All ,

    please bare with me, Thins may have being answered already and I can't seem to find it.

    A few months ago I have a full hardware guide to do all the mods on the ADALM Pluto and Now I can't seem to find it I was searching all day today.

    So Now I have my "AMSAT-DL QO-100 DownConverter V3d" all soldered up and ready to go , BUT

    I need to get the reference from this board and feed it to the ADALM Pluto.

    And I am not sure how do it properly since I've lost the guide I found a few months back.

    Thank you for all the help in advance.

    73 DE 5B4AKV

    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.


    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

    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

    Dear All ,

    I've made on order on the E-shop , I had an account fully verified and now non of my credentials are recognised and therefor I can't see my order ( neither email or username can be seen )

    I've tried to recover it with forgot password but still shows that no such email or username exists ... I am confused :'(

    I hope someone can help me, I've emails support with no answer ,

    Thank you in advance