Wednesday, March 14, 2018

New APRS Node up!

So I've finally deployed the APRS node for full time use at the local Sheriff's department. The node was built on a RaspberryPi 3 connected to my Icom 8000 with a Signalink Interface. It's running Direwolf 1.4 for both digipeater and iGate functions.

I sent some time getting it configured to pass traffic back and forth between the RF channel and the Internet. I used a couple of local filters to only pass items within an 80km radius of downtown Henderson.  I let the unit run 24/7 at my house for about a month just to make sure it was stable and reliable. I had good results with it.

The whole unit was going to the SO, so I wanted a package that was compact and neat looking. The Pi also including the Adafruit 2.8 touch screen which I picked up from Fry's about a year ago for $35. A trip to Lowes led me to an $11 outdoor junction box. I cut a whole for the screen and mounted the Signalink and the Pi inside so they wouldn't move around. I routed the cables through a hole I drilled in the back.

I mounted the radio on top using the stock mounting bracket. I left a USB keyboard dongle in the Pi so I can used a miniature keyboard (made for use with a TV set-top box) as an input.

The biggest hurdle was trying to find a way to log into the Pi once it was deployed. It would be behind a firewall on a guest Wifi network. I eventually found ngrok (thanks to my brother-in-law). Ngrok is a small program that facilitates the tunneling of a variety of services to ngrok's servers. Then I can connect to ngrok and track back to my Pi. The basic level of service is free and plenty for my needs.

I deployed the unit and its been working great. From my home or office I can log in, update, restart or reconfigure it as needed!

Friday, May 27, 2016

Cell phones cause cancer...Uh?

UPDATE: The Wall Street Journal has published a more balanced (although not completely hysteria-free) article on the study.

Cancer from RF? Buckle your seatbelts folks because the roller coaster is just getting started. Like an early teaser trailer for an upcoming blockbuster movie, the first few details from a new study looking for a connection between radio waves and cancer were released this week. The headline screamed the sensational claim: “'Game-Changing' Study Links Cellphone Radiation to Cancer”. However, what the study actually found may be far from settled.

First, let me say I have a great interest in this topic. Not only am I an amateur radio operator who uses relatively high powered RF devices on a frequent basis, I also lost a close friend (and former boss) to brain cancer. Although he was just 37 when he died, he had already spent many years using early model cell phones and other equipment in the broadcast radio industry where he, no doubt, was exposed to much higher levels of RF than the average citizen.

Do I want there to be link between RF exposure and cancer? No, absolutely not. However, do I want to find a away to prevent the cruel decline and death that my friend and his family endured? Absolutely. Let's be absolute in both cases.

Let's take a look at the study's report and dig through some of the findings.

First, the report is NOT a complete report on the study. According to its authors, it only “presents partial findings” of the study and notes that analysis of the complete data is still being conducted. The

Tuesday, April 26, 2016

Winlink on Raspberry PI

I've been wanting to find a way to check my Winlink using my Raspberry Pi. I was not too familiar with AX.25 and all of its workings, so this was an education process from the start.

I'm using a Pi 2 running Raspbian Jessie, along with Direwolf, a Singalink and a Baofeng UV-5R. I maintain a 1200 baud packet RMS Gateway at our our local Office of Emergency Management.  Here's the steps I took, with great thanks to Andrew's Memory Blog who was doing something similar.
  1. Connect the radio to the Pi. In my case, I had a spare Signalink which I used. I built an audio cord from half of an old Baofeng earpiece and some Cat5 cable.
  2. Update your Pi with: 'sudo apt-get update' and then 'sudo apt-get upgrade' 
  3. Download and build Direwolf. Instructions for doing so on a Pi are here. These instructions are for an iGate, but the basics of getting direwolf on the Pi come straight from the software author and as great. 
  4. Configure Direwolf with your callsign and sound card. The file to edit is direwolf.conf, found in the installation directory. VERY IMPORTANT: This tripped me up even AFTER reading this. Be sure to avoid the  “# ADEVICE – plughw:1,0” line. It looks a lot like the correct “ADEVICE  plughw:1,0” line, but takes input from stdin instead of the sound card. Uncomment the one WITHOUT the dash in the middle of it. 
  5. Install AX25. Next: sudo apt-get install ax25-tools ax25-apps libax25-dev libncurses5-dev
  6. Edit /etc/ax25/axports and set one line to:  radio  mycall 1200 255 2 VHF
  7. Make sure all the other lines in axports have # in front of them (it doesn’t like blank lines).
  8. Run “direwolf -p” to get the KISS port. It will show up as something like /dev/pts/2. Once it’s running, move to another terminal window

Wednesday, April 13, 2016

Rasp Pi crash causes outage

Well, I had a Raspberry Pi crash on me earlier today. It happened to be the one serving as a data bridge for my new weather station. This $35 computer's single purpose is to take data from the station and upload it to the Internet. Unfortunately, the boot partition on the system's SD card suddenly corrupted on me. It took a little work, but I was able to install a new OS and we are back in business!

I am now, once again, uploading data to several weather sites including: Weather Underground (KTXHENDE9), WeatherCloud (cool new site), WeatherBug and the Citizens' Weather Program (via Amateur Radio). There is also this cool display.

The whole process has been a fun experience, especially learning the ins and outs of weewx, the program that handles the weather data. It's a native Linux program and runs very well, even on a relatively old RasPi B+.

For those interested, you can view the raw APRS packets sent here as well as a nice table of weather data here.

Monday, April 11, 2016

New Weather Station Online

After a couple of failed starts, I've finally got a new weather station up and running. The station itself is an AcuRite 2064 with a 5-in-1 Sensor Combo, located just outside my office window.

I run Linux on my office computer and don't keep it on all the time, so I decided I wanted a dedicated system to maintain the station data. So, I spent some time trying to get an older Raspberry Pi computer up and running with weewx to accept the data and upload it to the internet. Finally got it working and the data is now uploading to (via APRS-IS) as well as WeatherUnderground.

Coincidentally, we've had some storms and rain come through today, it's already getting a work out!

Here's a link to the Weather Underground site and a link to the APRS site.

Saturday, May 2, 2015

The VOA Radiogram

Map of "Media Freedom" received
via Fldigi during the VOA Radiogram
When I was the GM of the local FM radio station, I would give presentations about the station. I told people about chasing the news and taking picture with my phone which always produced at least a couple strange looks. "You take pictures?" someone would say.  I would always joke, "Sure, doesn't your radio display pictures? You might need to get a new radio!"

Nowadays, the truth is, you don't need a new radio, just a computer (or Android tablet or phone) and you CAN receive pictures with your radio. And while fellow hams may protest that this is nothing new (and they're right) what is new is seriousness with which the U.S. government is taking it.

Photo for a story on "eRadiators" received 
via Fldigi during the VOA Radiogram
The Voice of America (VOA) broadcasts hundreds of programs in dozens of languages around the world on shortwave frequencies. And up until fairly recently, it's all been audio, such as music and voice. But now, each week, the VOA is sending what they call a "Radiogram." Sent in a digital format (MFSK32, to be exact) the text-based radiogram includes 30 minutes of news and information. It also usually includes one or two pictures.

Anyone with a $10 SDR dongle (made in China by the millions), a computer, tablet or smartphone, and a free piece of software called Fldigi, can receive the VOA's Radiogram as well as the accompanying pictures.

The government is excited about this "new" project because it allows the VOA to send news, information and even graphics or photos to anywhere on the planet, especially places where the internet is severely censored or even blocked by oppressive regimes. What's more, the text or photos can be printed and distributed to others who might not have access to the broadcast, but less a "free press."

VOA Radiogram Logo
I recently received one of the VOA's Radiograms, including the photos. The lead story discussed a recent report detailing the state of the media in countries around the globe and graded each nation on the amount of "freedom" it allows its media. Here's the weekly VOA Radiogram schedule. I've included a couple of the pictures I received.

Friday, May 30, 2014

Example JT-65 QSO

I've really come to enjoy JT65 and the slooooow QSOs is allows. I'm able to work some great DX with a very modest station while working on other things on my computer. NICE! I recorded a quick video of a recent QSO with an Italian station.