Archive for category: Amateur Radio

Minor tweaks to Arduino Morse Sketch…

March 30, 2015 | Amateur Radio, Arduino, My Projects | By: Mark VandeWettering

Commenter Andy wanted a version of my classic code that could generate a tone instead of just blinking an LED. I mentioned that I had done this before, but frankly couldn’t find the source code, so I modified my existing program to implement the simplest possible tone: a simple square wave. Rather than using a […]

A 6M beacon using the NT7S’s Si5351 board…

March 9, 2015 | Amateur Radio, Arduino | By: Mark VandeWettering

This morning, the Tweeti-verse (I can’t believe I just used that word) informed me that Thomas, LA3PNA had constructed a VHF beacon using the Si5351, and I was tagged as somehow helping: VHF beacon with the Si5351. code: https://t.co/OkgZXKFSKc , video: http://t.co/hbZl9F76Aj based on code from @brainwagon @NT7S — Thomas S Knutsen (@la3pna) March 9, […]

Old Radio Publications available online…

March 4, 2015 | Amateur Radio | By: Mark VandeWettering

I like reading old books and old magazines. Luckily, the Internet is making a lot of that kind of material available online for free. A couple of quick links to some items I’ve found recently on the subject of amateur radio: Radio News was published from 1919 to 1959. PDF scans of every issue are […]

Partial Solar eclipse underway….

October 23, 2014 | Amateur Radio | By: Mark VandeWettering

Snapped with my iPhone, held to the eyepiece of a Questar equipped with a solar filter…

The Si570 and the Si5351

October 14, 2014 | Amateur Radio | By: Mark VandeWettering

Thomas’ talk about the Minima at Pacificon has got me thinking about building one of my own. I actually have quite a few of the necessary parts in my junk box, but lacked a few things, so I made a quick list and sent a quick order off to Tayda. Tayda has really good prices […]

A day at Pacificon…

October 13, 2014 | Amateur Radio | By: Mark VandeWettering

Pacificon is the local yearly hamfest, which took place at the Santa Clara Marriot this weekend. I couldn’t go for the entire weekend, but I decided that spending at least part of my Saturday amongst my fellow hams would be good fun, so I set my alarm to an annoyingly early time (for the weekend) […]

An antenna for receiving ADS-B…and velocity factor of RG-6

July 29, 2014 | Amateur Radio, Software Defined Radio | By: Mark VandeWettering

Allright, last night’s experimentation with the RTL-SDR dongle on my Raspberry Pi Model B+ was pretty successful. Incidently, I forgot to mention that this worked fine with the dongle plugged directly into the Pi, I didn’t need a powered hub. That’s pretty cool. Previously, I had experimented with decoding ADS-B signals from airlines. I thought […]

Hellschreiber Update…

April 7, 2014 | Amateur Radio | By: Mark VandeWettering

Scott Haley mentioned my old Hellduino post on Facebook: a simple project that used an oscillator powered by an Arduino to send Hellschreiber, a kind of simple fax mode invented by Rudolf Hell in the 1920s. I did this mainly as a simple test, inspired by Steve Weber, KD1JV’s “temp2morse” project. But unfortunately, that page […]

Digital ATV resources…

April 1, 2014 | Amateur Radio, Amateur Satellite | By: Mark VandeWettering

I’ve been doing a bunch of reading about digital ATV operations lately. I was originally motivated by hearing about the HamTV project aboard the ISS. Back in 2007, I got re-energized into ham radio by learning that for the 50th anniversary of Sputnik, the amateur satellite AO-51 would broadcast a cool message that I heard […]

Some continuing short bits on SSTV….

March 16, 2014 | Amateur Radio, Raspberry Pi, SSTV | By: Mark VandeWettering

Nothing too exciting going on, but minor bits of code and play have been done, so I thought I’d update. First of all, there is a program for decoding SSTV on the Pi, called QSSTV. I don’t have a proper sound setup on the Pi yet, so I couldn’t test it live on the air, […]

Additional Experiments with SSTV, with some ideas….

March 9, 2014 | Amateur Radio, Raspberry Pi, SSTV | By: Mark VandeWettering

Previously, I had written an encoder for the Robot 36 SSTV mode. I chose this for a simple reason: it appears to be the most common mode used in downlinks from satellites, such as the ARISSat-1. It’s not a bad choice, and presents reasonable quality in just 36 seconds. Today, I decided that I should […]

SSTV travels through the Ether! A minor success!

March 8, 2014 | Amateur Radio, Raspberry Pi, SSTV | By: Mark VandeWettering

So, this morning I played around a bit more with my Raspberry Pi code to try to see if I could make an SSTV beacon. The idea was to use two existing bits of code, raspistill and my own SSTV encoder (robot36), and glue them together with a small bit of Python. The code uses […]

The Baofeng BF-888S as an SSTV beacon?

March 7, 2014 | Amateur Radio | By: Mark VandeWettering

Yesterday’s musings about SSTV using the Raspberry Pi has me thinking about creating a little SSTV beacon using the super-inexpensive (less than twenty dollars with charger) BF-888S HT from Baofeng. It’s hard to imagine a cheaper HT than this: it doesn’t even have a display. It has 16 channels, and announces which channel you are […]

Some thoughts on SSTV and the Raspberry Pi…

March 6, 2014 | Amateur Radio, Raspberry Pi | By: Mark VandeWettering

Today I found an interesting Instructable on running SSTV on the Raspberry Pi. It uses an interesting bit of software which uses the Pi to directly generate an FM signal. Strictly speaking, I doubt this is a great idea without some outboard harmonic filtering, but it’s cool that it could be done. I recalled that […]

The Minima — A General Coverage Transceiver

February 15, 2014 | Amateur Radio | By: Mark VandeWettering

A while ago, Bill Meara from Soldersmoke brought Ashar Farhan’s new design, the Minima to my attention. The Minima is a general coverage transceiver which has a lot of cool features. It’s a superhet design which is Arduino based (actually, it incorporates a bare bones Arduino, which is little more than an Atmel ATMega328 chip.) […]