Tag Archives: ADS-B

Ohio Section Journal – The Technical Coordinator – January 2023 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 Tom – WB8LCD 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 Tom 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!

If you are an ARRL member and reside in the Ohio Section, update your mailing preferences to receive Ohio Section news in your inbox. Those residing outside the Ohio section will need to use the mailing list link above.  Updating your ARRL profile will deliver news from the section where you reside (if the leadership chooses to use this method).

  • Go to www.arrl.org and click the Login button.
  • Login
  • When logged in successfully, it will say “Hello <Name>” in place of the Login button where <Name> is your name.  Click your Name.  This will take you to the “My Account” page.
  • On the left hand side, under the “Communication” heading (second from the bottom), click Opt In/Out
  • To the right of the “Opt In/Out” heading, click Edit
  • Check the box next to “Division and Section News.”  If it is already checked, you are already receiving the Ohio Section Journal.
  • Click Save
  • There should now be a green check mark next to “Division and Section News.”  You’re all set!

Now without further ado…

Read the full edition at:

Jeff Kopcak – TC

Hey gang,

I’ve traveled for work to our other facilities and taken advantage of training related travel. We were thinking I would have more travel opportunities. However, due to business need, sequestered to our homes for 2 years, and the freaking economy – it hasn’t happened. I had the opportunity to attend a work conference earlier this month and it gave me ideas to promote ham radio.

Work conferences are an opportunity to attend sessions and talks to gain skills, education, knowledge, keep current with industry trends, and network with others. If you’ve been to forums at Dayton, work conferences are 2/3/4 days of forums focused on an industry or segment. These could be: sales, information technology, manufacturing, human resources, C-Suite topics, project management, or general trends – like how work-from-home has changed and challenged work in the last 3 years. Similar to indoor vendors at Dayton, companies will sponsor booths with giveaways, swag, and maybe an opportunity to find a new job.

A number of co-workers and myself attended a conference called CodeMash in Sandusky at the Kalahari Resort (near Cedar Point if you’ve never been). This year was CodeMash 10000 (binary for 16). It was my first time at this conference. The conference is developer (programmer) focused but had tracks for information security, data, and career development. There were fun things to do including board games, laser tag, a maker space, evening events including casino night, and access to the resort’s indoor waterpark. The full conference runs four days in two halves. The first two days are called the “Pre-Compiler” consisting of two four-hour sessions per day. These are deep dive table-top exercises, discussions, and hands-on labs. Second two days are more byte-sized (see what I did there?) one-hour talks.

For work-related conferences, travel and accommodations are often paid for by the employer because these are training and educational sessions related to employment, job description, or a particular project. The employer hopes attendees return with new ideas and out-of-the-box thinking.

Depending on conference, cost can be way above beyond one’s means to attend on their own. CodeMash tries to be reasonable allowing individuals to attend at their own expense, if desired. A full 4-day ticket is between $800-$1,100 and the 2-day between $400-$550. Booking rooms through the conference at Kalahari offers discounted rates over normal nightly rates, though attendees can opt to stay at near-by hotels to be more economical. Kids have their own events called KidzMash, free with a registered adult.

Presenters for this conference are chosen by submitting abstracts to the CodeMash committee. If chosen, presenters get a free ticket to the conference as compensation for presenting. Sponsored sessions are hosted by companies sponsoring the event – these are listed as such and were on the last day. Presenters can plug their business and/or employer as their company is likely covering remaining costs. At least one presenter said they were there on their own dime as their employer “didn’t see the benefit” – and yet their lab session was standing room only.

Intro to Docker session. I’m way in the back row on the right. Twitter: @OtherDevOpsGene

I figured I wouldn’t have much time to play radio as the schedule was pretty grueling with breakfast at 7 am and sessions wrapped up around 5 pm each day – not including evening activities. In the past, I’ll bring at least one radio, a mobile radio if I’m driving and know I’ll
have extra time. Though I was driving and staying at the resort for this conference, I brought an HT, hotspot, and a couple RTL-SDR dongles because I like monitoring the Ohio MARCS-IP public service system. I was not expecting to have ham radio interaction during the conference.

First day of the conference at breakfast, this guy sits down at my table. It looks like he’s got a Yaesu Fusion radio with a whip antenna. I asked him “ham radio?” He says “yep, you?” “Oh yeah.” Talked with Dan – AD8FY about ham activities and his experiences as a pilot. He informed me there was an unofficial UHF simplex frequency and there would be a number of hams at the conference. This did surprise me as I wasn’t expecting it but again, first time. Feeling pretty good about the conference and some connection to ham radio.

During one of the Pre-Complier sessions, learned there was a Slack instance for the conference. Slack is an instant messaging platform available on just about every device. Slack started out as a professional communications platform (like Microsoft Teams or Google Chat) but became accepted as a community platform for things such as this conference. In addition to messaging, Slack can do VoIP calls, video calls, file sharing, and text messaging in channels (like a conference room) or to individual users. A feature I like is persistent messaging allowing people to see prior messages after joining. For example, I joined the Slack instance on the second day of the conference but I was able to see messages from the previous day. This is different from other chat services which only show messages sent after one has joined the channel.

Guy – KE8VIY SDR live demo, receiving ADS-B broadcasts

CodeMash’s Slack had many different channels: events taking place during the conference, discussions around hotel reservations, and water park. Announcements – changes, cancellations, updates, and general information. General discussions. Major cities had channels for attendees from those areas to network, such as #cleveland. Pre-Complier portion of the conference had a channel for presenters to post their slide-decks and labs. Slides channel for presenters from the second-half of the conference. Hobby channels included beer, wine, music jam sessions, and ham radio. Oh, really?

KE8VIY asked to have a #ham-radio Slack channel. Ten people conversed about radio and when they were monitoring the simplex frequency. Call signs seen: WX8TOM, WX8NRD, KD8NCF, KE8VIY, and myself. I found out later KD8NCF gave a presentation at the conference on Real-Time Web Applications.

Thursday afternoon, while heading to an afternoon one-hour session, saw this guy (that’s his name too) outside one of the conference rooms pointing an antenna around. Figured he was doing Wi-Fi hunting or something. He too had a HT with him. This was Guy – KE8VIY. He was preparing for his presentation later that afternoon using software-defined radio to decode ADS-B (aircraft broadcasts). Though he was unsure there would be any aircraft to track as all flights were grounded earlier due to a possible cyber-attack.

I told him I would be attending his presentation. Knowing a ham was doing this session helped swing my decision in his favor because there was another equally interesting session on another hobby of mine, homelabbing. That decision paid off because not only was Guy’s presentation excellent, it got the wheels turning on more ways to promote ham radio. “Tracking Aircraft with Redis & Software-Defined Radio” (GitHub repo) was the presentation.

I’ve never used Redis. Reading up on it, the technology works mostly in-memory as a structured data store, often as a caching service (session, page, message queue) or key-value database. According to Wikipedia, Twitter uses Redis and Redis is offered by the big-name cloud providers AWS, Azure, and Alibaba.

Guy’s slides were professionally done and visually appealing. Coupled with the slides, his personality, humor, and live demos, (if I didn’t know anything about it) he made ham radio seem fun and interesting. He stated he is a new ham and excited about what he’s been able to do processing radio signals. The audience was highly engaged asking questions and feedback was positive from hams that saw the presentation.

Most maybe thinking: you don’t need a license to receive ADS-B, how is this related to ham radio? That’s the tie-in. He worked in history of digital signals, formats, and all the things rooted in ham radio: Morse Code, RTTY, and APRS. Then demonstrated how he used a modern technology platform and a radio to capture and process digital signals, all at a developer conference. Well done!

There are a lot of slides in his deck. Due to the one-hour time limit, the first 30 slides and some diagrams were covered. He utilized Dump1090 for turning signals into raw data. Then used Redis (also his employer) to process, store, and make data available to consumers.

These things fit my thinking of how ham radio should be promoted. Promoting to kids is admirable and exposing them to activities early in life is a great way to maybe hook them later in life. Credit to my parents because ham radio was one of those activities and it happened to stick. Though, I seem to be the exception rather than the norm. There are other things my parents had me join in school that didn’t stick and I really don’t miss those activities. A way kids get their license is part of a school program or curriculum. How many carry on and renew their license after 10 years is up? Retention needs work. Chances are better if family members are active and involved.

Guy – KE8VIY SDR live demo, ADS-B broadcasts shown on a map

I have been a huge fan of initiatives by the ARRL and clubs to use Makerspaces as a way to breathe new life into the hobby. Makers are like-minded people whom like to learn, create, and invent as does the experimentation side of ham radio.

Gainfully employed individuals would be my next target audience – you know, if I were on a committee. Somewhere in the neighborhood of 25-45-year-olds – those looking to keep themselves busy – whether they’re single, don’t yet have a family, or had their kids graduate college. These individuals have disposable income for equipment and time that can be devoted to learning and operating.

A conference like CodeMash is a near perfect match for promoting ham radio to technically minded individuals, including kids. Not having any statistical data, I would say the median age was probably mid-30’s, early 40’s. Obviously, there were younger and older individuals. With few exceptions from my interactions, participants were gainfully employed as their companies were picking up the tab for them to attend the conference. There were an estimated 1,400 attendees at this year’s conference. (attendance was still down from previous years, close to half). That’s 1,400 technical people, a great audience to promote ham radio.

Does a conference you attend offer a communications platform like Slack? Ask for a ham radio group to be created. Post a simplex frequency for general chit-chat. Maybe organize a meetup during meal time or after events that day to network with other hams. Maybe non-licensed people will drop into the channel or drop in at the meetup. Maybe they’ll get bit by the bug and be looking for an Elmer.

Think about current job responsibilities, technologies or services your company provides. Guy, in the spirit of ham radio, took an existing technology, re-purposed it to receive signals and turn the data into events, maps, and an API (application programming interface, used for integrating with other applications) from aircraft broadcasts.

How can a technology you’re created, are familiar with, maintain, or work with become an interesting presentation that ties in ham radio? Figure that out and maybe you’ll get a free ticket to a conference with the employer picking up the tab for travel expenses!

I brainstormed examples using technologies seen at the conference to do radio related things:

  • Real-time data processors like Kafka for mapping propagation
  • Networking skills and technology to improve resiliency and security of mesh networks
  • Table-top-exercise to recover from a disaster. Assume all existing connection and authentication methods are non-existent.
  • Receive signal data from a distributed radio network
  • APIs to administer digital systems with many connections
  • Automate test-cases and frequent software updates with GitHub pipelines
  • Incident response to handle compromises of repositories or stolen credentials
  • Docker & Kubernettes to build simple, easily deployable applications
  • Can the “cloud” fit the general directive of not relying on other technology? How to handle and recover from outages?
  • Designing web apps to replace multi-platform applications
  • Write the next white-paper
  • Create technical documentation standards

Development work isn’t part of my daily responsibilities since I changed jobs a number of years ago. Initially wasn’t too sure about the conference. In reality, I learned a lot about technologies I hadn’t yet explored on my own. Ham radio connections made it a much better experience and hope to attend next year. Let me know if you’ve done something to promote ham radio in a similar conference-type setting to like-minded (non-ham) individuals or used modern technology platforms to improve and better ham radio.

Thanks for reading and 73… de Jeff – K8JTK

NOTE: an article written by Bob – K8MD on a portable operation during a work trip was included in the printed edition. That is available by the full edition links at the top of this post.

Dongle Bits: ADSB Radar and $60 Police Scanner

This article appeared in the The Lake Erie Amateur Radio Association newsletter The Spirit of ’76 and ’88 February 2015 edition and The Wood County Amateur Radio Club newsletter CQ Chatter March 2015 edition.

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

The holidays were a busy time at the K8JTK laboratories with a couple RTL-SDR projects. The RTL-SDR is the European TV tuner dongle that was turned into a software defined radio receiver.

Thanksgiving is one of the busiest travel seasons and I wanted to decode ADS-B data to see how many aircraft were flying around. ADS-B stands for Automatic Dependent Surveillance – Broadcast allowing aircraft to be tracked by ground stations and provide situational awareness to nearby aircraft. This is part of the FAA’s NextGen project and mandated by agencies across the globe.

I saw this project in the January 2014 edition of QST written by Robert – W9RAN. He covered building a Collinear Array for the ADS-B frequency of 1090 MHz. I used one of my ham antennas. The RF signal received by the dongle is turned into data packets by a program called ADSB# (included in the SDR# download). VirtualRadar receives those packets, decodes the data, and plots aircraft on Google Maps. This setup can work with a Raspberry Pi and I hope to try this in the future.

Thanksgiving travel in Cleveland, Ohio.

Over the Thanksgiving holiday, I saw 25 aircraft flying around Cleveland on average. I think the most I saw was 48 at once. Not all aircraft have full ADS-B implementations. For example: I would see a call sign but no position data. My receive range (depending on aircraft altitude) was east of Toledo to the PA border and south to Canton. Visit my write-up on this project: ADS-B Decoding with ADSBSharp and VirtualRadar Server.

The second project is a little more complicated but it helped me understand how trunked radio systems work. With the FCC narrowbanding mandate in certain RF spectrum, many public service agencies have decided to “go digital.” In my area the MARCS-IP system and the Greater Cleveland Radio Communications Network are most popular. Both are P25 trunked digital systems. P25 is a specification for voice and data transmission. Trunked radio systems operate by having a radio send data to the control channel requesting communication on a talkgroup. The control channel directs all users of that talkgroup to a specified channel. When the user is done transmitting, all radios switch back to monitoring the control channel for further instructions. This is done seamlessly and allows many users (agencies) to use a small set of radio frequencies. Users only hear the conversations on their assigned talkgroup and not other users on the same system.

P25 trunked decoding with a single voice decoder.

Scanners that receive these systems run $500 and go up from there. Using two RTL-SDR dongles and software (mostly free), I’ve been able to receive P25 trunked systems for about $65. One dongle monitors only the control channel and other dongle(s) jump frequencies to receive the digital voice modulation with a program decoding the audio. I can have as many voice receivers as I want whereas a scanner cannot be expanded. Most I’ve heard of is eight. There are some drawbacks like portability. Find out my experiences in my P25 Trunked Tracking post.

Fresh Baked Pi

Raspberry Pi foundation released new models over the last couple months. The biggest news coming at the beginning of February: the Raspberry Pi 2. This model comes with a quad-core CPU and 1GB RAM offering a six times speed improvement, still at $35. Initial reports are it is a lot faster!

Raspberry Pi 2

Along with the new Pi2 came a new version of the Raspbian operating system with optimizations and a new look. In the near future, Microsoft will be releasing a version of Windows 10 Embedded for the Raspberry Pi 2 FREE OF CHARGE! (see the Raspberry Pi 2 link above.)

That’s A Wrap

A goal behind this series has been to expose many hams to newer technologies and younger people to ham radio. These technologies are getting young people interested in experimenting, programming, and even Ham Radio. On podcasts I watch, I’ve heard “I want to get my Ham Radio license” by 20 and 30 year olds like I’ve never heard before. These are young people interested in experimenting, making things, building things, and hacking things — all of which are the foundation of Amateur Radio. Making has evolved into writing software, sending a chip a set of commands and analyzing what is returned, or analyzing packets. Then figuring out “what can I do with this?”

I saw a great technology round-table over the holidays and they talked about getting kids into technology. Many of the methods apply to Ham Radio. As a builder, you build something and presume what will happen. Then something different happens and now you have a mystery to solve. “Why did X happen and not Y?” A new theory develops and sucks you in. This is exactly how the Raspberry Pi, RTL-SDR, and every project surrounding them came to be. It is my opinion that we, as the Amateur Radio community, need to encourage, capitalize, and focus efforts on younger makers and hackers to get them licensed.

As this is my last planned article, I would like to take time and thank the newsletter editors for thinking this series was worth publishing and recreating all the links I included. Thank you to those who told others about this series. I got a ton of feedback and couldn’t be happier that others have found this interesting and sparked them to start experimenting. Most of all, thank you for reading.

Dongle Bits: Settings, Programs, & Apps for Software Defined Radio

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

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

Last time on Dongle Bits, I talked about the $20 European TV tuner dongle that was hacked allowing direct access to the signal data. The result is a cheap wideband receiver for your computer. We’re going to take a look at key settings you should know about when using these devices. Then look at some software and projects that transform these into systems that would have cost hundreds or thousands of dollars!

PPM and Settings

An important thing to know about these dongles: they are cheaply made and not tested for accuracy. They are designed to receive DVB-T signals at a bandwidth of 6 – 8 MHz where a few KHz error doesn’t matter. This is obviously not true when you’re dealing with FM signals that are 16 KHz wide or digital at 12.5 where a few KHz will put you on a completely different frequency or channel.

PPM stands for parts per million and is the difference in received frequency vs. frequency shown. To visualize this, use SDRSharp to receive a known FM signal. The center frequency shown will be different from the signal on the scope. Typical PPM offset is anywhere from 45 – 65 and will be in the programs settings. The dongle will drift another 2 – 5 PPM over the next 20 – 45 minutes as it warms up. Gain is obviously another setting that will help you receive signals. The RTL AGC setting works but will err on the side of too much gain. Manually, using more than 32.8 dB will overload and produce duplicate signal spikes. The Correct IQ setting will get rid of phantom spikes at lower gain settings.

PPM at 0
Dongle with no frequency correction. The actual 162.550 frequency is just to the left of the displayed frequency. 162.550 is one of the NOAA Weather Radio frequencies.
RTL-SDR Settings (PPM corrected)
Shows the gain and PPM frequency correction of 55 for the dongle I’m using.
PPM Corrected
Shows 162.550 centered with frequency correction applied.

The crystals on the RTL-SDR dongle can be replaced with higher accuracy temperature controlled crystals (TCXO) that have a variance of 1 ppm! These crystals are $10 but you have to wait for them to ship from China. Pre-modified dongles are available but you will pay three times the price for the dongle.


PCs aren’t the only place these SDRs can be used. They can be plugged into an Android device too. You will need a USB OTG cable (on-the-go) and Android 3.1 or later. Search Amazon or EBay for “USB OTG.” OTG is a standard for plugging in USB keyboards, mice, and thumb drives into mobile devices. Running external USB devices off the internal battery will drain it much faster. A powered USB hub would off-load the dongle power consumption. Apps include SDR Touch (wideband receiver program), ADSB Receiver, and SDRWeather for monitoring NOAA weather alerts on your device.

This is the RTL-SDR running on my Android Nexus 7 tablet with SDR Touch receiving the 146.880 repeater in Lakewood, Ohio. It is connected with a USB OTG cable to the RTL-SDR dongle, then to an MCX to SMA, and then SMA to PL259 adapter.
This is a screenshot of the above setup with SDR Touch.

What can I do with this thing?

The definitive source on all things RTL-SDR is at the appropriately named www.rtl-sdr.com website. This site has it all. They regularly post software, updates, projects, and new developments. There is something new just about every week.

Some features of RTL-STR.com are The Big List Of RTL-SDR Supported Software. This is the list of software packages that support RTL-SDR on all platforms. Software ranges from wideband receivers to single purpose programs. This will give you some ideas of things to try with RTL-SDR. SDRSharp was written to have plugins extend the functionality of the program. These include plugins that make SDRSharp scan frequencies, add an audio FFT, scope, level meter, or CTCSS (PL) detector.

There is an extensive list of projects and write-ups including an Amateur Radio category. Some interesting ones are receiving live NOAA satellite imagery, analyze cellular phone GSM signals, radio astronomy, signal strength heat mapping (foxhunting?), and how Brazil uses our military satellites to transmit SSTV images.

With the onset of many digital standards and narrowbanding, there are more digital signals out there you may not be able to identify by hearing them or seeing them on the waterfall. This Signal Identification Guide has known types, frequencies they may be heard on, mode, bandwidth, sample audio, and waterfall image. I find myself using the Radio Reference database search utilities to help identify signals and their owners (a premium account maybe needed for some features).

My first SDR project was to use the Raspberry Pi as a SDR remote network server. The Raspberry Pi could be placed in an attic or basement connected to an antenna and controlled by another computer.

Audio can be piped from one program into another using Virtual Audio Cable (VAC). Some time ago, during one of the digital nets on the .76 repeater in Cleveland, I used SDRSharp and VAC to receive the FLDIGI messages being passed on the net. The signal path looked like this: received RF signal (146.760) -> RTL-SDR (signal data) -> SDRSharp (audio out) -> Virtual Audio Cable -> FLDIGI (audio in) -> message decoded on screen. If I had a HackRF, I probably would have been able to transmit messages without using any “ham” gear.

The next and probably final article, I will demonstrate tracking airplanes equipped with ADS-B transmitters and listening to trunked P25 public service radio systems for under $100.