Tag Archives: APRS

Ohio Section Journal – The Technical Coordinator – August 2016 edition

One of the responsibilities of the Technical Coordinator in the Ohio Section is to submit something for the Section Journal. The Section Journal covers Amateur Radio related things happening in and around the ARRL Ohio Section. It is published by the Section Manager Scott – N8SY and articles are submitted by cabinet members.

Once my article is published in the Journal, I will also make it available on my site with a link to the published edition.

You can receive the Journal and other Ohio Section news by joining the mailing list Scott has setup. You do not need to be a member of the ARRL, Ohio Section, or even a ham to join the mailing list. Please sign up!

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Now without further ado…


Read the full edition at: http://n8sy2.blogspot.com/2016/08/august-edition-of-ohio-section-journal.html

THE TECHNICAL COORDINATOR
Jeff Kopcak – TC
k8jtk@arrl.net

DSCF5081 K8JTKHey Gang,

As I’m beginning this month’s article some nasty storms just ripped through Cleveland on the 11th. There were branches, trees, wires, power lines down, and road closures on the west side due to those hazards, including my QTH of Westlake. Luckily I’ve heard of no injuries. If you’re not part of the NWS Skywarn program, please consider joining as a spotter. Skywarn is a volunteer program that helps the local National Weather Service office know what’s happening on the ground and assists in warning people about dangerous weather conditions. Training typically happens in the early spring for spotters. Check with your local club or Skywarn organization.

The Republican Nation Convention went off without major incident in Cleveland. I was working from home and had the scanner on most of that week. Three major trunked radio systems were utilized: MARCS, the new MARCS-IP (Multi-Agency Radio Communications System), and GCRCN (Greater Cleveland Radio Communications Network). If you didn’t set a wildcard or use UniTrunker to watch those systems, you probably missed a lot of the event communications. There were about 12 primary talk groups on GCRCN where most of the action took place. These were previously unidentified so they were not in any lists or databases that use Radio Reference. A wildcard stops on any talk group whereas programming specific talk groups into the scanner will only stop on transmissions for those talk groups. The “old” MARCS system was shut down immediately following the convention as it was kept online largely for backup. It has been replaced by the MARCS-IP system.

This month we learned the sad news of Hara Arena’s closing. No more Hamvention at Hara Arena after 52 years. The Dayton Amateur Radio Association put into action their contingency plans. It was announced that Hamvention will still be in the Dayton area. The new location is The Greene County Fair and Expo Center located in Xenia, Ohio. Michael Kalter and Ron Cramer talked about the new location on Ham Nation for about 30 minutes in episode 259. Couple of links worth visiting:

-Why we are saddened by the loss of the Hara Arena: http://ad8bc.com/bc/?p=601
-Hamvention Announces Venue for 2017: http://hamvention.org/hamvention-announces-venue-for-2017/
-Ham Nation episode 259: https://twit.tv/shows/ham-nation/episodes/259, or YouTube link: https://www.youtube.com/watch?v=g_OaKmllEDY

One of our Technical Specialists, David KD8TWG, has been involved with setting up a DMR repeater in Cleveland. The frequency is 442.0875 (+5 MHz standard offset) using Color Code 1. The repeater is connected to the K4USD cBridge (http://www.k4usd.org/). On that website is a listing of the “standard DMR Logo configuration” for repeaters connected to the bridge. Right now, your code plug should follow the layout listed on the site. A cBridge is a feature that allows interconnecting of repeaters over the Internet and a Color Code is equivalent to a PL tone or DCS on analog repeaters.

When I picked up my DMR radio at Dayton, I found a code plug that had repeaters in Dayton and Columbus for the drive home. It was a nice opportunity to quickly get on the air with DMR but I kept threating myself to write my own. With the installation of the repeater in Cleveland, I took the opportunity to do just that. What is a “code plug?” Some history I found online notes the origins came from wire plugs, later jumpers, which were plugged into the radio to enable certain options or features. Since everything is now processor based, the term continues to stick with the radio world and is a fancy word for ‘radio configuration.’ It contains transmit/receive frequencies, tone selections, timeout values, IDs, configuration settings, etc. I used the one I found in Dayton as a reference. Tytera MD-380 There is also a sample one on K4USD’s site for my radio. I compared the two and designed mine the way I thought worked best. Just because someone designed a code plug one way doesn’t mean you can’t modify or do it differently. It’s analogous to one ham’s memory channels are not the same as another. In the end, it took about 3 hours to make mine! Keep in mind that was a lot of learning and comparing, in addition I programmed all 65 possible talk groups so I don’t have to add them in later. From discussions on the air indications are it took others a few hours as well. But my code plug works! I couldn’t be happier. Well OK I could, apparently I’m just far enough away that my 5 watts doesn’t quite make the trip. I took the radio to work and tested it from there.

I am writing an introductory series for the Wood County Amateur Radio Club on getting started in digital modes. The first few articles were for those who have never worked digital and want to upgrade their station. Remaining articles will focus on a specific mode. I’ve completed 3 so far (starting in February): an introduction, station setup, and working JT65/9. Published versions can be found at the club’s website WSJT-X Conversation in the CQ Chatter newsletter: http://wcarc.bgsu.edu/. As I point out in the second article, Technician class licensees can still participate. All of these sound card digital modes can be operated over FM simplex or even a net on a repeater using an HT! There are clear downsides like not being able to transmit as far as an HF station and occupying the full 10 to 15 kHz FM, even though the bandwidth of the audio generated by the computer is less. Yes, this defeats the purpose of narrow bandwidth modes. Someone wanting to learn and experiment with these modes may get bitten by the bug and lead to a license upgrade. That’s how I did it. I plan to write an article every 2-3 months.

My dad and I had the opportunity to join the Toledo Mobile Radio Association (TMRA) on August 10. They had Chris Wilson N0CSW, National Sales Manager for Yaesu talk about their System Fusion. Chris did make it clear that the company was paying for travel so there would be some ‘sales pitches.’ The presentation was short but the program ended up being driven by the audience with a lengthy question and answer session. Some things I learned: the DR-2X Yaesu DR-2Xrepeater announced at Dayton is not going to be a replacement for the DR-1X, though they may have improved on some shortcomings. The 2X is more of a full featured repeater. It will have the ability to operate dual receive and dual transmit (but not at the same time) creating two repeaters from one unit. They are including voice messaging (like club meeting announcements). Mailboxes were users can record messages for others. This reminds me of the mailboxes repeaters used to have when autopatches were more prevalent. The 2X can monitor a separate control channel for commands. This repeater will not support WiresX but will have “MSRL” (Multi-Site Repeater Linking) via an add-on Ethernet port. Their linking technology will allow the repeater to be linked over any IP based network, including mesh. This brought to mind an interesting use-case where multiple low profile/portable repeaters could be linked at sites with mesh such as air ports, hospitals, and Red Cross shelters. This would create a linked repeater system where not as many users would have to setup cross-banding or run to the other end of a hospital to reach a radio. In contrast, something similar can be done using the AllStar Linking system. At the meeting there was alot of: “I would like this feature/I don’t like this feature in the radio,” “we’re having this problem setting up the repeater to do X” kind of Q&A. My take away from that, their plan is to add features to radios by firmware update and not always release new radios.

In addition to all the work David KD8TWG has been doing to get DMR up and running in Cleveland, he’s been helping repair and upgrade analog repeaters, and setting up APRS IGates around town. He will be giving a presentation on APRS at the Lake Erie Amateur Radio Association’s club meeting on August 30th. Dinner starts at 6:30pm with the meeting at 7:30, don’t need to have dinner to attend the presentation. Haven’t seen an official announcement on location yet but it’s expected to be at the Play Arcade in Mayfield Hts (5900 Mayfield Rd, Mayfield Heights, OH). Check the LEARA website for updates and for dinner reservations: http://www.leara.org/.

Raspberry Pi 3I will be giving my introductory Raspberry Pi presentation at the Cuyahoga Amateur Radio Society meeting, September 13 at 7:30pm. It will be updated as there is new hardware and innovations available. Their meeting location is the Busch Funeral Home, 7501 Ridge Rd, Parma, Ohio. More: http://www.2cars.org/.

Thanks for reading and 73… de Jeff – K8JTK

APRS RX IGate with RTL-SDR and Raspberry Pi

For sometime I wanted to experiment with an APRS IGate. Coverage was spotty at best in my area. There is an IGate in my city but it doesn’t receive so well. Recently there have been more IGates blanketing the area.

APRS stands for Automatic Packet Reporting System and has been developed since the late 1980s by Bob Bruninga – WB4APR. It’s a digital communication mode amateur radio operators use to primarily broadcast location information, though this wasn’t the intended use. It handles text messages, alerts, announcements, bulletins, and information of interest like weather station reports. APRS operates typically on a single frequency.  A system of relay stations and digipeaters repeat messages over a wide area. APRS Internet System (APRS-IS) are Internet connected receivers (IGates).

Any ham can add an icon or information to the APRS map.  The information is available on the Internet or to users on the local RF network.  Data is automatically tracked over time. APRS is frequently used to track mobile stations in a public service event or volunteers in a search and rescue event to visualize locations and track progress.

This project will utilize the Raspberry Pi and RTL-SDR dongle. The Raspberry Pi is a credit-card sized micro-computer intended for teaching computer science to students but became popular with the makers. RTL-SDR dongles are DVB-T (European standard) TV tuner dongles. It was found the signal data could be accessed directly which allowed them to be converted into wide band software defined radio receivers. The Pi costs about $35 and RTL-SDR about $20.

Since the RTL-SDR dongles are meant to receive high power wide bandwidth TV signals, they are not as a sensitive or frequency stable as a ham radio or scanner. Receiver performance will be a little less than an equivalent radio performing the same task but depends on the usual variables: amount of APRS activity, antenna height, antenna gain, propagation, etc, etc. With my antenna about 15 feet high, I get about 5+ miles of coverage. With band openings I’ve heard stations on the opposite side of town and across Lake Erie into Canada.

Even though this IGate will be non-transmitting (cannot relay packets from the Internet), packets are forwarded to APRS-IS. The higher profile – higher power Digitpeaters in the area will relay packets received by your IGate to the local RF network.

Assumptions

This guide is step-by-step in nature, meant for beginners, with brief explanations of the steps. It will help to have an understanding of Linux commands and scripting. Capitalization is important in Linux!

My setup is on my home LAN. The IGate could be installed at a remote site using a shared Internet connection. Be aware that firewalls that might block connection to the APRS-IS network on a shared connection. You may want to request or have port 22 open on your router for SSH to establish a remote connection.

If all wired options fall through, look for a cellular hotspot device such as a MiFi to install along with the Pi. Use the built in WiFi on the Pi 3 or approved WiFi dongles for earlier Pi devices. Associate the MiFi with your Pi (turning on WPA2 so no one else piggybacks on your connection). Test the setup before installing it. Don’t find out after leaving the site that the MiFi times out after a few hours.

Program versions

Applications and versions used in this writeup:

  • Windows 10 64 bit
  • Raspbian Jessie 2016-05-27
  • Win32 Disk Imager 0.9.5
  • PuTTY 0.67
  • SDR Sharp 1.0.0.1444
  • RTL-SDR 0.5.3
  • Multimon-NG ?
  • Pymultimonaprs 1.3.0

Parts list

Listed below are all the parts needed to get this project working. It is noted when items can be left out or substituted.

That’s all the parts needed for this project. Check out the AdaFruit Raspberry Pi page for other hardware that might be useful, like the USB to PS/2 adapter for example. Many of these parts are included in the Raspberry Pi Starter Pack.

Dongle Bits: Projects

This article appeared in the The Lake Erie Amateur Radio Association newsletter The Spirit of ’76 and ’88 June 2014 edition and The Wood County Amateur Radio Club newsletter CQ Chatter July 2014 edition.

Read the rest of the series in the Dongle Bits articles category.


We’re going to take a look at projects others have done with micro-computers and controllers. Many of these will be Amateur Radio related but I will highlight some getting started projects that show setup or basic programming. Since many Hams are into computers and programming, I will highlight some networking and server related uses. Finally, some of the more some crazy and unique setups I’ve come across.

First thing to note: if you receive this newsletter in printed form, you’ll want to go to the club’s website or get it in electronic form to view these links. Links will be to videos or instructions posted online. Any YouTube videos will start at the beginning of the segment.

Getting started tutorials

Ham Radio

I was informed the University of Akron Amateur Radio Club (W8UPD) was planning on using the Raspberry Pi for their second High Altitude Balloon launch on April 8, 2014. Though no reason was given, it was scrapped for the Beaglebone Black board. They configured it to send back Slow-scan TV images overlaid with telemetry information. Unfortunately, the launch was a failure due to high winds and “poorly placed trees.” Upon launch, the payload got snagged and caught in a tree.

I heard from John – N8MDP who setup his Raspberry Pi as a D-STAR hotspot as well. His setup works with the “X-Reflector” system. There are multiple D-STAR reflector systems that co-exist together on the network. His instructions are detailed and the setup is different than mine because different software is needed to access these alternative reflector systems. John installed a webserver on his Pi to control it from the Internet.

Raspberry Pi

Arduino

Networking and server

One of the first projects I saw was how to use the Raspberry Pi as a Home theater PC. This allows you to watch videos, listen to audio, or display photos accessible via the network on a TV.

A Pi can be turned into a home or portable access device used in conferences, competitions, demonstrations, or school project. Some examples are a router, network attached storage (NAS) device, web server, or secure virtual private network (VPN) server. The VPN server uses OpenVPN, an excellent encryption package that offers trust no one (TNO) encryption since you generate the encryption keys.

A useful project is the Raspberry Pi IP address IDer which speaks the IP address if you are operating headless and need to connect to it.

Cool and unique

Want to relive the 8-bit gaming days of the Commodore 64? There is a project called Commodore Pi to create a native Commodore 64 emulator and operating system for the Raspberry Pi.

Build a coffee table gaming rig.

Turn a Raspberry Pi into an FM transmitter.

If you like cheap phones, for $160 you can create your own Raspberry Pi smartphone.

Want to give your dog a treat via email? The Judd Treat Machine will do just that! Send an email to the dog’s email address, it dispenses the treat, snaps a picture, and replies with the picture attached.

The University of Southampton in England created the Raspberry Pi Supercomputer using 64 Raspberry Pi computers. They use a “message passing” system to distribute processing across all 64 devices. His son also helped out by building the rack to hold them out of… Legos!

Raspberry Pi and Lego Supercomputer

Other places for projects and news

Raspberry Pi forums.
Arduino forums.
Slashdot: (Pi) (Arduino).
Lifehacker: (Pi) (Arduino).
Reddit: (Pi) (Arduino).
Podcasts.
Search the Internet!

Next time, we’re going to move on to another type of dongle: the $20 software-defined radio.