Tactical Response – Fighting Pistol

Tactical Response – Fighting Pistol

Nov. 9-10, 2017
Bastrop, TX

Instructors: James Yeager, Don Numbers, Graham Hunt

Equipment: Gen4 Glock 19 with XS Big Dot Sights. This was my first class using my fourth gen Glock 19 and I wanted to ensure it was as reliable as my older second gen Glock 19. SOE EDC Belt. If you haven’t seen or used an extremely rigid gun belt like this you’re doing yourself a disservice. Finally I used a Yeti-Tac Yeti07 Tremis edition holster for day 1, and an NSR Tactical C4 holster for day 2. These holsters are both extremely high quality kydex holsters with soft loops for attaching them to your belt. I changed holsters between days because I wanted to train with both of them. I shot the entire class from concealment. Clearing my cover garment for every draw, and reluctant re-holster. I carry concealed all day every day, I should and did train the same way.

Who: There were 26 students in my class of Fighting Pistol. We were broken up into two groups of 13. At least three of the students were Fighting Pistol Alumni which in my opinion is a testament to the class that several students thought it was worth while to come back and take the class again. In one case I believe this was the fourth or fifth time he was taking Fighting Pistol. We had a couple of paramedics taking the class, a few computer nerds, some guardsmen, and just about every other walk of life you can imagine. Before coming to Fighting Pistol I had done a number of classes with smaller schools in Indiana, and Texas. Early on though I was lucky enough to meet a former Tactical Response instructor who was willing to give my wife and I an afternoon of private lessons. He said it was important to start out with a good foundation, and he was happy to donate his time. Ever since then I’ve wanted to come to Tactical Response and take this class. It was nice that they came to me.

Class: Day 1 started with a review of the safety rules, medical and evac plan, a brief discussion of pistol grip and the mechanics of the draw. The next part was what I think the guiding principles of the entire class. Survival Principals are – Mindset, Tactics, Skills, and Gear. In that order. This class focuses very heavily on Mindset, which is uncommon and refreshing. The Instructors Don Numbers & Graham Hunt were both attentive and helpful, complimenting when appropriate and encouraging when necessary. We practiced moving and shooting with a hard focus on “make your hits!” At no point were we told we should be faster, or shoot faster. This isn’t a race, and at least once someone mentioned “You can’t miss fast enough to win a gun fight.”

Day 2 started with the single most important part of the whole class. James Yeager was present to give us a lecture on mindset, and when an Alumni tells you the lecture alone is worth the price of admission they aren’t exaggerating. One of the key takeaways I got from this lecture was avoiding going to dumb places, with dumb people is a great way to avoid needing to use any of the skills I’ve learned. “If you think you need a gun to go there… Don’t go.” I think was a quote, and it’s so very true. The shooting portion of Day 2 had a lot more focus on movement, and on shooting from cover. I hadn’t worked with cover before, and learned a lot about changing levels and sides in addition to moving further away from the cover to play better angles.

I honestly believe anyone who is even thinking about carrying a gun for self defense should take this class. The lecture alone will put you in a better position to defend yourself, or avoid ever needing to defend yourself. You can be a world class shooter and leave this class with something valuable. I can’t recommend this class highly enough and I’m looking forward to taking Fighting Pistol again in a few months as a refresher before going to Advanced Fighting Pistol.

Atomic Legion – Trauma 101

On Sunday November 12, 2017, I took a one day Trauma 101 Medical Class with Atomic Legion. This was the first time I’ve dipped my big toe into the waters of traumatic wound care, and I went in with a healthy dose of trepidation not knowing exactly what to expect. The course description provides a rather lengthy list of skills that will be covered including Crisis Mindset and Leadership mentalities. Justin Hurzeler, the instructor is an EMT-P field paramedic, officer, and trainer for a municipal EMS system in central Texas. He is a NAEMT-certified instructor in the fields of Tactical Combat Casualty Care and Pre-hospital Trauma Life Support, among other subjects, and has taught over 1000 hours of medical curricula to emergency service professionals and civilians alike.

I signed up for this class with the intent of getting a handle on how to deal with the most time sensitive of traumatic care. My family and I like to travel well off the beaten path as overland enthusiasts. It’s not uncommon for us to set up camp thirty or more miles from the nearest paved road. While my wife and I have spent many hours learning how to defend ourselves, neither of us had previously put time into learning valuable life saving skills. My goal with this class was to start myself on the path to correcting that.

As the class started we did student introductions. The majority of the students are outdoor adventure types, and similarly recognize the value in being your own first responder. One of the students explained that every couple of years he takes another class like this as a refresher.

Justin then got into the class. He started with Scene Safety, explaining that going into an unsafe scene and becoming an additional trauma victim not only doesn’t help anyone, it actively harms the other victims by taking resources away from them to also deal with your injuries. Next Justin provided us details on how to contact Emergency Services. Details were provided on how best to talk to 911, what kinds of information they need, and how best to render aid while communicating with the dispatcher. The discussion then shifted toward Legality and consent. The Texas Good Samaritan Act was mentioned. One of our students was a Criminal Defense Attorney which offered an interesting additional perspective.

Then the real fun started. Justin explained that there are several acronyms used to help with rendering trauma aid. MARCH is one of them, but in this class we focused on the much simpler CAB which hits the big three immediate care items. Circulation, Airway, and Breathing (In order of importance.) We were shown how to take a pulse from each extremity, in addition to checking pulse at the carotid artery. Knowing how to check a patient’s pulse on their leg for instance becomes important once you apply a tourniquet to their leg. To avoid causing compartment syndrome it’s important to ensure that all blood flow into the limb is stopped, otherwise that blood will pool in the limb causing significant complications. Life threatening Hemorrhage must be addressed immediately. We discussed the various commercial Tourniquets available today, their advantages and disadvantages. The SWAT-T, and CAT were the clear favorites, as they are effective and combat proven life savers. I also found the CAT to be the easiest to apply to my arm one handed. We discussed checking for a pulse after applying a tourniquet, and if blood is still flowing you apply a second, or a third, or maybe even a fourth. Justin explained that while working if he puts a Tourniquet on a thigh, he almost always puts a second one on right away as legs regularly require more than one.

While still on the topic of Circulation we talked about packing wounds in distal areas. We practiced this using a pork shoulder with the bone in, and an IV to simulate a blood vessel. This was a technique I had never performed, and found it a lot more challenging than I expected it to be. I might have to practice this more on my own the next time we have a roast prior to cooking it.

We moved on to airway management. Justin explained how snoring respiration is an indication of a partially obstructed airway. We talked about how to tilt the head back, and move the jaw forward to help relieve this, but how that also ties your hands up. He then demonstrated how to install a Nasopharyngeal Airway (NPA, or Nose Hose) by putting one in his own nose. We talked about how unconscious patients benefit from being put in “The Recovery Position” as this helps fluids to leave the mouth rather than become airway obstructions.

Finally we talked about breathing. Specifically sucking chest wounds and what we as non-paramedics can do to help. We talked about commercial chest seals, like the HyFin, or Halo but also talked about how to improvise a chest seal. Justin didn’t want to discuss using chest darts, but mentioned that if breathing becomes labored you can and should “burp” the chest seal by lifting a corner. This should release some of the pressure building up in the chest outside the lungs.

We covered so much in the 8 hour class that I couldn’t hope to capture it all. It feels like I didn’t hardly scratch the surface of immediate life saving medical skills, however Justin assures me that a large percentage of things that will lead to end of life, before higher level care can arrive were covered in great detail. I guess that’s the real lesson. What I learned in this class is enough to hopefully sustain someone’s life until a higher level medical professional can take over for me.

I’d highly recommend this class to anyone who does anything rugged outside. Whether that’s offroading in the hill country of Texas, Hiking in the mountains of Colorado, or shooting on the range on the weekends. Medical skills are useful in so many unexpected situations. One of my friends was the first to arrive at an accident on the highway. The driver had sustained a piercing wound through his upper arm and my friend was able to apply a Tourniquet to the arm preventing the driver from bleeding to death. The Paramedics said he saved the man’s life. We should all aspire to be able to save someone’s life. Who knows, it might be your own.

Atomic Legion – Pistol 101: Beyond Fundamentals

On Sunday October 15, 2017, I took a one day pistol class with Atomic Legion called Pistol 101: Beyond Fundamentals. Atomic Legion in Austin, Texas, offers several training opportunities, and Pistol 101: Beyond Fundamentals is scheduled regularly. The course description is as follows:

Focuses on refining basic fundamentals of marksmanship and introduces the student to basic movement while shooting. Enabling objectives to include draw stroke training, comprehension of the shooting cycle, reloading and malfunction clearance exercises, and demonstrated control over one’s shot tempo. The student must score 80% or better on final test to pass.

The instructor Alex Acosta is described as:

A civilian marksman living in Austin, Texas. He considers himself a perpetual student of both skill and tactics as it relates to being a responsible armed person. Much of his time is spent understanding and breaking down the mindset, mechanics, and concepts necessary for the production of performance with a firearm. His education is ongoing, having received over 300 hours of instruction from some of the nation’s elite training schools. He continues to seek out methodology on topics related to the entangled use of force, management of one’s environment, modes of de-escalation, diminished light, and advanced tool use. Alex also focuses time on emergency medicine and maintains an NAEMT – TCCC-AC (Tactical Combat Casualty Care All Combatants) certification which focuses on basic life-saving care components.

I signed up for this class with the intent of diagnosing and fixing one specific problem. If I got more out of it, that’s great, but I went in looking for only one area of improvement. The class was one five-hour day. Round count for the day was about 300 rounds. Required equipment for the class was a fighting pistol, at least three magazines, a sturdy belt, a magazine carrier, and a holster. This is pretty standard fare for a one-day 101 level class.

The day started out at the range with Alex giving a safety briefing. We established who was responsible for calling for emergency services in the event of an injury, who was responsible for the trauma kit and its application (primary and secondary), and where the keys for his truck were, which was empty with the tailgate down, in the event we needed to transport someone up to the road. We then discussed the four firearm safety rules, in addition to a small number of range rules.

Alex approaches teaching by asking the students a large number of questions like, “So what does that mean when he says don’t allow the muzzle to cross the 180 degree mark?” During drills he pays attention to what is happening down range, and he will ask you “What did you see?” or “What did you feel?” He stated early on that while the fundamentals are important individual application and understanding of them is different. He stated that his goal was to help us understand what the expected result should be and help us come up with our own systems to achieve the desired result.

We then got situated with some paper targets and did a few reps of drawing from the holster and presenting the pistol to the target. This was followed by a few reps dry firing after presenting the pistol to the target. Then it was on to live fire. We started out simply with slow fire on a large eight-inch target. Alex spent a lot of time diagnosing individual students’ grips and helping diagnose where they were having problems. A lot of focus was placed on physical indexes. For example, I index the tips of my support hand fingers into the knuckles on my dominant hand prior to closing my hands around the grip of my pistol. This physical index works for me as a guide to ensure that my grip is created the same each time I draw and present the pistol. After a few magazines, we moved on to two-inch dot targets. It was during this string of fire that Alex was able to diagnose the problem I set out to fix as my only goal for the entire class. He observed that I was flexing my dominant hand thumb at about the same moment I decided to press the trigger. This has the effect of driving the muzzle down, and explains why I could shoot small groups but always one to two inches below the target. Just calling this to my attention helped me correct it. We did a few more static drills and then started to incorporate movement with our shooting. At first it was as simple as taking steps toward the target stand, and then he would call out A or B, which designated which 2” target we were supposed to aim at and shoot. This rounded out the morning.

The afternoon started with reloading drills. Alex provided his method for reloading a semi-automatic pistol, which includes indexing your pointer finger on the top round of the magazine you’re going to insert, while simultaneously pulling the elbow of your dominant hand against your side just above your belt. Locking this elbow in makes it easier to reload when you’re moving as your hand and the mag well move around far less.
An added bonus is this rotates the magazine well toward the hand that’s holding the new magazine. Finally it puts the pistol into your field of view, while allowing you to also keep your eyes down range. To see the stability benefit of this technique you only need to try to do a reload while walking across your garage. We then moved on to some malfunction clearing drills, which brought up a brief discussion about Hick’s law, which we tabled for later.

Finally we moved on to moving while shooting: Engage a target, then running laterally across the range to address a second target, then back to the start where you would re-address your first target. We worked on transitioning between several targets where Alex talked about “dancing” as he likes to transition between targets through his hips. Then the day finished with a final exam which was a simple pass/fail with “80” as the cut off. The final exam was shot on a USPSA cardboard target. The scoring areas were rather generous. (I thought so anyway.) I won’t give away the specifics, but I will say that the final test incorporated most of what we had practiced earlier in the day, with a time component as an added stressor.

All in all I was very pleased with Pistol 101: Beyond the Fundamentals from Atomic Legion. Alex is a good instructor. He does a very good job of distilling his knowledge into small enough bites for you to pick up a little bit at a time, and add or improve your own skills. He asks a lot of questions, which can be intimidating if you’re an introvert like me, but he does it in a non-threatening way.

If you’re in the Austin area, I’d recommend this class for anyone who carries a pistol. Even if you’ve done a lot of training before with other instructors, Alex’s approach is still likely to help you improve in at least one area.

Introduction To Ham Radio (US Edition)

What Is Ham Radio:

The ARRL describes Amateur Radio as follows:
“Amateur Radio (ham radio) is a popular hobby and service that brings people, electronics and communication together. People use ham radio to talk across town, around the world, or even into space, all without the Internet or cell phones. It’s fun, social, educational, and can be a lifeline during times of need.”

You can set up a ham radio station anywhere!

On a beach…
On The Beach

…in your overland rig
In Your Rig

…or at home.
In Your Home

Although Amateur Radio operators get involved for many reasons, they all have in common a basic knowledge of radio technology and operating principles, and pass an examination for the FCC license to operate on radio frequencies known as the “Amateur Bands.” These bands are radio frequencies allocated by the Federal Communications Commission (FCC) for use by ham radio operators.”

What Are The License Classes:

In the United States there are three classes of Amateur Radio Operator Licenses (Ham)

  • Technician Class
  • General Class
  • Extra Class

Each Class license increases your privileges on the air.

Primarily the Technician Class license is for VHF/UHF communications, which work well for regional contacts. VHF (2M) and UHF (70CM) are the two most common forms of mobile ham radio communications equipment. Simplex these operate line of sight, which is to say 5-10 miles over flat level terrain.

The General Class license opens up 90% of the HF bands for you. These bands work for around-the-world communications, even with low power and modest antennas. As an example, while driving on Hwy 71 in Austin, Texas, I was able to carry on a conversation with a HAM outside Moscow, in Russia.

Finally the Extra Class license gives you the last small piece of the pie. Primarily these are edges of the bands which more closely overlap with other nations band allocations opening up more opportunities to talk to HAMs from other countries.

How Can You Get Licensed:

Ham Radio Clubs across the country offer testing sessions every month. The ARRL (Amateur Radio Relay League) provides a tool to help you locate Amateur Radio License Exams in your area. TEST FINDER

Tests cost around $15 to take. If you pass the Technician the testing site will let you take your General test in the same sitting for free. If you pass your General test, they will let you take the Extra for free in the same sitting. So with proper preparation it is possible to go from unlicensed to Extra in one day.

Once you pass a test, your license is good for 10 years, at which point you renew your license for free. You do not need to take any further tests.

Training/Study Materials:

There are books from Gordon West to help you prepare for the tests. I found Gordon West’s teaching style in his AUDIO CD Programs to be very compatible with my learning style.

You can take Practice tests for all three license classes here: QRZ.com (free registration required)
Each requires a score of greater than 70% to pass. If you are regularly scoring around 85% on practice tests, you are ready for the real thing!

FCC Law & VHF Radios (Race Radios)

I would like to thank Crom from Tacomaworld for taking the time to write this post, reproduced here with his permission.

This is just and FYI for those that may not know. And the bottom line first…

You may not use a VHF radio in the United States without a valid FCC-issued license or Amateur radio license. Use of VHF radios in Mexico is allowed during the SCORE Baja race, and subject to local regulations.

Here is an example of VHF itinerant/business band frequencies commonly used in the Baja Races. Operators of the frequencies are licensed. If you transmit on frequencies you’re not licensed for, then you are operating a pirate radio station, and are subject to fines and equipment confiscation. 🙁

I have observed a trend of individuals buying ham radios and modifying them to transmit outside the ham bands. That in of itself is not a problem. But if you key up outside the ham bands–that’s illegal, and you put yourself at risk for fines and confiscation (more on that below). Also problematic is buying business band radios and operating them on frequencies without the requisite license.

Some people think the FCC enforcement is a toothless tiger, and nothing bad will happen to them, and maybe that’s all true. But people should know that there are risks involved. And that’s why I took the time to write this, as to inform people. I don’t care what you do in the desert as long as it doesn’t hurt or interfere with other people.

Also, I think it’s incredibly foolish for people to post in a public forum the date, time, and place of a future meet and the illegal frequency they’ll be communicating on. :laugh:

If you have questions about Race radios, I have found this shop to be very helpful. PCI Race Radios. As it turns out they are the itinerant and properly licensed operator of the Weatherman frequency.

Additionally, if your not a properly licensed amateur operator please stay off the 2M & 70cm ham bands, i.e. 144-148 & 430-450 Mhz. 🙂

Finally, WB4CS a licensed amateur radio operator wrote the FCC asking a question and the answer is relevant to the topic here.

Here is what the FCC wrote:

FCC response per WB4CS said:
As you note, “The rules are clear that in order to use Part 90 or 95 spectrum, the operator must have the correct licensing and certified radios to use those services.” The debate you are referring to, therefore, comes down to “How can we get around the rules?” The answer is, “You can’t.” We will be happy to relieve you of thousands or tens of thousands of dollars and your amateur radio license if you transmit on channels you are not licensed to transmit on.

William

FCC Wireless Telecommunications Bureau

For example:

  1. CB
  2. FRS
  3. Licensed GMRS
  4. MURS
  5. Licensed Amateur radio (HAM).

Ham Radio Gear – Part 2

Here are some example mobile transceiver options. Each of these is a dual band radio (2m and 70cm). Also each of these has a detachable, or detached, control head. I’ll add a note next to each with additional features.

Kenwood, Icom, and Yaesu are regularly referred to as “The Big Three.” They are the ham radio equivalent of Ford, GM, and Chrysler. There are other brands, but if we’re focusing on high quality, reliable equipment, these are the brands that are going to receive all of my attention.

Icom

  • IC-2730a – Dual Receiver / Cross Band Repeater
  • IC-880H – D-Star Digital Mode Ready
  • IC-5100A – Dual Receiver / Cross Band Repeater / APRS capable / D-Star Digital

Kenwood

  • TM-V71A – Dual Receiver / Cross Band Repeater
  • TM-D710GA – Dual Receiver / Cross Band Repeater / APRS capable

Yaesu

  • FT-7900R – Dual Band
  • FT-8800R – Dual Receiver / Cross Band Repeater
  • FTM-100DR – Yaesu Fusion Digital / APRS Capable
  • FTM-400DR – Dual Receiver / Cross Band Repeater / APRS capable / Yaesu Fusion Digital

Digital Modes
On the topic of Digital Modes. There are currently three competing standards. (Think VHS vs Betamax) or for you youngsters (BluRay vs HD DVD)

Yaesu has developed and released a system called Fusion. It’s based on C4FM.
Icom has had a system called D-Star for the last 10 years.
Motorola Has a system referred to as DMR, or MotoTRBO.

If my Crystal Ball is tuned properly, I think Yaesu’s Fusion system is going to end up being the winning technology for most average hams. I make no promises that this is correct. However looking at how unsuccessful Icom has appeared to be with D-Star, I think it’s unlikely they’re going to win the battle.

I think the EMCOM (Emergency Communication) crowd is going to flock to MotoTRBO/DMR. In large part because many of the ARES/RACES Emergency Communications types also work with Police/Fire/Search & Rescue Teams and are carrying Motorola radios already.

I didn’t mention Motorola radios above in my list. Motorola builds some exceptionally high quality equipment. However it’s all designed for use as Business Band Radios. They work fine in the Amateur Radio Service, and it’s legal for a Ham to use them as such. However I think anyone leaning toward a Motorola, is already experienced enough that they’re not looking for any advice from me. 🙂

Ham Radio Gear – Part 1

Mobile Radio Gear: (VHF/UHF only in this segment)
Radios for Overlanding fall into two major categories. Handheld Transceivers (HTs) and Mobile Radios.

Handheld Transceivers are effectively “Walkie Talkies” and can run from as inexpensive as $35 per unit for a Baofeng UV-5R all the way up to several hundred dollars for a top of the line Yaesu/Icom/Kenwood digital HT, like this Yaesu FT2DR. HTs typically offer several power settings, with Low being ~ 0.5W, medium being 1-2W, and high being 5W. At 5W the radios tend to get hot while transmitting a lot, and the batteries don’t last long. (It’s worth noting a CB maxes out at 4W in the United States…)

Mobile Radios come in three major varieties, and then have a host of options. The three major types of mobile VHF/UHF rig are:
Single Band (usually 2M)
Dual Band (usually 2M/70CM)
Dual Band CrossBand Repeater (usually 2M/70CM)
The single band radios are exactly what they sound like. These radios operate within a single band, which usually means 2M, although they don’t have to. These usually, but not always, output between 5w on Low Power and upwards of 75W on High.

A dual band radio is virtually identical to the single band radio, except you can select between two bands. This means if you’re in a small group, and if everyone has dual band, you can select which band you want to use. The 2M band is the most popular band in the world. If you’re looking for a quiet place to talk within your caravan, you might choose as a group to move to 70CM for instance.

Finally we have CrossBand Repeaters. These are also dual band radios, but they have two receivers in them, rather than one. This means they act in many ways as if you have TWO radios at the same time in your vehicle. These include a special mode of operation though, that allow you to “connect” the 2M radio to the 70CM radio. Thus, anything received on the 70CM side will be instantly re-transmitted on the 2M side. And anything received on the 2M side, will be re-transmitted on the 70CM side. When coupled with an HT, this can allow you to use the HT on 0.5W on 70cm, but communicate with a remote station using the 50-75W 2M transmitter in your vehicle. (Ask me about “Red River Gorge” in Kentucky sometime.)

Digital Mobile Radios Another newer entry into the Mobile, and HT ham radio market is Digital radios. These all operate normal FM like the others listed, however they include some form of digital encoding. Right now there are no “standards” so each vendor has their own competing protocols. Yaesu appears to have the most widely adopted system with C4FM FDMA and their Fusion Repeaters. This is a fairly in depth discussion on its own, and I’d be happy to field questions to the best of my ability but won’t muddy the waters here.

Like everything else in life, in many ways you do get what you pay for. I personally intend to pick up a few (5?) UV-5R radios to keep in a Pelican case in the truck for dire emergencies but wouldn’t personally trust them as a primary radio. Ham radio is like a lot of hobbies. There are many different ways to participate and enjoy the hobby. I’ve hardly scratched the surface here. I, and I suspect the rest of the Hams on Overland Bound, would be happy to field any discussion on the hobby you might have.

Single Band 2M Radio
Single Band 2M Radio

Dual Band 2M/70CM Radio
Dual Band 2m/70cm Radio

Cross Band Repeater
Cross Band Repeater

Yaesu Digital Cross Band Repeater
Digital Cross Band Repeater

Ham Radio Could Save Your Life

Natural Bridge Kentucky

Natural Bridge

When my wife and I went to Natural Bridge in Kentucky back in 2007 she wrote the following diary note to go with this photo.

While hiking in the park, I noticed that the nearest Cell phone reception was 11 miles down the road from where we were.

There’s also a warning on the bulletin board near virtually every trail head: “Every year, about forty-five people fall from these cliffs. One or two usually result in death. Once contact is made with emergency personnel, it will take at least thirty minutes for someone to arrive. Many falls result in spinal injuries, so the person who comes to find you must wait for the EMTs to arrive to remove you safely – another thirty minute wait. Unpacking all the equipment, bundling you up securely, and getting you back to the emergency vehicle can take over an hour. It’s a forty-five minute drive to the nearest hospital. In other words, if you fall, it could be about three hours before you receive proper medical treatment. And that’s after you actually manage to contact someone.”

I ensured that from my car, parked in the lot I could reach the local 2M repeater in the next town over. I then turned on the cross band repeater, and set the 70CM side of the car, and my HT to match one another. This gave me an instant link to “town” and several times while hiking, I verified that I could both hear the repeater in town, and still communicate with the hams there. (all while using 0.5W) There’s nothing like eliminating the time to get to a place you can call for help.

APRS with an RTL-SDR & Xastir

Special Thanks go out to the authors of the following two blog posts without whom I would have had to have done most of this work by myself:

This post is mostly taking details from the above two sites, and merging them into a single, easy for me to find set of notes on how to get Xastir working with the RTL-SDR on a Debian/Ubuntu based Linux system. This will serve as the foundation of a future version that will be deployed on a Raspberry Pi3-B, configured with a 7″ screen, and installed in my truck for mobile APRS tracking.

Here’s a good screen capture of my Xastir map after running for about an hour.
Xastir Map

Blacklist Drivers:

cat << _EOF_ > /etc/modprobe.d/blacklist-rtlsdr.conf
blacklist dvb_usb_rtl28xxu
blacklist dvb_usb_v2
blacklist rtl_2830
blacklist rtl_2832
blacklist r820t
_EOF_

Install DVB-T dongle:

cd ~/src
sudo apt-get install git build-essential cmake libusb-1.0-0-dev
git clone git://git.osmocom.org/rtl-sdr.git
cd rtl-sdr
mkdir build
cd build
cmake ../ -DDETACH_KERNEL_DRIVER=ON -DEINSTALL_UDEV_RULES=ON
make
sudo make install
sudo ldconfig

Install MultiMon-ng Encoder/Decoder:
While your system is likely to have “multimon” in the software repo, you will need multimon-ng

cd ~/src
sudo apt-get install qt4-qmake libpulse-dev libx11-dev patch pulseaudio
git clone https://github.com/EliasOenal/multimonNG.git
cd multimonNG
mkdir build
cd build
qmake-qt4 ../multimon-ng.pro
make
sudo make install

Install RTL-SDR Kalibrate tool:

cd ~/src
sudo apt-get install libtool autoconf automake libfftw3-dev
git clone https://github.com/asdil12/kalibrate-rtl.git
cd kalibrate-rtl
./bootstrap
./configure
make
sudo make install

Run the Kalibrate tool (Take note of the PPM)
For me Channel 1 was the strongest. (In step 2, use the strongest channel)

kal -s GSM900
kal -c 1

Test APRS Reception:
The PPM value from the above step was about 50, so that’s the value I’m using

rtl_fm -f 144390000 -s 22050 -p 50 -g 42.0 - |multimon-ng -a AFSK1200 -A -t raw -

If everything is working, you should see output similar to the following:

w9zeb@aprsstation:~/$ sudo rtl_fm -f 144390000 -s 22050 -p 50 -g 42.0 - |multimon-ng -a AFSK1200 -A -t raw -
multimon-ng (C) 1996/1997 by Tom Sailer HB9JNX/AE4WA
(C) 2012-2014 by Elias Oenal
available demodulators: POCSAG512 POCSAG1200 POCSAG2400 FLEX EAS UFSK1200 CLIPFSK FMSFSK AFSK1200 AFSK2400 AFSK2400_2 AFSK2400_3 HAPN4800 FSK9600 DTMF ZVEI1 ZVEI2 ZVEI3 DZVEI PZVEI EEA EIA CCIR MORSE_CW DUMPCSV SCOPE
Enabled demodulators: AFSK1200
Found 1 device(s):
0: Generic, RTL2832U, SN: 77771111153705700

Using device 0: Generic RTL2832U
Found Rafael Micro R820T tuner
Tuner gain set to 42.10 dB.
Tuner error set to 50 ppm.
Tuned to 144643575 Hz.
Oversampling input by: 46x.
Oversampling output by: 1x.
Buffer size: 8.08ms
Exact sample rate is: 1014300.020041 Hz
Sampling at 1014300 S/s.
Output at 22050 Hz.
APRS: KF5JZT-2>S0QX8V,K5GJ*,WIDE1*,LAGRNG*,WIDE2*:`}Fl"vR/'"6!}|*A%,'s|!wnz!|3
APRS: W5ROX-3>APOT30,AUSWST*,WIDE1*,WIDE2-1:!3034.44N/09724.99W_009/000g000t079p000h70b10169T2WX
APRS: W5ROX-3>APOT30,AUSWST*,WIDE1*,LAGRNG*,WIDE2*:!3034.44N/09724.99W_009/000g000t079p000h70b10169T2WX
APRS: W5MF-7>S0PQ8Q,N5LUY-2*,LAGRNG*,WIDE2*:'{;il ;[/>"48}146.760MHz T103 -060Marty from Houston=
APRS: W5MF-7>S0PQ8Q,N5LUY-2*,AUSWST*,WIDE2*:'{;il ;[/>"48}146.760MHz T103 -060Marty from Houston=
APRS: NK5P-9>RYUQ2T,WA5GC*,WIDE1*,AUSWST*,WIDE2*:`~&xp!,k/`"6v}147.220MHz_%
APRS: KG5DWX-13>APN391,AUSWST*,WIDE2-1:@271617z3025.30N/09740.88W_000/000g000t084r000p000P000h76b10164.DsVP
APRS: KG5DWX-13>APN391,AUSWST*,LAGRNG*,WIDE2*:@271617z3025.30N/09740.88W_000/000g000t084r000p000P000h76b10164.DsVP
APRS: W5OEM-9>APRS,AUSWST*,WIDE1*:> Ver. 02SEP2006 - TCARES ARCHES System Online: www.tcares.org
APRS: KF5DMO>APTT4,AUSWST*,WIDE1*,WIDE2-1:>/TinyTrak4 Alpha

In order to feed the output from multimon-ng into xastir, you will also need the socat command:

sudo apt-get install socat

Now we’re ready to fire up the RTL-SDR, with multimon-ng. We will redirect the output to the network on localhost:14580
Which is where we’ll then point xastir to look for it’s data.

w9zeb@aprsstation:~/$ sudo rtl_fm -f 144390000 -s 22050 -p 50 -g 42.0 - |multimon-ng -a AFSK1200 -A -t raw - | sed -u -r 's/.{6}//' | socat STDIN TCP-LISTEN:14580,reuseaddr,fork

Finally we need to launch xastir, and tell it how to find our APRS data. Launch xastir, and after the intial setup click: Interface –> Interface Control –> Add –> Internet Server Then select “Activate on Startup”
Deselect “Allow Transmitting (Your RTL-SDR is only a receiver afterall)” Set the host to “Localhost” Then click OK.
Finally you will need to select your new Internet server from the list, and click Start, or just click Start All.

Here’s a “Potato Quality” photo of my Thinkpad X201i running Xastir, with a few stations plotted on the map.

Xastir-Thinkpad

There are several Weather stations in the area I can receive directly as well.
Weather Stations

If everything went well, you should start seeing stations appear on your map. Happy APRSing.

APRS with an RTL-SDR – Part 2

In part 2 of my RTL-SDR powered APRS series I’m going to discuss how I configured an IGate using aprx. The first order of business however is getting the RTL-SDR to receive, and decode APRS traffic. The software I used is called multimonNG the installation of this package is pretty straight forward.

# git clone https://github.com/EliasOenal/multimon-ng.git
# cd multimon-ng
# mkdir build
# cd build
# qmake ../multimon-ng.pro
# make
# sudo make install

Once this is complete, we can fire up rtl_fm which we built in the part 1 and by using the Unix Pipe we are going to send the output of the receiver through multimon-ng and then onto the network. The command I’m using to start the receiver is as follows:

# rtl_fm -g 80 -f 144.390M -s 22050|multimon-ng -t raw -a AFSK1200 -f alpha -A /dev/stdin| netcat -l 6666

This opens the receiver and sets the gain to 80, on the North America APRS calling frequency of 144.390mhz, with a sample rate of 22050hz. The output of the reciever is then sent into multimon-ng which uses the AFSK1200 decoder and the -A flag tells it specifically to use the APRS format. Due to some limitations in how multimon-ng works getting the output into something usable requires interacgint with /dev/stdin. If we ended the command there, the decoded APRS packets would be displayed on the terminal for you like the following entries:

lars@bmc ~ $ rtl_fm -g 80 -f 144.390M -s 22050|multimon-ng -t raw -a AFSK1200 -f alpha -A /dev/stdin
multimon-ng  (C) 1996/1997 by Tom Sailer HB9JNX/AE4WA
             (C) 2012-2014 by Elias Oenal
available demodulators: POCSAG512 POCSAG1200 POCSAG2400Found 1 device(s):
 EAS UFSK1200 CLIPFSK FMSFSK AFSK1200 AFSK2400 AFSK2400_2 AFSK2400_3 HAPN4800 FSK9600 DTMF ZVEI1 ZVEI2 ZVEI3 DZVEI PZVEI EEA EIA CCIR MORSE_CW DUMPCSV SCOPE
Enabled demodulators: AFSK1200
  0:  Generic, RTL2832U, SN: 77771111153705700

Using device 0: Generic RTL2832U
Found Rafael Micro R820T tuner
Tuner gain set to 49.60 dB.
Tuned to 144643575 Hz.
Oversampling input by: 46x.
Oversampling output by: 1x.
Buffer size: 8.08ms
Exact sample rate is: 1014300.020041 Hz
Sampling at 1014300 S/s.
Output at 22050 Hz.
APRS: W2MN-9>S0RY7V,W5OEM-12*,WD5IYT-2*,WIDE2-1:`}Nbl7'v/"77}
APRS: WD5IYT-2>APNU19:!3019.41NS09748.12W#PHG9550 APRS DIGI UIDIGI 1.9b3 Austin b1
APRS: KF5DMO>SPQU6V,WD5IYT-2*,WIDE1*,WIDE2-1:`}JWl //"5]}/TinyTrak4 Alpha

The last three lines in the above block are actual APRS packets received by the RTL-SDR, decoded by multimon-ng, and displayed on the terminal. This is fun but ultimately I want to push those messages into the APRS network. For this I need to add an IGate like aprx. Installing aprx is much like everything else we’ve done so far.

# git clone https://github.com/PhirePhly/aprx.git
# cd aprx
# ./configure
# make clean
# make
# sudo make install

Next we need to configure aprx. For this edit /etc/aprx.conf. The file is well commented, and should be pretty straight forward. In my case, I set the following fields:

  • mycall
  • myloc
  • passcode
  • server
  • filter

Then in the section I set aprx up to use a TCP socket.

<interface>
tcp-device      localhost 6666 TNC2
</interface>

From this point we need to adjust the line we used to start the receiver, as aprx is listening to a network socket, and not looking at a terminal for packets. So we go back to our initial command and pipe the output from /dev/stdin into netcat and are left with the following:

# rtl_fm -g 80 -f 144.390M -s 22050|multimon-ng -t raw -a AFSK1200 -f alpha -A /dev/stdin| netcat -l 6666

Finally we start aprx

# aprx

And if we want to see the packets as they come in we can tail the aprx-rf.log

lars@bmc ~ $ tail -f /var/log/aprx/aprx-rf.log
2014-12-11 03:59:48.152 APRSIS    R W5ROX-3>APOT30,WIDE1-1,WIDE2-1,qAR,W5ROX:!3034.44N/09724.99W_081/001g002t060p000h78b10196T2WX
2014-12-11 04:00:04.576 APRSIS    R KF5RLL-2>APRX28,TCPIP*,qAC,T2TAS:!3032.53N/09735.37WxPHG0000 Hutto,TX - TX/RX-IGate - Linux/Aprx-2.08 - Uptime 108(hrs)
2014-12-11 04:00:05.848 APRSIS    R kc5wxt>APRS,TCPIP*,qAC,THIRD:@110400z3006.00N/09718.00W_163/001g006t061r000P002h87b10202
2014-12-11 04:00:20.635 APRSIS    R KC5AFM-1>APZAFM,TCPIP*,qAC,FIRST:!3031.57NI09747.27W#Cedar Park Digi Tx-iGate
2014-12-11 04:00:23.406 APRSIS    R KC5AFM-9>APOTU0,WIDE1-1,WIDE2-1,qAR,AE5UM:!3032.07N/09749.74W>070/029/A=000966 13.6V
2014-12-11 04:00:23.624 APRSIS    R KC5AFM-9>APOTU0,WIDE1-1,WIDE2-1,qAR,KF5RLL-2:!3032.07N/09749.74W>070/029/A=000966 13.6V
2014-12-11 04:00:26.710 APRSIS    R KE5RCS-A>APJI23,TCPIP*,qAC,KE5RCS-AS:!3044.65ND09736.13W&RNG0010 1.2 Voice 1293.2000 -20 MHz
2014-12-11 04:00:26.824 APRSIS    R KE5RCS-C>APJI23,TCPIP*,qAC,KE5RCS-CS:!3044.65ND09736.13W&RNG0035 2m Voice 145.130 -0.600 MHz
2014-12-11 04:00:26.824 APRSIS    R KE5RCS-B>APJI23,TCPIP*,qAC,KE5RCS-BS:!3044.65ND09736.13W&RNG0035 440 Voice 440.575 +5.00 MHz
2014-12-11 04:00:30.812 APRSIS    R WB5FMZ-1>APRS,WIDE2-2,qAR,KC5AFM-1:@000001z3032.06N/09745.43W_110/000g000t056r000P001h93b10212/ 15171,12.1V73F45%,F=0,V053105 LOC

That’s it for now.

73!