Archive for category: Amateur Radio

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.) […]

JT65/JT9 not impervious to false positives…

January 20, 2014 | Amateur Radio | By: Mark VandeWettering

I haven’t had a lot of time to operate JT65/JT9, my preferred digital mode at the moment, but I often leave my receiver hooked up and monitoring the bands for reception reports. My wet-noodle of an antenna can usually pull in signals from about 40 different counties in the span of a week of monitoring. […]

IRLP/Echolink. Raspberry Pi. Baofeng. Cheap.

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

I love cheap hacks and cheap gadgets. Don’t get me wrong: I also like the expensive good stuff, but if you don’t have a clear idea of what you want and need, spending a lot of money on gadgets just isn’t in the cards. But if the gadgets are cheap enough, experimentation becomes possible for […]

JT65 vs JT9 (vs WSPR?)

December 31, 2013 | Amateur Radio, WSPR | By: Mark VandeWettering

For the last several days, I’ve been running the latest version of wsjtx using my RFSPACE SDRIQ software defined radio, and just logging the results. Previously, for most of my JT65 needs, I used JT65-HF, but I was interested in trying out the JT9 mode as recommended to me by numerous hams. JT9 uses a […]