Category Archives: Antennas
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
I would venture to say you can’t do better than hearing it from the inventor himself!
Here is an excellent YouTube video from RimstarOrg that breaks down the concept of how crystal radios actually DO their magic! Yes, MAGIC. Radio signals are all around us 24 hours a day. Invisible! You can’t really touch them. You can’t smell them. You can’t hear them without assistance. We don’t really feel them bombarding us. We don’t sense those signals without some mechanical help… but they strike us with many different frequencies constantly… so let’s explore the range of frequencies we can decipher with a homemade crystal radio set!
THE BEST Multimeter Tutorial
The voltmeter… the Volt-Ohm Meter… the Multimeter… digital or analog… continuity… amperage, voltage and ohms… COME ON, MAN! What is it and how hard is it to use in the every day life of a ham radio enthusiast or just someone working in their workshop? Once again, Afrotechmods has an excellent tutorial on his YouTube channel for us to learn from!
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.
It was time to get a new 2 meter HT and I decided to get a dual band this time. I recently purchased on Amazon two Boafeng UV-5RV2+ radios for under $70 and like them very much. Here is the link for the Amazon deal… http://www.amazon.com/dp/B00IA9Q78W/ref=pe_385040_127541860_TE_dp_2
Here is a good video comparing the Baofeng and Wouxun Dual Banders…
I will need to add a better antenna to them but for the money they seem pretty nice. Audio is excellent. Programming them manually is a bit of a pain in the drain, so I downloaded the free CHIRP software and had them programmed in under an hour. Once you get a sense of the CHIRP software future changes will go smoothly. (I’ll post another video about using CHIRP.)
Any one who has EVER coiled wire, coaxial cables, audio cables or even a hank of rope knows UNCOILING it has at one time or another created a “rats nest” of tangled mess that will increase your blood pressure, makes you exceedingly cranky and often has caused Tourettes-like symptoms. Fighting an unruly coil of coax or audio cable wastes a lot of time when setting-up a gig, a Field Day site or even coiling a power chord at home! Having spent years working in television studios, control rooms, and other audio gigs on a daily basis, I learned early on from the engineers that there is ONE way to coil cabling… W2AEW shows that in his video! (P.S. Engineers can be especially grouchy if you don’t coil correctly and THEY get to untangle YOUR improperly coiled rats-nest from a previous gig tear-down as they work on an important production. Time is money.)
I have helped build and used two of these Doublet Antennas during the 2014 Field Day Contest and they worked great! Worked many stations on CW, Phone, and PSK31. Works great across many HF bands. A little over 120 feet long. WR8S (Bill Shultz), WD8WQK (Tom Graf) and I are going to make one for my ham shack as soon as I order the parts. Take a look at Ray Heffer’s explanation of the Doublet Antenna and a diagram by N4UJW below.
This video shows one way to use a scope and function generator to measure the length of a piece of coax transmission line as well as estimate its impedance. It uses a “poor man’s TDR” type of measurement by launching a pulse into the coax and measuring how long it takes to return after being reflected by the open circuit end. This same technique can be used to determine the distance to a fault (open or short). A simple method for determining the impedance of the line is also shown.
This video touches briefly on transmission line and reflection theory, but is definitely not intended to dive deep into these topics. There are literally books written about this topic – so that won’t be covered here.
John Shannon (K3WWP) kindly permits me to post his recent article here for your enjoyment. His contact information and websites are listed at the end of this article. Also, check out and join the NAQCC website at http://www.naqcc.info/
You can’t work DX on HF unless you run high power and have a big antenna farm. How many times have you heard that? Believe it or not even one ARRL employee was very skeptical about the ability to work DX otherwise. Maybe still is.
Anyway I’m writing this to dispel that notion. I also do it by example as many of you probably already know. Let me start by describing my station in detail. My rigs since I became active again in the early 1990s have been homebrew, Kenwood TS-570D, Kenwood TS-480SAT, Elecraft K-2, and now the wonderful Elecraft KX3. All have a couple things in common. They have never been used on any mode but CW. They have never been used at more than 5 watts output power (except for two experimental QSOs and one accidental one – that’s another story just mentioned here for 100% accuracy).
My antennas consist of a random wire most of which is in my attic for 160 through 30 meters, a 20 meters flat-top inverted vee in my attic, a 15 meters vertical dipole mounted on the side of my house, a 10 meters sloping dipole on my porch roof, and a 6 meters rotatable dipole in my attic. As KB7MBI puts it, that’s not an antenna farm, that’s an antenna victory garden.
With that setup I have made 19,140 DX (non-W/VE) QSOs since the early 1990s from at total of 219 countries (entities) on all continents and 36 of the 40 CQ zones. Currently as of May 29, 2014 I have made at least one DX QSO each and every day since March 1, 2013 – a total of 455 consecutive days.
With that preamble to let you know that I probably know what I’m talking about, I’m going to tell you how you can do just the same, probably even better if you have better antennas and a better location than I do. Oh, I neglected to say I don’t live on a remote hilltop somewhere, but right in the middle of a small town with its attendant man-made QRN. The town is located in a river valley with surrounding hills making a visible horizon of a couple degrees up to around 10 degrees.
I think the above proves it is possible to work DX with just 5 watts or less output and simple wire antennas. Of course it’s not as easy as working DX with 1 kilowatt and stacked 4 over 4 beams, but it’s not as hard as many hams think. I believe that ANYONE, without a great deal of effort, can get the basic DXCC award using nothing more than QRP/CW and a wire antenna. I worked 100 countries in just the first 78 days of the year 2000 as part of the ARRL Millennium Award program. Here are some tips to hopefully help you in your DX efforts.
Basically there’s not a lot you need to know to successfully work DX. First of all, a lot of good DX is only available via some high speed CW operators, so the faster you can copy, the easier it will be to work the DX station and move on to others. Of course since you don’t really have to copy a lot of info in most cases, you can get by at lower copying speeds. When you get right down to it, all you really need to copy is the DX station’s call, and your own call. But still you’ll be much better off being able to copy at least 30 WPM which is not all that hard to do with some good practice. If you can copy everything involved in the DX operation, you’ll be much more prepared to work the DX.
You also should know something about propagation as I mentioned in a previous newsletter. That way you won’t waste time in mid-afternoon trying to work DX on 80 or 40, nor time in the middle of the night trying to work something on 10 meters. Not to say there aren’t times mid-day DX on 80 or especially 40 is possible, or 10 meters DX late at night, but generally it’s not.
The most important thing to remember about DXing, no matter what power or antennas you are using, is to LISTEN before you do anything. Of course, before you can work the DX, you have to be able to hear it.
Once you find a DX station, you then LISTEN some more to find out the station’s mode of operation and just where HE is listening. For example, if you hear him work a station right on his frequency, then you know he’s listening there. Zero beat him and get ready to call, but again don’t jump in too quickly.
LISTEN to find out the pattern of the DX station’s exchange. When the DX is trying to work as many stations as possible as quickly as possible, the exchange should go like this:
Station – Sends
X2XXX – CQ DX X2XXX K
K3WWP – K3WWP
X2XXX – K3WWP 599
K3WWP – TU 599
X2XXX – TU
Sometimes after the exchange of info, the DX station will just say TU as in this example, and then start listening for replies. Other times he will send QRZ?, or QRZ? de X2XXX, or just X2XXX. Some stations send dit dit. Whatever it is, learn when the DX station is done with a QSO and ready for the next call before you jump in. Do everything right and you’ll have your QSO or at least a better chance at the QSO than someone who has no idea what is going on.
Of course that is the ideal situation, and it is not going to work that way every time, even for the most powerful station in the world, and certainly not for the QRPer with his wire antenna. Not to say it doesn’t happen, though. A few times I have beaten out a fair sized pileup to work a DX station. Why? Often it is simply favorable propagation, but there are also things you can do to help.
Be sure your signal is as clean and crisp as possible and your keying is as close to perfect as possible. DX stations often mention that it is not always the strongest signal that is easiest to copy in a pileup. Often a weaker clean signal with perfect keying is easier to copy. If you have a memory keyer, use that to send your call. It is possible to get nervous when trying for some rare DX, and be sloppy sending even our own call.
Another thing that helps at times is to delay for a second sending your call so that the last letter or two extends past the main buzz of the pileup. In my case, the DX station would then hear the WP and send WP? Then I send my call again, and make the QSO. That is assuming there is no other WP in the pileup, and everyone acts properly and does not transmit again if their call doesn’t contain a WP. And we know the odds of that. Generally anyone who has a W in their call transmits, everyone with a P transmits, and others will transmit even though their call has nothing close to a WP in it. The best of the DX stations in this case will send WP? KN KN and keep doing this until everyone else shuts up except the WP station. If a DX station does this often enough, he can really take control of a pileup and make it manageable.
If you’re totally aware of what is going on, you can sometimes catch a station switching from simplex to split (more about that below) operation, and be one of the first ones to switch. I’ve several times gotten an easy DX QSO that way. Or catching a station switching to another band and being the first one to do so and working him easily. Again that gets back to LISTENING which a lot of folks seem not to do.
If you keep calling him without an answer, try to figure out why. It could be that propagation is currently favoring another area. If he is working one W6 after another, and you are a W1, that could be the case or he may have his beam pointed to California at the moment. This is a good time to just note his frequency or store it in a memory in your receiver, and look for someone else. Come back later and see if the DX station is working stations in your area. If so, jump in and try again.
Some QRP stations like to sign /QRP at the end of their call in a pile-up. I don’t think it’s necessary, and I NEVER do it for the following reasons:
1. I don’t feel my QRP should be pointed out as a special situation. I’m just another station in the pile, not someone special because I’m only using 5 watts or less.
2. I am sure some QRO stations cheat and sign /QRP, and I certainly don’t want to be accused of that by those who don’t know that I am a 100% QRPer.
3. It does take an appreciable amount of time to send /QRP when you are dealing with running hundreds of stations per hour, especially if it has to be repeated. If I make a contact, there’s a chance I’ll have to repeat
my info since my sigs are weak, and repeating /QRP along with the other info may annoy not only the DX station, but others waiting in the pile. I hate slowing down DXpeditions or contesters like that.
4. To back up what I say in item 3 above, famous DXpeditioner G3SXW in his book “Up Two” urges operators calling him not to use /QRP. Then there is this quote from the 3B9C DXpedition web site to further denounce using /QRP: “We have received a few e-mails demanding that we amend logs to show /QRP. We are aware that some operators at 3B9C have been logging /QRP but it is DXpedition policy that we do not do so. /QRP does not form part of the legal callsign in any country and, as far as we are aware, no QRP awards require the callsign to be suffixed with /QRP. Therefore the /QRP suffix has no place in the 3B9C DXpedition log. You know whether you worked us on QRP or not and that should be all that is needed.”
If a pileup gets too huge and the pile obliterates the DX station, then the DX operator will switch to split frequency operation. This is when the DX station transmits on one frequency, and listens on another, usually higher, frequency.
If you hear a DX station say UP (or UP1, UP2, etc.), that means he is listening to a frequency higher than his. The number is the number of kHz higher than his transmitting frequency. Leave your receive frequency on the DX station, and set your transmit frequency UP to where the DX is listening. If he just says UP with no number, generally that means UP 1, but not always. Then you have to find the pileup yourself. Once you determine where the DX station is listening, follow the same procedures listed for simplex or same frequency operation. Just be sure you are transmitting and listening on the right frequencies. Every rig seems to have a slightly different way of accomplishing this. I’ll describe two ways it can be done with a KX3.
1. Tap the A>B button twice to copy the A VFO frequency and settings into the B VFO. Hold in the A>B button to activate split operation. Now the A VFO shows the receive frequency, and B can be tuned with the B VFO knob to set the transmit frequency. Then if desired, the headphones can be split via a menu setting so the DX is heard in the left ear and the pile in the right ear. That way you can hear who the DX is working in the pile in your right ear and the KX3 will then be set to transmit on that frequency.
2. Use the XIT feature to offset the transmit frequency from the receive frequency.
I always use #1 above, so I’m not totally familiar with XIT operation.
If the pileup is huge, you might be better off transmitting slightly higher than the main pile. The DX station will often explore the upper (usually) edge of a pileup if he can’t pick out calls from the main section of the pile. This is where the clever QRPer can often steal a QSO from the QRO stations. It’s really a chess game, and whole sections of DXing books have been devoted to breaking a pileup.
Often times the DX station will be operating split frequency but not saying so. This is where listening comes in. If you hear the DX working one station after another, but don’t hear any of the stations he is working, it’s time to tune UP and see if he is indeed working split frequency. Or you can go ahead and transmit on the DX frequency, and the self appointed DX policemen will very impolitely and illegally tell you the DX is listening UP. It’s always better to know what’s going on before you do any transmitting.
That’s enough about the pile-up type of DXing. If you want to know more, just get on the air and practice, or read one of the many excellent books that have been written about DXing.
Let’s touch on a few other DX topics at random. What about the QRPer calling CQ DX using his wire antenna. It’s probably useless most of the time, but I have had DX stations answer my regular CQ’s many times. This usually happens on 10M when conditions are really good, but it also happens on other bands. I currently have about 3 dozen countries worked via answers to my CQ’s. Strangely, my most distant QSO ever came when VK6HQ answered my regular CQ on 30M one evening. I was so shocked and excited I could hardly send. Even after the QSO, I was wondering if it was really true that I worked a VK6. It was, because I received his QSL card in a couple of weeks. However something like that is the exception rather than the rule for QRP CQ’s. Once in a while lightning strikes twice and a couple years later John, VK6HQ again answered my CQ on 30M. This time it led to a long distance phone call from John, and follow up Emails between us. This is one of the rewards of DXing – having one of your contacts become a friend.
The easiest time to work DX is in contests, because the best operators in the world often go to exotic locations for contests to make themselves more desirable or just to activate some rare country. Plus you have the super contest stations in various countries operating with their huge antennas and state of the art receiving equipment. They are the ones who can dig out the weakest of signals, and are glad to do so for those few extra points they will get in the contest. Those points may just help them beat out another top notch contester. You may have a tough time beating the pileups at the beginning of a contest, but often these super contest stations almost go begging for QSO’s near the end of a contest period. Then is the time you may easily work them.
Also for the week or so just before the big DX contests, many of the stations setting up for the contest will check out their equipment by working as many folks as possible. At these times they may also operate on the WARC bands (30, 17, 12) which are not available for operation in the contest itself. They often stay at their locations for a few days after contests also.
Always let the DX station dictate the type of QSO. If you answer a DX station outside a pileup, and he still sends just a report, you do the same. You will earn the respect of the DX station and those working him. There’s nothing more frustrating that having a DX station send only RST and the station working him sending seemingly his entire life history. If the DX station does send something like RST, QTH, and Name (OP), then you may be fortunate enough to find yourself with a DX rag chew. Send your QTH (maybe just the state), and name, and maybe mention you are running QRP. It doesn’t happen too often, but I have had some very nice rag chews with DX stations. I recall a few I especially enjoyed. I chatted for a half hour with a German who was on vacation in the Canary Islands. A PJ2 wanted to know all about my QTH. I had a nice chat with an Italian talking about my Italian heritage (my mother was Italian). A German asked me all about my QRP rig. A station in Haiti was new to operating CW and asked me several questions about it.
There were others as well. These are the DX QSO’s I find really rewarding, although I appreciate the RST only ones also. You CAN rag chew with DX using QRP when conditions are good.
There’s much more good info about DXing on my web site at http://home.windstream.net/johnshan/. I hope you’ll visit. I also hope you’ll be as successful as I have been working DX. I KNOW you can be if you just apply yourself.
73 and gud DX.
* John K3WWP – 100% CW / QRP – Proudly promoting Morse Code:
* On the air with my KX3 #2325, K2 #6418, KX-1 #02101
* As NAQCC VP – # 0002 FC # 1 – http://naqcc.info/
* As FISTS Keynote QRP Columnist – # 2002 – http://www.fists.org/
* With my CW-QRP site – http://home.windstream.net/johnshan/
If you are looking for coax, antenna wire, connectors, rotor cable, insulators, rope or the tools to make antennas Davis RF Company is a place I like to use.
Click link below to go to the Davis RF website…
BPSK31.COM does a great job of explaining how to get on the air with PSK31 technology. (Click link below for another excellent resource.)
W2AEW does a FANTASTIC job of explaining all sorts of nifty concepts in Ham Radio. I follow his videos on YouTube and spend many evenings learning from this fine gent! I also have some of his books as reference material.
I am gonna HAVE a scope some day!