Victor X-Ray Juliet Info
Designer, maker and licensed radio amateur operating under the callsign M7VXJ. This site documents my ongoing experimentation with radio telegraphy, satellite reception, electronic engineering and related projects.

I also create computer generated animation as silico.studio and design bespoke 3D printed products, which are avalable for purchase from physis.shop.

Radios   
   Yaseu FT-857     Yaesu FT-818      Yaseu FT-4X        LilyGo T-Echo     RTL-SDR       Hack-RF        T1000-E  
Antennas                      Diamond VX30N [2m,70cm]                        DIY V-Dipole [137 MHz]                        Parabolic [1.7GHz]                        EFHW [7, 14 MHz]                    
           
9th January 2026
Meteor M2-4
L-Band HRPT


    With Storm “Goretti” causing weather alerts and disruption across Europe, I attempted to capture imagery via Meteor M2-4 as the satellite passed directly overhead from south to north just after midday. The centre of the storm system is clearly visible over the Netherlands.

    4th January 2026
    Meteor M2-4
    L-Band HRPT


      The Russian Meteor-M2 series of meteorological satellites transmit high-resolution imagery (HRPT) of the Earth at around 1700 MHz, commonly referred to as the L-band. Receiving these transmissions provided an ideal opportunity to test my newly built L-band antenna and rotator.

      I tracked Meteor-M2-4 using SatDump, which handled scheduling, recording, processing, and directional antenna control. The result is the most detailed and highest-resolution satellite imagery I’ve received to date, making it possible to clearly see features such as snow cover across the Alps and northern Scotland.

      1st December 2025
      AZEL Antenna Rotator 
      Build Log


        After successfully receiving VHF satellite signals using static antennas, I decided to go a step further and build an antenna for L band (1 to 2 GHz) reception, along with an automated rotator that can point the antenna in any direction in the sky. 

        The plan is to make a system which can automate the tracking and reception of satellite signals and would hopefully improve reception from fast moving satellites and those using higher gain antennas or spot beams which require more directional accuracy, as well as open up tracking options outside of the VHF band.

        After much research I decided to build an antenna rotator, combining jbryrn’s AZEL rotator with t0nito’s 1.7 GHz HRPT helicone antenna along with wcdreisbach's AZEL Tripod Mount. Most of the components were 3D printed from their designs, I created some of my own components all of which can be downloaded here. The servos, bearings and the threadded rod were recycled from an old Ender3 printer.

        To control the rotator, a Raspberry Pi 3A computer with a Waveshare Stepper Motor HAT (B) manages the power and controls the rotator’s servos. A Python script running on the Pi establishes a local TCP/IP server using the Hamlib protocol, which allows software like SatDump to remotely control the rotator, adjusting its azimuth and elevation.

        This allows satellite tracks to be scheduled based on TLE (two line element set) data, with the management of both the frequency and the processing of the received signal being automated. 

        After the construction of the rotator, the balancing of antenna and the inital tests using the TCP/IP server; the next step is to attempt to both physically track a satellite and downlink its L-Band radio signal simultaneously.

        15th November 2025
        QPSK Constellation Plot
        Artwork

          Quadrature Phase Shift Keying (QPSK) is a digital modulation method that encodes two bits of information by shifting the carrier between four distinct phase angles.

          QPSK efficiently encodes information into analog signals and is used in many applications. I first encountered it when decoding weather imagery from the Russian Meteor-M satellites; their “LRPT” image downlink uses QPSK modulation.

          As part of an ongoing video project and as a way to better understand how it works, I made this animation that visualizes a QPSK constellation plot, showing how symbols cluster into four phase states and how noise/spread affects demodulation.



          3rd September 2025
          Tinkpad T490
          Build Log

            I was lucky to be gifted a busted ThinkPad T490 laptop with a broken screen. Today I got around to replacing the LCD panel.

            Having fixed a number of laptops in the past, I can say the ThinkPad is by far the easiest to service.

            I’ll also be installing an NFC (Near Field Communication) board once the parts arrive...

            2nd September 2025
            Hack-RF One
            3D Printing

              The HackRF One PortaPack H2 is a small radio device that can send and receive signals across a wide range of frequencies. Which I mostly use it for tracking aircraft ADS-B transponders.

              When in the field, I store it in the Pelican 1040 Micro Case. This case is waterproof, dustproof, and crushproof, which makes it ideal for carrying sensitive electronics. The only problem is that, without something to hold the device in place, it can shift around inside and accidentally press the buttons.

              To solve this, I designed a simple 3D printable mounting plate that attaches to the lid of the case. It keeps the HackRF One PortaPack H2 securely in place and stops it from moving around. It’s a small tweak, but it makes transporting the device much easier.

              You can check out the printable file here.


              3rd August 2025
              Noaa 19 APT
              137.100 MHz
              Hack-RF

                These weather satellite images from the NOAA-19 satellite show the approach of Storm Floris from the Atlantic Ocean.

                The image quality is better than in my previous attempts, thanks to the upgraded HackRF SDR (software-defined radio), which offers a significant improvement over the RTL-SDR, when using the same V-Dipole antenna tuned to 137mhz.


                18th July 2025
                Seeed Colab
                Meshtastic
                T1000-E

                  Over the past few months, I’ve been collaborating with Seeed Studio through their Co-Create program.

                  Together we are bringing two of my accessory designs for their T1000-E meshtastic device into mass production.

                  As of today, both the SenseCAP T1000-E Protective Case and the SenseCAP T1000-E Charging Puck are available for purchase directly from Seeed’s online store.

                  This partnership should simplify access for international buyers, especially those outside the UK, by reducing shipping costs and improving availability.


                  06th July 2024
                  Callsign Patch
                  3D Printing

                    I created a bespoke callsign patch using the multi-material feature of the Bambu X1 Carbon 3D printer, printing both black and white PLA within the same object.

                    I included a number of holes around the periphery of the patch so that thread could be used to more securely attach a strip of adhesive hook-and-loop tape to the patch itself.

                    15th May 2025
                    L-Band Satallite
                    Antenna

                      A while back, I picked up what I believe is the TP-Link TL-ANT2424B directional WiFi antenna. It’s a 2.4GHz grid parabolic antenna.

                      I bought it used and did not realise it was missing the feed-point reflector - the small assembly where the signal is actually focused.

                      Rather than write it off, I decided to take a shot at building my own replacement, with the intention of eventually tuning the antenna to recieve transmissions from L-band satellites.

                      I created a 3D-printed enclosure around the antenna itself and used aluminum plate to make the feed-point reflector.

                      Right now, it's a bit of a work in progress. I haven’t tested the performance with any proper RF tools yet, but I plan to do some testing to see how well it works in practice.


                      4th May 2024
                      Noaa 15 APT
                      137.000 MHz
                      RTL-SDR

                        With the National Oceanic and Atmospheric Administration (NOAA) announcing the de-funding of NOAA Satellites 15, 18, and 19, I set up a new capture of Satellite 15 as it passed overhead, using SatDump, a newly tuned antenna, and an SDR.

                        25th June 2024
                        Tracking Weather Satellites
                        137.000 MHz
                        RTL-SDR

                          After building a new V-Dipole using a 3D printed housing and panel mount SMA alongside a SAWbird LNA filter I was able to receive (noisy) APT images from the NOAA weather Satellites.

                          The amount of noise makes me think that there is alot more work to be done to isolate the radio from background EMF interference.


                          11th March 2024
                          Dipole Radiation Pattern
                          Artwork

                            Each antenna has a different radiation pattern, the images bellow show the radiation pattern of a dipole antenna. I was interested in creating the toroid of a dipole as there is certain quality to its convergence and symmetry.

                            These renders are aesthetic illustrations and do not portray any useful information, normally scientific visualizations would show dB levels as graduating hues, for this creation I was only interested in the geometric forms.



                            10th March 2024
                            Conversations Part I
                            Artwork



                              While visiting the City Art Centre in Edinburgh, I saw the artwork; ‘Conversations Part I’ by Kate Downie which visualises RF signals as bright lines of colour in contrast to a monotone backdrop.

                              It was my interpretation that the artists was representing the conversations that invisibly intersect the landscape between radio towers as a positive force that connecting people’s lives.
                               


                              11th Febuary 2024
                              Logbook
                              Yaseu FT-4X
                              I recently aquired my first 2m/70cm handheld transiever, the Yaesu FT-4X.

                              The first contacts I made eith it were picking up the RSGB news from GB2RS GM3HAM Lothians Radio Society as well as a direct 5,9 contact with GM4DTH on 145.525MHz.