NJ6N’s Amateur Radio & Electronics Blog

  • Quansheng UV-K5

    Quansheng UV-K5

    I have been a fan of the firmware modified Quansheng UV-K5 handhelds for a while now. The base radio is not bad and the features added by Hams through firmware modifications have been very useful. The radio is available through the usual sources including AliExpress, Amazon, Ebay, etc. The radio is known as the Quansheng…

  • Malahit/N7DDC ATU-100 EXT Antenna Tuner 

    Malahit/N7DDC ATU-100 EXT Antenna Tuner 

    This is a 100 watt HF/6m Antenna Tuner kit sold through the usual consumer sites like Amazon, Ebay, and AliExpress. It was apparently designed by N7DDC. I happened to run across this tuner kit while looking for something else on Amazon. At $30 or so, it was cheap enough to take a chance on and…

  • Automatic Power Off

    Automatic Power Off

    I have used an APO-3 automatic power off unit in my vehicles for many years. I recently needed to add a second one for my rear-facing dash camera in my truck and wondered what it would take to design and build one myself. I decided to use an Arduino Nano as the microcontroller since I…

  • 3D Printed Dipole Support

    3D Printed Dipole Support

    for portable or fixed use I had some left over aluminum tubing from other antenna projects and thought it would be useful to build a 10 meter dipole out of it. I needed a way to attach the elements to a block of wood and attach the block of wood to a TV antenna mast.…

  • Code Practice Oscillator

    Code Practice Oscillator

    My Brother Dana, K6NR, needed a CW oscillator for an upcoming presentation on Morse Code. I didn’t have a code practice oscillator, but I have plenty of PARTS! So I set out to build one. I Googled for Code Practice Oscillator Schematics to get some ideas and found this design. It’s a clever project that…

  • More MMDVM hot spots

    More MMDVM hot spots

    I needed to replace a broken hot spot case recently. At first, I reprinted my original ugly square ZumSpot + Nextion design from years ago. I was happy to be able to print it using ABS with my new printer. But I got to thinking how my newer design, a rechargeable ZumSpot+Nextion Hot Spot could…

  • QRP Labs QDX 5-band Digital Transceiver

    QRP Labs QDX 5-band Digital Transceiver

    Way back in April of 2023 I bought a QDX digital transceiver from QRP Labs. QRX stands for “Qrp-Labs Digital Xcvr”. I thought it would be fun to take with me on trips. I finally got around to building it in August, 2024. The instructions are very good with excellent diagrams and illustrations on how…

  • Tait T855 Rx & T856 Tx module setup

    Tait T855 Rx & T856 Tx module setup

    Our high-level 440 and 220 repeaters on Santiago peak use modular rack-mounted Tait radios. Our 440 band repeater uses a T855-20 series 1 module for receive and a T856-20 module for transmit. The transmitter is capable of 25 watts or better, but we have configured it for 10 watts output to drive an external TPL…

  • Digital Voltmeter/ Ammeter

    Digital Voltmeter/ Ammeter

    I found some small, inexpensive digital voltmeter/ammeter panel displays recently and thought it would be nice to have an inexpensive inline meter that I could use to measure various devices. I designed a case and by version 3, I think I’ve got a nice little gadget. The connectors on the back of the meter module…

  • External PL control for VXR-5000V/RLC Club Repeater

    External PL control for VXR-5000V/RLC Club Repeater

    A few years ago, I upgraded SOARAs primary VHF repeater at our Temple Hill site to a “new to us” Yaesu/Vertex VXR-5000R repeater. The new VXR-5000V repeater features an internal CTCSS decoder and encoder and a basic repeater controller. Around the same time, I replaced the half-duplex GM-380 link radio with a pair of Motorola…

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