Folks, this has been a fun and hilarious winter project. Yesterday, when I built this air cannon antenna launcher it was -4 degrees outside and this was a perfect evening project to put together. For years, me and my two ham radio buddies (WR8S Bill Shultz and WV8TG Tom Graf), have enjoyed ARRL Field Day activities and usually used a slingshot and a 3/4 ounce fishing sinker weight and an old Zebco fishing reel (with 20 pound test line) to shoot and suspend our doublet dipole antennas high into the trees. Certainly, the slingshot worked pretty much flawlessly… but… boys will be boys, and the idea of an air cannon / spud launcher / potato gun type system seemed to be a new desire. (Most people, our wives included, wouldn’t trust our 3-man team with a slingshot, let alone a potato gun! But I digress.) Actually, our local ham radio club (Monongalia Wireless Association) had a version of a potato gun antenna launcher, so we decided we needed one of our own… and to make some design modifications in the interest of… “science”… plus our own sadistic pleasures. (Make sure you read below WV8TG’s initial “pressure test” experience.) The following pictures hopefully provide the basic concept and parts we used. Tom and I split the cost of the parts needed to make launchers and each built our own version, but they both are the same basic design with only length dimensions of the air chamber and barrel being the difference.
All parts where sourced from our local Lowes store in their plumbing department, except the Schrader valve which can be purchased at an automotive store. Total cost about $40 but you could make a couple of them as a joint project with a friend and reduce that cost per launcher a bit. I got a small rubber gasket for the outside nipple of the Schrade valve to act as another seal on the exterior of the air chamber. You will need to drill holes for Schrader valve, barrel slug stop and projectile slug caps to attach the screw eyes to attach the fishing line. I used 3 inch PVC for air chamber, 1.25 inch PVC for the barrel and short sections to mate the air chamber, trigger valve and threaded barrel. The projectile slugs were made from 3/4 inch PVC and caps and I filed off the nubs on the caps with a Dremel tool for a smooth fit into the barrel. I used PVC Prep on each joint before applying the glue. When gluing joints together, insert the sections together and twist a quarter turn for a solid adhesion. Let all glue set up for 24 hours before testing air pressure chamber. I will pressurize the chamber inside and let it sit overnight to see if it loses any pressure. It’s too cold right now to take outside in -4 degree temperatures to test, but I will use a bicycle pump with a pressure reading valve, and start at 40 psi… then 50 psi… and then 60 psi for test shots to see how it functions and check for any air pressure leaks. We use 60 psi for our club launcher.
WV8TG (Tom) charged his air chamber (barrel not attached) and let it set overnight to test for chamber air leakage. When he opened the trigger value… there was NO leakage… but there was a sudden LOUD release of 60 psi air gush out of a 30 inch long, 3 inch wide fully charged air chamber. He indicated the compressed air release was… impressive. However, his wife was not impressed… nor was she aware of the scientific test that was taking place. #surprise! #WHOOOOOOOSH #loudwifeexpressions I have no reason to doubt Tom will find his projectile slugs in the next county using his design. The club chamber was 12 inches long versus his 30 inch air chamber. #overkill? I designed my air chamber for 14 inches and will conduct all tests… outside. #potentialmeanwife
Well… the 2015 ARRL Field Day adventure is in the books… the logbooks, that is. Having experienced decades of Field Day excursions, this one takes the cake! What started out as a hot, sunny, humid Friday afternoon setting up our station high atop Chestnut Ridge, ended on Sunday afternoon having operated under conditions of torrential rains, a downward shift of 40 degrees in temperature, one antenna failure, one operator unable to man a station due to illness, a generator choked-out by all the moisture in the air and eventually walking around in a literal cloud! We had three layers of clothes on and could see our breath on Sunday morning! To say the least, it was a unique set of challenges to overcome.
Plan A was to slingshot and hang 3 doublet antennas, run 2 KX3’s for CW and PSK31, and run an Icom 7200 with a new Heil Pro 7 headset on voice. We had a 5500 watt generator and 25 gallons of fuel to keep us purring along. With 4 operators we had a good chance to keep all rigs racking up points for the duration. Laptops were ready to log and the plan sounded solid. The goal was to beat our score from Field Day 2014 and thought a good mix of voice and data would do the trick.
Our usual set-up has us mooching off of WR8S’s generosity when he goes to the trouble of of hauling his camper to the top of the mountain. We extend the awning and set up a table or two to operate from. Field Day 2014 was done via battery power and QRP mode.
The video below is a typical contest exchange using CW (Morse Code) and in the ARRL Field Day Contest an exchange of information would be the call sign of the other station, your operating mode (how many radios are you running and what sort of power and station are you running), followed by your section of the country. Then you return your own exchange to the other station and move on the to next contact by calling “CQ FD CQ FD de WT8WV WT8WV” and hope for a return of your call sign for a confirmed contact to log. CQ means “calling anyone”… FD means your are calling for the “Field Day” contest… de is French and means “from”… and WT8WV is our station’s “identifying call sign”. (You will see Bill (WR8S) make a contact and then write down the exchange from the other station on the log paper… then he begins calling CQ FD CQ FD de WT8WV using a memory keyer that he can program with the CQ message, our contact information and a thank you good bye message. He just needs to use the keyer paddles to send the other stations call sign during a contest.) Our return message to the other station to enter into their own log was, “WT8WV 2A WV”.
The pictures below tell the story of our challenges and our solutions. I have to admit I thought we were DOA when the generator croaked at 4:30 am on Sunaday… but we quickly came up with Plan X and realized WR8S had a converter in his truck! Back to battery power to finish of a good run of PSK31 and CW for 2 points each!
The original team plan was to use my new call sign WT8WV and be “3 Alpha West Virginia” but Jay got sick on Friday so we were now down 1 team member and 1 radio. Then we had a balun issue with 1 doublet antenna. So now we are WT8WV 2A WV with 2 Elecraft K3’s and 1 antenna. We decided to salvage our potential scores by focusing on PSK31 and WR8S’s speedy left hand on CW… and forgo voice comms.
You won’t believe how easy it can be! You take it in bite-size chunks of information and at your own pace. NO MORE MORSE CODE REQUIREMENT! (But Morse Code is a blast to still use and also the most efficient form of radio communication! I had to be able to send and receive 5 words per minute for the old Novice License… 13 wpm for General Class… and 20 wpm for Advanced and Extra Class licenses. There are no longer any Morse Code requirements and the Novice and Advanced Class licenses are no longer available.) For more than 100 years ham radio operators have been exploring the world and beyond from their own little ham shacks / ham station / living rooms. It never gets old and there is always something to explore!
What can you do with a ham radio? Talk to people all over the world with as little as 1 watt or less… or even 1500 watts. Assist in Emergency Communications. Assist with branches of the US Armed Forces. Build your own radios and equipment. Experiment with your own antennas. Go to fun “Hamfests and Flea Markets” to learn and get great bargains. Find new friends who are hams in your local club. Participate in the Annual ARRL Field Day Contest and exercises! Talk to the astronauts on the International Space Station. Talk to other hams around the world THROUGH many ham radio satellites orbiting the earth! Use your local VHF/UHF Repeaters to talk to family and friends from the car, handheld radio or from home. Track ham radio equipped balloon flights. Work with hams with disabilities. Refurbish or collect old time ham radio equipment. Teach others ham radio courses and/or help with exam sessions.
There are three different licenses you can obtain and they are designed in a way that as you study to get the first license, what you learn there will help you understand the next license study material. The really nice thing about it is that you will have ALL the multiple choice questions in each exam pool AND THE EXACT ANSWER TO EVERY QUESTION! That’s pretty good to have all the Q’s and A’s to study! The sample questions in your study materials are the EXACT questions you will see on the exam. A score of 74% gets you the license! There are also FREE practice exams you can take online or even from your smartphone! (I took a couple practice exams each evening as I sat watching TV in my favorite chair in my living room.) Soon the questions you have missed in the past practice exams are embedded in your brain with the correct answers reinforced! Each question will have four (4) possible answers; and on most of the questions you can just about eliminate two of the possible answers just by looking at them. (I will give you some good pointers about how to study and prepare for the exams at the end of this post! Read them before you buy any study guides or books!)
You will just need to do some interesting and fun reading, look at the questions (and the exact answers) from each chapter of the book… and before you know it you will be ready to take the exam! You are going to learn some really cool stuff each time you read the material. PLUS, as you advance to a higher class of Ham Radio license you can pick your own call sign! (In the early 1980’s my first call sign was KA8LJO from the FCC as a Novice Class licensee… then I was assigned KB8FIR by the FCC when I got my Technician Class license… and better yet, when I got my Extra Class license I picked my own call sign, WT8WV… “Whiskey Tango 8 Whiskey Victor”. I chose it for three reasons… I am fond of an occasional taste of good whiskey… I love my state of West Virginia… and phonetically it stands out and sings in a pile-up during a Ham Radio contest!)
The first license you study for is called the Technician License and the exam has only 35 questions! You will learn some very basic things about electricity, how your radio signals move through the air, some of the rules that the Federal Communication Commission (FCC) expects us to abide by for best practices, antennas, radios, the frequencies you can use in your new radio, and much more! You will gain legal access to some very good frequencies for both voice and data communication in several excellent ham bands. You could be ready to take this exam in a couple weeks of study!
The second license is called the General Class License and also has only 35 questions. This course adds to what you learned in the Technician Class study. It really dives just a bit deeper into some common things you will find will help you get more out of your antenna, radios, contesting, which ham bands magically open at specific periods of the day and year, some simply explanations of a few electronic circuits we use every day, and much more! You will also gain even MORE frequencies on the ham bands to use at your pleasure! You could be ready to take this exam in 2-4 weeks of easy study!
The third (and highest class of Ham Radio license) is called the Extra Class License and consists of a 50 question exam. This study course really dives deeper in what you have learned in the Technician and General Class license preparations. It will take a bit more time to study and prepare, and has a few more questions on the exam. You gain ALL frequencies allotted to Ham Radio communications, with several excellent niches within certain ham bands reserved for ONLY Extra Class licensees! You could be ready to take this exam in 30-60 days with some good study and practice exams under your belt!
The Amateur Radio Relay League (ARRL) also offers all sorts of study books for not only all the licenses but a myriad of way cool ham related stuff for every facet of this vast hobby! I have been a member of the ARRL for years and the monthly QST magazine alone is worth my dues! Plus you get discounts on all the other books and items. You can even find a local ham radio license class! http://www.arrl.org/find-an-amateur-radio-license-class Here is a link to the ARRL study guides for the three licenses. They are much more in-depth than the Gordon West series of license books and a good addition to your study… but I personally feel the Gordon West series in the best way to get that license quickly. Below for more information. http://www.arrl.org/ham-radio-license-manual
License Exam Study and Preparation Tips
Select which study book you will use for the license you are going to test for.
Find a quiet place to read.
Have a yellow highlighter handy to highlight things you might need to refer to for a question.
Study about 20 minutes a day. That way you won’t overload your brain!
Download a smartphone app with the ham radio practice exam questions and answers. I used this all the time whenever I had to wait around for something or someone… or in a boring meeting (once in a while).
Watch free YouTube videos to help you prepare or further understand the chapter. I have watched all of Dave Casler’s YouTube videos and they were a tremendous help to UNDERSTAND not just the question but the concept for every ham license book. He does each video by chapter or topic and they a short enough to consume in a sitting.
I highly recommend the Gordon West Technician Class License Value Pack for getting your Technician License quickly! I don’t get paid for saying this! Grin. However, I will tell your this is the best investment in getting a license you can find. Gordo makes it fun to learn and he tackles every question and answer in a way that will etch it deep in your memory. You will absolutely burn through the questions and he’ll teach you ways to remember even the questions that seem difficult for some reason. I have met him at the Dayton Hamvention and he’s a wonderful person and so helpful. He even gives you his personal telephone number to call if you have a question! I suggest burning the CD’s to an MP3 format and put them on your iPod, iPhone, Android or other device so your can listen to them anywhere… car, at lunch, on the treadmill, working out, hiking, etc. Worked for me every time I did my 30 minutes on the treadmill and lifting weights! (After I completed my Extra Class license with his book and CD’s I sold them for half-price to another General License ham in our club who is now studying with them! You could recoup some of your cost, too!)
I highly recommend the Gordon West General Class License Value Pack for getting your General Class License quickly! http://www.w5yi.org/catalog_details.php?pid=59&sort=4
I highly recommend the Gordon West Extra Class License Value Pack for getting your Extra Class License quickly! http://www.w5yi.org/catalog_details.php?pid=43&sort=4
Practice Exams, Practice Exams, Practice Exams, Practice Exams, Practice Exams!
These are free and a good way to see what areas you need to focus on so you can master a question. I did this about every evening during commercials watching TV! Great feedback on how you are progressing in your studies. When you begin scoring 80% on these practice exams you will be ready to sit for an exam! (If you buy the ARRL study books, they come with a CD with all the questions in the pool, the answers, scores your exams, shows you the areas you need to focus on, and tracks your progress by each section of the question pool.)
Getting you Ham Radio License is NOT rocket science… but it will be fun! It’s a hobby that is ageless. What happens if the cellphone towers don’t work, or if there is a prolonged power outage, or a natural disaster prevents normal communications? Ham radio operators are often the first folks getting the word out and getting the help coming in! I doesn’t have to be an expensive hobby, either! I have pieces of equipment I have either built myself or purchased dirt cheap at a flea market. I have also saved my money for some other items in my ham shack. It’s also a fun hobby to share with family, friends, and associates worldwide! GET ON THE AIR!
Click on picture below to enlarge it so you can see the frequency privileges you get with each license!
The Pro 7 offers a feature set that compliments the Heil Sound standard for headset design. Unlike copies of various aviation type headsets, the PRO 7 is not a copy. It brings newtechnologyto the headset industry. The 2″ thick gel foam ear pads provide extreme comfort for extended periods of time while exhibiting passive noise reduction rated at -26dB, ideal for use in high ambient noise environments. Using technology Bob Heil learned from Paul Klipsch back in the early 70’s, the ear cup enclosures were tuned to the free air cone resonance of the speaker cone thus providing very low distortion with maximum voice articulation providing the ultimate sound reproduction for communications. Theexclusive Heil Phase Reversal system (HPR) allows you to acoustically move the signals forward and creates a spatial widening of the sound field. This feature makes it easier to pull a weak signal from a pileup – useful for DxPeditions and contests as well as a stress reliever as your change the phase angle of the program source. A speaker balance control allows preferred level between the speakers.
The PRO 7 has interchangeable microphone system allows the microphone element to be easily changed in the field for different types of applications. The low distortion Dynamic HC-7 element exhibits a frequency response of 100 Hz – 12 kHz with the -3dB points at 100 Hz and 12 kHz. The traditional Heil speech articulation rise is centered at 2K -4KHz with properly balanced highs and lows. The impedance is 600 ohm. The HC-7 is one of our best microphone elements for speech articulation.
Designed exclusively for iCOM radios, the iC Electret element has a -3dB fixed point at 35 Hz and 12kHz with the sensitivity of-48 at 1500 ohms output centered at 1kHz. The iC element solves the problems with LOW GAIN ICOM radios but can also work with great results on newer Icom models. Bias power is applied to operate the iC electret element. The Pro 7 iC is supplied with our ADl-iC eight pin iCOM adapter cable.
The Pro 7 and Pro 7iC come in black, red, blue or pink.
The balance control located on the LEFT speaker, controls only the left speaker. Begin by setting a comfortable right side speaker level with the AF gain of the receiver. You then adjust the left side speaker where necessary to balance the audio between the speakers. In most cases the balance control will be close to or maximum.
In March of 2015 I took my test for Extra Class and passed with flying colors. I then did some searching for a unique vanity call sign that would have the letters “WV” somehow incorporated for “West Virginia” initials. None of the 1 X 2 calls were available, so I fixated on variations of a 2 X 2 call. I tried prefixes of W? A? K? N? followed by 8WV. After some thought for use in a contest, I settled on a “WT” prefix since you don’t tend to hear many “WHISKEY TANGO” prefixes… soooooo…
WHISKEY TANGO 8 WHISKEY VICTOR
A buddy of mine in the ham club said, “That’s a lot of whiskey’s…” I told him I am fond of whiskeys and love West Virginia… hence the new call sign. Eighteen days later the FCC granted my first choice and I retired my old call sign, “KB8FIR” and before that my original call sign from the early 1980’s was “KA8LJO”.
How GPS Works
Basic APRS – An Introduction
(Click link above for the ARRL APRS webpage explaining APRS)
“Official U.S. Government information about the Global Positioning System (GPS) and related topics”
GPS Modernization Video
GPS is getting an $8-billion upgrade
“Without it, ATMs would stop spitting out cash, Wall Street could blunder billions of dollars in stock trades and clueless drivers would get lost.”
New Satellites Could Make GPS Harder to Jam
“Without GPS, drones can’t fly, communications networks can’t function, and you don’t have a chance of figuring out how to get to your Aunt Sadie’s place in New Jersey. And right now, GPS is highly vulnerable because its weak signals are coming from an aging constellation of satellites.”
How GPS Receivers Work
“Our ancestors had to go to pretty extreme measures to keep from getting lost. They erected monumental landmarks, laboriously drafted detailed maps and learned to read the stars in the night sky.”
Check out the Air Force Collaboratory:
How Collaboration Leads To Great Ideas
How Robots Help Search And Rescue Teams
Voyager 1: Where To Next?