Category: Ham Radio
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mini USB Power Box
portable USB power from 12VDC Recently, my brother told me about a problem he had with a USB power adapter that was causing a lot of RFI on VHF in his mobile setup. It’s not hard to imagine how inexpensive 12V to USB adapters could cut corners and cause interference. I found some higher quality…
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Adding Five-Band LPF to the U3S
Some time ago I build the Ultimate 3S QRSS/WSPR transmitter from QRP Labs. It came with one low pass filter. I chose the 10meter LPF because I was originally thinking of using the beacon transmitter for the SOARA K6LLL 10 meter CW beacon and the U3S is a great fit for that job. Once I…
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OpenWebRX+ on AtomicPi
OpenWebRX is a software defined radio (SDR) web application that enables users to listen to analog and digital signals received by an attached SDR device through their web browser. As the name implies, it is a receive only application. I had recently acquired a great single board computer to run this on. OpenWebRX can demodulate/decode…
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SweetPotatoPi?
I’m not sure what you might want to call it, but my goal was to learn what the component parts of the very popular suite of Digital Voice applications that make up “Pi-Star” were, and how they interacted with each other. I wanted to use non-Raspberry Pi hardware since Raspberry Pi hardware is scarce and…
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Using BF888S UHF Radio w/ svxLink
Continuing my experimentation with cheap radios to create svxLink nodes, my next victim is the BaoFeng BF888S. For about $25 including tax you can acquire two BF-888s radios with accessories. These radios are incredibly cheaply made but should be suitable to use for a low power analog node. They are UHF and cover 400-470 MHz…
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Inexpensive SvxLink Node
I wanted to build the most inexpensive SvxLink “node” or “station” I could using off-the-shelf parts. I bought an inexpensive BaoFeng “S9Plus” (it says “UV-S9X3” on the side) radio on Amazon for $28. For the computer system, I used a Raspberry Pi 4 that I already had, however, I also found a Raspberry Pi B+…
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A 19″ rack rail case for Masters Communications RA-xx Radio Adapters
We’ve got a couple of these interfaces installed at our repeater sites and one is also providing a remote SvxLink/EchoLink node for our Santiago Site via link radios. There are already 3D printed cases available for these adapters but none that I’ve seen have any mounting tabs. I designed a case that has a row…
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Full Duplex Repeater Linking
Many years ago, SOARA Repeater and Technical folk fabricated 19″ rack shelves that contained Motorola Mitrec radios that were modified for full duplex operation. The shelves were fitted with “flat pack” band reject duplexers and hardline to interconnect them to the radios. The UHF linking band was monitored for some time using an Icom PCR-1000…
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More Fun with 3D Printing
I continue to be amazed at how much you can do with 3D printing technology. When I need an enclosure for something, it’s really nice to be able to design the perfect fit for my project. When a part breaks, I can often design and print a 3D part to replace it. 3D printing is…
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Hendricks BITX20A SSB Transceiver Kit
Many years ago, circa 2007, I bought a Hendricks Bitx 20A, 20 meter QRP SSB transceiver kit at the Pacifcon conference in San Ramon, CA. I bought the main kit along with the machined and painted Ten Tec case and KD1JV digital frequency display kit. I figured I would build it over a holiday break…