Posts by ra3apw

    Hello All,

    my question is about using SDR Console (V3.0.27) and Adalm Pluto (Rev. D) with an external 25MHz reference.

    Pluto configuration for external reference was done according to section “Alternative reference frequencies”.

    The modification went well which was confirmed by software and hardware (Pluto’s buffer of the external reference signal (LTC6957) turned on and internal 40 MHz TCXO turned off; 25 MHz reference signal comes to the XTALN pin of AD9363)

    After Pluto is connected to the computer the device is seen as a memory but when trying to “Start radio” it says that the device was not found.

    It was tested on two computers and with different external reference frequencies - 25 and 40 MHz.

    Maybe something needs to be changed in SDR Console settings with which Pluto worked fine before the modification?

    73 de Karen, ra3apw

    Lucio, thank you for the advice - I will check these variants shortly.

    Regarding the clone production - I don't know the reason why they decided to move to new version. May be AD was not happy with this clone...

    If he doesn't answer or has no infos then please wait for RA3APW's measurements.


    today after 40 days of waiting for my order I received the following from Ebay seller: "The factory has stopped production. A new version is being developed later". Therefore the clone test measurements are canceled, sorry.

    I will try to place an order for the standard AD ADALM Pluto rig - anybody can recommend the right place ?

    Hi Peter,

    I can agree that the IC-705 is not the best solution for LEO satellites but in my opinion it is quite suitable for the QO-100.

    We have to monitor the downlink and we can do it in the following ways:

    1. WEB SDR - requires the Internet and we do not like it - removed

    2. monitor on the transceiver in sat mode - this is not the case in the IC-705 - removed

    3. monitor on a separate transceiver

    4. monitor on a separate receiver

    If I know correctly nowhere in the rules does it say that we should monitor satellite’s downlink only on the same device from which works in the uplink. Right?

    If so both of the options 3 & 4 are suitable.

    In my QO-100 transverter I have two RX outputs from LNB - one goes to the 739 -> 144 converter and then to the satellite transceiver (like IC-9700) , and the second output goes to an external VHF receiver for monitoring - for example, the AOR-3000 VHF/UHF scanner or standalone SDR RX (without PC).

    73 de Karen, ra3apw

    Besides the frequency, the power is also unknown!

    Almost all parameters of this unit are unknown and if they are known then they require verification. :)
    Similar situation was with EDUP 2400 MHz amplifiers and with other RF products from Aliexpress.
    I am planning to do a measurement test in my laboratory when the parcel will be at my table.

    I placed an order for this device a week ago. As I understood from the description, the board has a U.FL connector for an external reference frequency. However, the parameters of the external reference signal (frequency) are not yet known.

    Two new boards have been made for full duplex RX mode:

    1. REF25 board - reference 25 MHz signal for LNB's PLL from OCXO
      More details -…uv2js-4o6T8pG8vPmIAVRvFvw
    2. RX739 board - RX down converter 739/144 MHz
      More details -…Um9VQP3XH4roXb9YMsVafXObo

    Summary - QO-100 tranverter has six boards kit:

    • TX up converter (TX_UPC)
    • Reference source (OCXO)
    • Attenuator, RF switch & PS (ATT_PTT_PS)
    • 20W/2400 MHz power amplifier (PA20W)
    • 25 MHz reference for LNB's PLL (REF25)
    • RX down converter 739/144 MHz (RX739)

    More details about STC7013 -…iek6YFcfGJ6DpB8_yfV5gp0BI

    Sorry text in Russian - please use Google translator.

    Hello Karen

    This is not what I'm looking for, I think this are factory values. My input are about 400 mW from the up-converter's output via a short pigtail cable.

    Thanks anyway

    Hello Thomas,

    if your up-converter has 400 mW output it will be good to put 6 dB attenuator between up-converter and EP-AB003 to be in linear mode.

    Hi, thanks for the answers. My plans are to write my own Python scripts. Also to use 7470.exe as plotter emulator. At this Link it has software that can be used. My thought about Ethernet is that it will be available from any PC local or remote. Applications ideas are phase noise, alan deviation, real time web spectrum monitor of HF-UHF.

    Hi George,

    look at TimeLab from John Miles, KE5FX and

    It seems you can find most of your wishes there including Prologix GPIB (both versions GPIB-USB/GPIB-Ethernet) support

    73 de Karen, ra3apw


    I plan to buy a Prologix GPIB Ethernet adapter. Any suggestions ?


    Depends on the measuring application. I use Prologix GPIB about 5 years. I had both - NI and Prologix. Prologix works great for me with the R&S FSQ8 for measuring phase noise and with Pendulum CNT-91 for measuring Allan deviation. NI has been sold as he did no more in the applications I needed.

    73 de Karen, ra3apw

    Hi Paul DD8PL,

    thank you for the link.

    I found there the next interesting explanation regarding Lime SDR mini external reference:

    LimeSDR uses an ADF4002 Phase Detector/Frequency Synthesizer to synchronise the 30.72 MHz VCTOXO to an external reference. There is a U.FL connector on the LimeSDR board used for the external reference, the supported frequency range is 20MHz to 300Mhz. Frequencies lower than 20MHz are supported as long as the slew rate is greater than 50 V/µs.

    73 de Karen, ra3apw

    Hi Alex SV8QG,

    Correct - LimeSDR mini has a dedicated U.FL connector on board for external reference.
    But taking into account that we need one more reference (25 Mhz) for LNB PLL's I usualy do it with one good reference.
    In this case make one more 40MHz reference for Pluto is not a big problem - Allan deviation will be good from OCXO and phase noise level should not be very low.

    73 de Karen, ra3apw

    Hi David G0MRF,

    thank you for the useful link with Ole OZ2OE LimeSDRmini's measurements.

    I’m not sure that SMD 2400 MHz bandpass filter will remove spurious products near the carrier but -55 dBc level seems not bad.

    It remains to find a similar picture of the spectrum for ADALM Pluto.

    Agree - Pluto looks better - but the difference of TX power output and the price between these two radios is not significant.

    73 de Karen, ra3apw

    Hello All,

    I'm between choosing ADALM Pluto and Lime SDR Mini.

    My question is: did anyone make comparative measurements of the output spectrum of these two devices on 2400 MHz with span 100 and 1000 MHz in the TX CW (FM) and SSB modes?


    Karen ra3apw

    Hi Claudio,

    Thank you for the link, I read it with interest.

    I unfortunately do not have any experience with this device.

    In my opinion, in order to make a decision about the choice of a reference signal source, first of all, you need to know two parameters:

    1. Allan deviation
    2. phase noise.

    I did not find any information on this in either the article or in the lot's description.

    Karen, ra3apw