NJ6N’s Amateur Radio & Electronics Blog
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Alpha Delta Coax Switches
I have one primary HF antenna, a Hustler 6BTV (6 band trap vertical). I was using an Alpha Delta 4-port coax switch to switch the antenna between my K3, K2, and coax that I use on the workbench. This morning when I listened for the SOARA 40 meter net, signals were very weak. SWR was…
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Tivo Power Supply Repair
I’ve got a very old Tivo, an HRI-250. Last week we had a major power outage that lasted 12 hours. When the power came back on, my Tivo did not. It had been having some over-heating problems, so I wasn’t surprised. Investigating further, I found that I was missing some of the supply voltages. The…
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Arduino KISS TNC
Mobilinkd (http://www.mobilinkd.com) is the producer of very compact and capable bluetooth enabled KISS mode TNCs that are used with APRS applications on Android, iOS, Windows, and Linux, and Mac OS. Their original prototype was built using the Arduino platform. On their website, they provide breadboard descriptions of various TNC designs including an Arduino based KISS…
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PowerPole Power Panel
SOARA has “battery box” building events every so often. The idea is that you build a portable container with a battery, cigar lighter socket, power switch, volt meters, and Anderson PowerPole connectors that you can use during an emergency. I have designed and/or printed and built several such breakout boxes. I built a Pelican case…
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YAdmHS – Yet another digital mode hot spot …
I got to thinking about how I could make a thinner MMDVM based multi-mode hotspot with a Nextion display. I decided to try mounting the boards next to each other instead of plugging the MMDVM board into the Pi ZeroW board. I also wanted the case to have rounded corners. Here is what I came…
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Tip Organizer Tip
I’ve got way too many different Weller soldering Iron tips for my temperature controlled Weller ET and PT soldering irons. It finally occurred to me that I should create a tip organizer for them. I drew one in Sketchup and printed on my Hictop 3D printer.
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APRS on Raspberry Pi
About a decade ago I bought a TNC-X from Coastal Chipworks. I used it for a fill in digi for Laguna Niguel for a while. I bought the X-Track and X-Digi add-on boards for the TNC-X as well. Unfortunately, when I tried to add a larger 5V regulator to power an external GPS, my dyslexia…
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Kenwood TM-742 Backlight Repair – with LEDs!
Kenwood TM-x42 tri-band mobile radios have six 6.3 volt incandescent bulbs arranged in three pairs of two bulbs each to light up the display. Eventually the bulbs burn out and since they’re wired in series, they go out in pairs. I recently replaced the backlight bulbs in a friends TM-642 with white LEDs. I used…
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Fun with OpenRepeater / SvxLink
In the Summer of 2017, I built an EchoLink “link node” using a Raspberry Pi 2 Single Board Computer, 900MHz quad-core ARM cortex A7, 1GB RAM, 10/100 Ethernet. The software is called “SvxLink” named after the call sign of the author, Tobias, SM0SVX. Information about the svxLink application can be found on Github at: http://www.svxlink.org…
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Fun with Digital Voice Dongles and Multi-Mode MMDVM Hotspots
Quite a long time ago, Robin, AA4RC gave me a DV Dongle that he had recently developed. It was amazing! It enabled something that wasn’t possible before. With the DV Dongle connected to my Mac, I could monitor the activity on remote D-STAR gateways and talk to folks on the world-wide the D-STAR system without…
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