Making QLRS lightest

This is quick guide, showing how to replace SMA connector by tiny U.FL used for 868MHz FrSky antennas, and make really small Qczek LRS RX.

The hardest past of modification is SMA connector removal. I did it using hot air…

Next very important thing (don’t forget about it) is removal part of RF signal trace. It must be done, if you left it under new connector, the capacitance will make your RF signal week. So just cat it as shown below.

Then you can solder new U.FL connector. Please check which pins should be soldered, because sometimes it has 4 pins, 3 for ground 1 for signal.

OK, almost done, add LED, capacitor and shrinking tube.

With FrSky antenna is only 7.3 grams.

And remember to secure connector …

35 thoughts on “Making QLRS lightest

  1. Not sure if this blog and the YouTube channel are run by the same individual; but I figured I would post here just in case. At least this way I can leave my email without it being seen by everyone. Thank you for your time and help with FPV.

    My reply to your message on the YouTube channel:
    Wow!!! That would be absolutely amazing! I’ve just started in FPV and have found it to be incredibly fun and exciting. The amount of information is astounding and the kindness of people more experienced in the hobby is equally incredible. How do I send you a private message? Or make my reply private? Haha.@Krzysztof Kuczek

      1. Good day! please help, I really need your help. how can I connect 433 modules to radiolink at9 control equipment. really looking forward to hearing from you.

  2. Hello, I am following your LA Lora project, but I have a problem like flashing a module E32-868T20S I can not find RESET pins and SWIT please can help me. Thank you.

  3. Hi, I’m trying to configure telemetry gps (ublox) and for frequency 868 I don’t see version, can you compile for this frequency? I would like if this version for NMEA GPS is possible.
    Thank you.

    1. Just done, check download page.
      But it’s not tested, please let me know if it works 😉
      NMEA will not be supported due to out of flash memory problems 😉

  4. Hi, thank you for the ublox version, it works, but the satellite numbers do not appear. Another question, “transparent” telemetry, how does it work? What enters a bit as it comes out?
    Thank you.

  5. Hola, como entendido la telemetría “transparente” puede enviar “bits” lo que entre, y en otro lado venta lo mismo, ¿no? Lo que pretendo si usted puede compilar una versión para 868 como “master y slave”
    para transmitir telemetria NMEA con una sentencia $ GPGGA yo greo puede funcionar. Porque teñgo un rastreador que trabaja con telemetria NMEA. Gracias

  6. Sorry ,hello, as I understand the “transparent” telemetry can send “bits” what enters, and elsewhere the same sale, right? What I intend if you can compile a version for 868 as “master and slave”
    to transmit NMEA telemetry with a $ GPGGA statement I can work. Because I dye a tracker that works with NMEA telemetry. Thank you

      1. Hello, the required rate is 100Hz / 150Hz for “Transparent” telemetry. Thank you.

        1. but I’m talking not about refresh rate, but about no of bytes which must be send/recive every second 🙂

          1. Hello, sorry it’s 100-150 bytes for “transparent” telemetry, for NMEA with a sentence and 5Hz. Thank you.

  7. Hello, my question was about whether you can explain what telemetry is “Transparent”.

  8. Please tell me when the firmware for the modules E32-915T20S 100mw will appear? These modules are already widely distributed, and there is still no firmware. Modelers will be very grateful if you release this firmware.

  9. Kris, hello from ru! Thx for project, im build 433 and 868 versions, work perfecly.

    Im need little help, may be im may wrote to your email?
    I want use e32-433 as people search tracker, and need start example code for sx chip and stm pins inside this module.
    If you may help me this info – thanks! My email worked.

  10. Hello, I hurried, I purchased modules with a capacity of 100 mW 915 MHz for receivers, is it possible to flash them with firmware for 1 cotton modules ?, there are no firmware for 100 mW. Can I flash them with a version for 869 m? Hz I would be grateful !! Sorry for my english.

  11. Dear Kris! What is the capacitor value? Between + and – I think. Rhis is nowhere in the building tutorial or anywhere.

  12. Hi,
    really like your work!
    I am planning to build something similar based on a teensy 4.1

    I am a bit confused with a few things, may I ask you a few questions?

    Thank you in advance!
    Best regards from Austria

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