AMATEUR RADIO OPERATOR TRAINING
TECHNICIAN, GENERAL and EXTRA CLASS LICENSE
Register Here for W4HFH 2014 Spring Training Session to learn & grow in ham radio
Beginning: Tuesday March 4, 2014 FCC Exam: Tuesday May 6, 2014 (10 weeks)
Start Time: 19:00 hours until 21:00 hours ( 7 PM to 9 PM)
Location: Alexandria EMS HQ – 3600 Wheeler Ave at intersection Duke St. and Quaker Lane
Cost: ARRL Study Book, FCC Exam Fee, and Class Study Materials $50.00
Chief Volunteer Instructor: Rich KA4GFY assisted by cadre of able and willing club member instructors who teach their discipline subject. For additional information email firstname.lastname@example.org or call (703) 969-6615.
Student Syllabus covers 400 question pool topics from which 35 questions make up license exam including ARRL produced PowerPoint Topics and Film Clips portraying historical evolution of radio communications. In addition, all exam questions can be previewed online with practice exam without cost. Learning Morse Code is NOT a requirement, but is encouraged.
ARC-SHORTS December, 2013
Rick Bunn N4ASX – Editor
Club Repeaters: 147.315 (PL 107.2), 444.6 (PL107.2), 224.82 (PL107.2), 53.13 (PL107.2) Down for replacement, 927.6 (-25Mhz, PL107.2), and 1282.600 (PL 107.2),
DSTAR 145.38Mhz, 442.060, and 1284.600
NEXT CLUB MEETING
Our next meeting is DECEMBER 13th at MANGO MIKE’S on Duke Street. It’s the annual Holiday party for the club. Ian N8IK is our MASTER OF CERIMONIES and you need to RSVP to him so he has a head count. Mango Mike’s website. http://www.mangomikes.com/groups.html pick off the Duke or Queen menu and let me know if your bride is joining us.
I forgot to ask this at the last meeting, but in past years, we have brought an inexpensive (< $20 gift) to the party, and anyone who brought a gift could pick one out of the pile when it was their turn.
Is anyone interested in continuing this tradition? Anyone planning on attending the party, please e-mail me, either on this list, or to email@example.com.
– Tom Kirby KJ4FUU, President
The holiday season begins with Thanksgiving, At this time I am thankful for the friendships we acquire as part of the club. For most of us it’s who we talk to on the radio and not what we talk about that makes amateur radio an interesting hobby.
OCTOBER MEETING MINUTES
Meeting called to order by President, Tom, KJ4FUU
ARC Meeting, was held on October 11th . The program was presented by Tom Dundzila KK4NMP, who presented a great program on how HF radio was used in the past to provide education for kids living in the Australian outback. Many of us are still trying to figure out what the radios were and who made them?? Tom, thanks for a very entertaining and informative program.
Another year has come and gone with hopefully all of us continuing to enjoy and learn from the hobby of amateur radio. We had opportunities for public service that went well (or at least better with us than without us), such as the George Washington’s Birthday 10K Run and Parade, the Marine Corps Marathon, the Bull Run 50 Miler, and Boy Scouts Jamboree On The Air, to name a few.
We’ve had radio contests with our club well represented by veteran HF operators, the Virginia QSO Party being a big one. We had a greater than normal number of operators who stayed overnight for Field Day, including a number of members participating in their first Field Day, and hopefully, getting interested in HF operations.
I’m looking forward to next year, and hope that we can keep up the participation level. The Virginia QSO Party is in March, and the February program will be a representative from SPARC, the club that sponsors the party. Also in February are the George Washington’s Birthday events, for which we need operators. I’m also hoping that we can have a Newbies On The Air event next year, when the weather is warmer, but not yet like a typical DC summer. I have several portable antennas, with vertical, loop, and end feds to choose from, along with my very portable Argonaut VI and LiFePo battery setup, so I can help a little with the event, even though QRP is generally not recommended as a starting point (but I did anyway).
For those with VHF/UHF capability, please keep George Washington’s Birthday on you calendar. On the Saturday before, we help out with the GW 10K Run, and there is room for members with HTs to assist.
Also, on the holiday itself, the city of Alexandria has the GW Birthday parade and asks the club members to assist. Aside from one mobile setup at the reviewing stand, and the radios in our trailer, the rest of the radios are HTs. We radio changes from the “final” version of the order of march from the marshaling areas to the trailer, so they can transmit the revised file to the reviewing stand. That way, the American Legion is not announced as Girl Scout Troop 104.
I hope to see everyone at the Christmas Party.
73, – Tom Kirby KJ4FUU
President, Alexandria Radio Club
Icom America has notified the user community of IC-7410′s that they now have a fix for the ALC overshoot issue that was identified in several of the early production runs, and has a process in place for owners to request the fix. This issue also pertains to the IC-9100′s, but Icom America has not yet notified the user community of a process for scheduling fixes for owners of the IC-9100 series of radios. For those who own IC-7410′s or IC-9100′s, you may be wondering what is an ALC overshoot issue? Basically, as outlined by W8JI on his website, www.w8ji.com/alc_exciter_power_overshoot.htm , an ” ALC overshoot, or power overshoot, is caused by the basic flawed design of ALC circuits and RF power control systems….The problem is rooted in group delay times as the signal makes its way through the radio to the output port…. The major problem with overshoot is voltage breakdown damage to amplifiers and components following the amplifier. This occurs in all amplifiers, from solid state to vacuum tube triodes. A secondary problem is bandwidth, with this problem mainly occurring or being most disruptive with tetrode amplifiers.”
To summarize, ALC overshoot can cause component damage or splatter or clicks when the user transmits when an amplifier is used. The issue with regards to ALC overshoot on IC-7410’s and IC-9100’s was identified by Adam Farson, AB4OJ/VA7OJ, in his in-depth analysis of the IC-7410 and IC-9100 (see: http://www.ab4oj.com/icom/ic7410/7410notes.pdf and http://www.ab4oj.com/icom/ic9100/9100notes.pdf . Adam is a retired telecom engineer and does a fantastic job in technically reviewing new rigs when they are first released and sometimes gets a manufacture’s preview of upcoming new rigs to examine. His website is well worth a visit.)
In general, based on K4IFG’s query to Icom, the process will be: “Icom US plans on contacting folks from their generated list and customers will be notified to ship to WA for necessary repairs. Repairs are to be first-in first-out basis and only several a week will be processed. Units are NOT to be shipped until notified by Icom US. Packaging should be a minimum of double boxing. If you have a problem, contact Icom US ASAP and get on their list – the sooner on the list – the sooner the repairs. Include serial number and date of purchase. It’s nice dealing with a vendor that stands behind its products.”
As mentioned earlier, Icom America does not currently have a schedule for fixing IC-9100’s, but there are supposedly plans in the works for owners of those units to have the fix applied to them as well. You can follow additional discussion related to the IC-7410 or IC-9100 on the Yahoo groups, firstname.lastname@example.org or email@example.com .
73, Marshall KI4MWP
NOVEMEBER MEETING MINUTES and ELECTION RESULTS
Meeting called to order by President, Tom, KJ4FUU
Seventeen Members and 4 guests were in attendance. Tim O’Neill, KT4MV presented fox hunting via loops, time difference and Doppler techniques. Also included were direction finding techniques used in the past by various groups including the military and FAA. Tim was made a honorary lifetime member by the club recognizing his selfless effort in maintaining our multiple club repeaters.
- Basic Checking: $984.73
- Communications Trailer: $855.32
- Education Fund: $2,312.32
- Regular Shares: $5,225.08
- Total Deposit Accounts: $9,377.45
Secretary’s Report: No change.
Education – KA4GFY. December 10th is the exam.
Repeaters – Tim, KT4MV. Two m OK, 900Mhz OK 1200 Mhz OK 220 OK working to get 6m by end of year. 440Mhz audio is dropping out will work this in future. Might use two old Motorola’s to get 440 working quickly. Also need to make a new cable for 440Mhz repeater.
Trailer – Rich, KA4GFY & Rick, N4ASX & Doug AK4QY. No changes briefed.
DSTAR – KI4MWP. Experiencing a linking problem with disconnects. New software in last month may need to be changed.
Webmaster – Roy, K4AXQ Not present.
ARES – Rick, N4ASX. Not present.
Christmas Party – Ian, N8IK. Please get info to Ian on who will attend and desired menu selections by 9 December 2013. He needs the count for the restaurant.
New officers were nominated and elected for 2014. They are as follows:
Tom Kirby, KJ4FUU – President
Larry Walker, KK4CBL – Vice President
Eric Misavage, KI4BXU – Secretary
Steven Wagner, W8RJH – Treasurer
Net Controls for the next period:
- Nov 14 – KA4GFY
- Nov 21 – W9TCE
- Nov 28 – No net
- Dec 5 - N8IK
- Dec 12 - KJ4FUU
Jeremy, KF7IJZ, has decided to remain with the club.
Meeting was adjourned by the President, Tom, KJ4FUU.
Its time to look for hamfests on next year’s calendar. The first hamfest in the area is the Maryland Mobileers hamfest on January 26, held at the Odenton Volunteer Fire Department. The Richmond Frostfest rolls around a week later on February 1 at the Richmond Raceway Complex and the Vienna Winterfest at the Annandale Campus of Northern VA Community College on February 23. Its not that far off.
Our current class started on October 1 and now wrapping up with the exam on December 10. If you are looking to upgrade to General or Extra with 15 students now enrolled. The exam date is December 10. If you are looking to upgrade, be sure to let me know so I can make sure to have enough General and Extra tests on hand.
Our next class will be starting on March 4. I am already fielding questions for the next class.
December 6 through 8 – ARRL 160 Meter Contest (CW). Exchange is the RST and ARRL Section. With a little ingenuity, you CAN get on 160.
December 14 and 15 – ARRL 10 Meter Contest (CW and SSB). Exchange is RS(T) and state or a serial number for DX stations. If the band is open, this is a great contest. You will have more trouble working closer stations than DX stations.
December 22 – ARRL Rookie Roundup (CW). This is a contest where the new ops get to shine. The exchange is both calls, name, check and section. Like the Sweepstakes, the check is the last two digits of the year you were first licensed.
December 28 – RAC Winter Contest (CW and SSB). Exchange is the RST and serial number for non-Canadian stations.
We also have a couple of non-contest operating events that are worth noting.
December 6 – NWS Skywarn Recognition Day. The object is to work as many of the participating National Weather Service stations as possible. The exchange is the weather conditions at your location. Check the NWS Skywarn page for the times and frequencies the stations will be on.
January 1 – ARRL Straight Key Night. Not a contest, but friendly QSOs between stations is the norm. Instead of sending an “RST”, use “SKN” to clue others into Straight Key Night. Some operators really can send code at 35+ words per minute with a straight key and it’s a pleasure to listen to.
73, Rich, KA4GFY
Radio Spectrum, Use it or Lose it!
Unless you are a recent licensee or have been under a rock for several years, you know our spectrum is very valuable real estate in the word of communications, particularly the spectrum above 420 MHz. The cell phone companies would love to latch on to some of our spectrum in the Gigahertz region and Congress recently made a grab for spectrum we share with DOD in the 420 to 440 MHz to farm out to commercial users. They no no clue there was any amateur actity there. This is not uncommon. Thankfully, DOD stepped in and reminded Congress those frequencies are being used by DOD, so buzz off.
Some time ago, there was even an idea to put low earth orbiting satellites on 2 meters for internet access. When ARRL raised many red flags about the incompatibility of hams ragchewing and people surfing the internet at the same time, the company’s “engineers” stated we could both share the spectrum with no problem. NOT. ARRL proved them wrong. The engineers knew about computers, but nothing about radio.
Let’s not forget the fiasco with the lower 2 MHz of our 1.25 meter band. At one time, hams had access to 220 to 225 MHz. The lower two MHz was primarily used for weak signal work, as well as linking and control frequencies for repeaters. One radio company that is no longer in business had an idea for a new operating mode on VHF, but had no place put this new mode. So, in looking for a place to put this new mode, they looked at a repeater directory and decided the lower two MHz of 1.25 meters was a good place. After all, hams were only using the top 3 MHz of the band, for repeaters. Never mind the fact we don’t publish linking and control frequencies, for good reason. So, this company convinced the FCC that hams weren’t using that portion of 1.25 meters, despite an outcry from ARRL and concerned individual amateurs. When it was all said and done, we lost the bottom 2 MHz of a really great band and caused what we call in the accounting world “negative goodwill” with the FCC because we called out the underhanded way in which this was done.
The bottom line is we need to make sure our ham radio frequencies are being used. If you participate in contests, be sure to send in your score. This data is used by the sponsors as proof our frequencies really are being used. If your entire shack is a handheld and you only operate VHF and/or UHF, be sure to announce yourself on the repeater. Somebody is out there. Maybe not all the time, but keep at it. There are great contests for VHF and UHF operators. If you are into DSTAR, there is a QSO party for DSTAR.
If we make use of our very valuable radio spectrum, we can keep the spectrum we have. Our VHF and UHF spectrum is a prime target for expansion of commercial users. Congress is looking to close the budget deficit by selling off radio spectrum. Let everyone know we ARE using it. Get on the air!
73, Rich, KA4GFY
For those who are not able to make the party, We wish you all a Merry Christmas, or happy holidays and a wonderful New Year.
Monday Night Half Price Burgers – There is a group that gets together at Shooter McGee’s (Duke and Paxton Streets) on Monday evenings at 6:15 PM. A good burger and soft drink runs about $9.00.
Jeremy’s IC 7100 UTUBE LINKS
I am in the process of answering your reception reports from the past weekend’s VOA Radiogram.
Some of you are doing some interesting experiments with the digital modes on VOA Radiogram. And some of you are letting us know about some useful techniques to improve both the production and the reception of the program.
Mark, WA4KFZ, notes that the SSTV Denoiser software, part of the SSTV Tools suite from dxatlas.com/SstvTools/, can be effective with some of the “noisy” MFSK images you receive on VOA Radiogram.
In this weekend’s VOA Radiogram, one VOA News item will be in the MFSK22 mode (80 words per minute). Unlike the MFSK 16, 32, and 64 modes, which have a sample rate of 8000 Hz, MFSK22 has a sample rate of 11025 Hz. For this weekend’s program, I recorded to one track at 48000 Hz for the voice introduction and closing music, one track at 8000 Hz for MFSK 16 and 32, and one track at 11025 Hz for the MFSK22 item. Then all three were mixed to one .wav file with a sample rate of 48000 Hz.
Another “feature” in this weekend’s program will be five seconds of silence whenever modes are changed. This might improve the performance of the RSID.
The Flmsg-formatted VOA News story in this weekend’s program is 9 minutes, 6 seconds long. That might seem unusually long, but it includes 4 minutes, 20 seconds for a VOA logo in SVG format as part of the html. This was created for us by Mark Hirst in the UK.
Here is the lineup for VOA Radiogram, 10-11 August 2013:
- 2:30 MFSK16: Program preview
- 3:26 MFSK22: VOA News re import of Apple products
- 3:12 MFSK32: Greetings to l’Associazione Italiana Radioascolto
- 2:10 MFSK32 image: AIR logo
- 9:06 MFSK32/Flmsg*: VOA News re one year of Curiosity on Mars
- 2:26 MFSK32 image: Curiosity tire tracks
- 1:10 MFSK16: Closing announcements
- 2:20 Surprise image, text, image of the week
*To make Flmsg work with Fldigi (both can be downloaded from w1hkj.com), in Flmsg: Configure > Misc > NBEMS — Under Reception of flmsg files, check both boxes, and under that indicate where your Flmsg.exe file is located.
Please send your reception reports, audio samples, screenshots, comments, ideas, suggestions to firstname.lastname@example.org .
Hamvention Event 2013
The Alinco DJ-G29T – 1.25 meter and 33 cm bands My major purchase at the Dayton Hamvention this year was the Alinco DJ-G29T handheld radio. This particular model has some special significance for us in the Alexandria Radio Club because a couple of years ago at the Hamvention, Marshall, KI4MWP, put a bug in the ear of the some of the Alinco engineers to design and build a handheld radio that will work the 1.25 meter and 33 cm bands. Alinco was the only manufacturer marketing a handheld on 1.25 maters and the only way you could get on 33 cm was converting certain commercial equipment. At the 2012 Hamvention, Alinco had a mockup of what the new handheld would look like. By the 2013 Hamvention, the DJ-G29T was a reality.
Playing with it the hotel room Friday night, I realized the automatic offset needed to be turned off. A quick look at the manual and I figured out how to do it. A word of caution here, the manual was originally written in Japanese and translated into English, so some of the grammar and sentence structure requires some thinking to make sense of what it’s saying.
The 1.25 meter of the radio worked well, while I managed to bring up a few 220 repeaters in Dayton with no trouble, even managing to turn on the correct CTCSS tones. When I switched to 900 MHZ, the radio reverted to auto duplex and I had to turn it off again. 927.500 MHz is the national simplex/calling frequency on 902 MHz, but the radio kept thinking it should have been a repeater. I managed to make a contact on 900 MHz simplex with somebody in a nearby hotel, so we both decided the radio must be working correctly.
Having owned the radio for two plus months now, my first observations are that it’s a very nice radio. It has a nice feel to it. The power button took a bit of getting used to, but after awhile, it is not much different than any other radio. I found the first few times programming the memories, it was helpful to have the manual close by. With the manual guiding me, I was able to load frequencies into the memories with relative ease. One thing I found with the memories is if you put a name into the memory channel, that is what is displayed, not the frequency. Not a major problem. I would rather know the frequency than which repeater I’m on. I know which repeater I’m on by the frequency.
So far, signal reports have been positive on both 1.25 meters and 33 cm. The receiver has plenty of audio and the transmitter sounds very clean. The transmitter is rated at 5/1/0.4 watts on 1.25 meters and 2.5/1/0.4 watts on 33 cm. That will work most anything in the local area. It comes standard with a 1.2 AHr battery pack, which I find is plenty for what I use the radio for.
I will say for most of my VHF and UHF radios, I’m an ICOM guy. I can usually have an ICOM up and running in a few minutes. There was a learning curve here. This was my first venture into Alinco territory.
I applaud Alinco for diving into this niche market. Perhaps this will encourage hams to try these two bands. With activity comes more options for equipment. While there are not a lot of 33 cm repeaters on the air, there are quite a few 1.25 meters repeaters. All it takes to generate activity on a new band is for a few hams to buy equipment for it and start using it. This is great news for hams because we now have a 33 cm radio that is VFO programmable and has the memory capacity we have become used to. (Us old timers remember crystal controlled VHF/UHF gear or only 10 memories).
Having said all that, you may be wondering why I bought this particular radio. Well, the Alexandria Radio Club is the proud owner of repeaters on both 1.25 meters and 33 cm. Both repeaters are commercial grade and sound great. They just need more activity. In fact, the August 2013 issue of QST had an article on the 33 cm band. Not only that, N4ASX still has a few of the Motorola GTX handhelds that need a forever home.
73, Rich, KA4GFY
Bull Run Event
Alexandria Radio Club supporting the Bull Run 50 on April 13th showing the finish line, Net Control operators (KA4GFY andKI4D) the race director (Anstr Davidson) and the club trailer. Others Club members participating were Jeremy Kolonay, KF7IJZ and Chris Sullivan, KJ4QEG.
September 2013 ELMER’S Corner – Mobile Antennas
Many new hams start with a handheld because it’s an all in one arrangement. All self contained, no need for a power supply, additional antenna / feedline or external microphone. But, soon after we all find out that the antenna on the radio is not good for any real range. The next step is usually a mobile whip of some kind put on a metal plate or file cabinet. This magnetic mount antenna also works for going mobile.
We’ve covered some homemade portable antennas, but let’s look at mobile whips. In the past we worried about ONE band at a time, but many now have dual band radios (2m/70cm) and there are many mobile antennas that will do this.. One we overlook is the 2 meter quarter wave. A 19.25” whip. Because 70cm is the third harmonic of 2 meters, the simple quarter wave will work on 70cm. Nice thing about the quarter wave is that it is small enough so that it can be placed on the roof of your car and not cause in door parking problems.
If your working just one band or need more gain, look at the 5/8th wave antennas. This antenna flattens the pattern and give you an effective 3db gain so your 5 watt handheld sends out 10 watts Effective Radiated Power (ERP). Unfortunately, the 2 meter 5/8th wave will not work on 70cm, but it will work as a ¼ wave on 6 meters. Some of these antennas can be found at hamfests cheaply.
There used to be many types of mounts that could be found either on mag mounts or as installable by drilling a hole in the vehicle. These days the most popular is the NMO or Motorola mount. Shop around for mag mounts they can be expensive. I purchased one with a BNC connector for $32. The advantage is that you can use it in the home or on the vehicle.
I have also used the 3/8s thread mounts which are common to the HF whips and CB whips. At hamfests you can find the Hustler 5/8ths antennas (Buckbuster) fairly cheaply and Hustler use to make a family of collinear antennas that provided 7db of gain but it is a BIG antenna and it only works on 2 meters. I have one for 2 meters and one for 220MHz and they work well.
Comet and Diamond make dual band and other antennas that work well but any multi-band antenna will be a compromise.
73 Rick N4ASX
August 2013 ELMER’S Corner – HF Antennas cheap and stealthy
With VHF and UHF we found that you can make several inexpensive antennas. VHF and UHF antennas are small by comparison with HF (High Frequency) antennas. The fundamental focus should that the size of the antenna is related to the ¼ wavelength of the frequency. So
As you go down in frequency your antenna must be larger. While there are LOTS of small antennas that suggest that they can perform as well as larger antennas, the math does not support the claims.
The simplest antenna is a dipole (2 ¼ wavelength wires attached to the coax center and ground. But many of us cannot run a coax out to the center of a dipole and stay stealthy. Two alternatives for a resonant antenna are a vertical which can be a vertical dipole or a ¼ whip with a ground plane. For the 20 meters you might run a vertical wire from the ground up into a tree and run four or more quarter wave radials (wires along the ground or buried in the ground. If you can mount the vertical radiator on a metal plate you are in good shape. When the sunspots are high then you might go with a 10 meter vertical and you could use an old CB (11 Meter) whip and cut it down.
One of our members has a copper water pipe antenna. He uses heavy pipe with a threaded coupling so he can make it 10 meters, 15 meters or 20 meters. He uses hook up wire for the radials and a screwdriver stuck in the ground to insulate the radiator from ground.
One other member used aluminum drain pipe on a wine bottle as the vertical.
Another alternative is the random wire. If you can put lots of wire between your balconies or someplace close to the feed point you can run the coax outer conductor to ground and attach your wire to the center conductor and run as MUCH wire as high as you can. You can use copper weld or other light weight wire so that it’s hard to see and run it to a faraway tree. As this is a non-resonant antenna, you will need to use an antenna tuner to make the wire antenna resonant for each band you operate. One ham was on the 9th floor of an apartment and ran 250 feet of thin magnet wire to a fence around the parking lot and he worked over 200 countries on 100 watts.
Mobile whips will work but they are inefficient and usually on resonant for a narrow range of frequencies, but if you put a ¼ wavelength wire counterpoise or two or more radials you can still work the world.
July 2013 – A Cheap 220 Mhz Yagi
Good news! The Alexandria Radio Club has an operative 220 Mhz repeater. The only problem for me was how to hit the repeater with a handheld radio from where I live (in Burke,Va).. Five watts is not a lot of power so an antenna was needed that would provide some gain. Three to 5 db gain would be great. Oh, did I say also cheaply?
A good discussion for the beginner to Yagis is at http://www.hamuniverse.com/yagibasics.html
I needed a suitable design for the frequency of interest 224.82. A quick way to obtain a designed antenna was to use the QY4.exe tool developed by WA7RAI.. It may be found at http://www.dxzone.com/dx451/quickyagi.html Under the Quickyagi icon you will find a link: http://www.astro.hr/ucionica/radioastronomy/antenna/qy4.zip
Download the file and unzip it. QY4 is a DOS program and is old, but useful and free. A setup file to install the software is included with the downloaded zip file. I used the Auto Mode selection for design and selected “Auto-design a Yagi”. You will next be asked for the following:
- Frequency? 224.82.
- Are all elements the same diameter? Y
- # of Directors? 2 (I only selected two directors to keep the size small).
- Element Diameter? (I answered .1 inches – the diameter of the welding rod to be used.
Next QY4.exe will give you the design data for the antenna
You could actually stop here and have a useable antenna. However note the input impedance of 34.2 Ohms. You can opt to use a 2:1 Balun to match closer to the 34 ohms (more expense) or if you just use the 50 ohm cable losses are not too high. I just used an unbalanced connection and matched directly to the 50 ohm coax. After all ,we are going cheap, here.
For my antenna, I elected to use another piece of software EZNEC ver. 5.0.54 by Roy Lewallen. It is $89 or if you choose to just use the Demo version, free. www.eznec.com/demoinfo.htm (The Demo version is restricted in the number of segments allowed to 20 whereas the commercial version allows use of 500 segments). Even with only 20 segments you can still design simple antennas.
I input the information from the Quick Yagi output into EZNEC5’s input side and optimized the gain for the planned height above ground by adjusting the driven element dimensions in EZNEC. Finally the results were as good as could be done quickly and I was ready to build the antenna.
To start the project, a quick survey of the junk box. Things I found were short pieces of wood from past projects, some scrap sheet metal and a piece of coax with a connector attached. Now suddenly I saw a package of acetylene welding rod not currently being used that was copper coated .
(See list of materials used, below)
First step was to select a piece of wood large enough to accept the welding rods and antenna connections. As you will notice on the Quick Yagi output the boom had to be over 1.71 ft in length to hold all the Yagi elements. A piece 24 inches long by 1 inch wide was available in the scrap box, so it was used.
Next the holes were drilled for the welding rod elements. (Be sure to make the holes a snug fit for the elements otherwise they will slide around when finished).
I inserted the welding rod for the driven elements into some solderless fasteners to provide a connection that could be removed if needed. Then the elements are inserted into the wood and centered. Notice the driven element consists of two individual pieces and that they do not touch each other.
The Coax connector cable ends were soldered to each of the driven element connectors using the solderless fasteners.
The frequency of 224.82 Mhz is above what most antenna analyzers can handle. So tuning is really dependent on an accurate design.A clamp for the coax was made from a scrap piece of sheet metal and secured with two screws.
Note that if this antenna is used outdoors the wood parts of the antenna should be painted with polyurethane or some weather protectant. Also the metal elements could be sprayed with clear lacquer to protect the copper. If used inside be careful of large metal objects – particularly metal window frames. They can really adversely affect the VSWR and the gain.
If you have questions, you may email me at KK4CBL@arrl.net and I will attempt to answer your questions. 73s, Larry Walker KK4CBL
July 2013 – Antenna Feedlines and Connectors
So far, we covered buying used radios, cheap antennas and power supplies. Let’s talk about antenna feedlines and connectors. I was getting ready for Field Day and putting the newsletter and I read Harry’s meeting minutes. The simplest VHF antenna is the roll up J-pole with the details in the May ARC SHORTS. It dawned on me that most of those who will want to build one of these antennas will want to use it with their handheld VHF radios. In the past these radios had BNC connectors so we used BNC to PL-259 (UHF) adapters, but now handhelds use an SMA connector. SMALL and maybe a bit difficult to put on our antennas. BUT, I wanted to give it a shot, so I called my favorite connector, cable place and ordered a bunch of connectors including some RG-8X SMA male connectors. WOW – in one paragraph I tossed a great deal of jargon at you and your lost in it. DON’T STOP READING – I Shall endeavor to explain.
There are two types of feed lines for antennas, the balanced line or twin lead that we use to use for our TV antennas. Twin lead is very efficient but can be a pain to feed through a wall or work with. Good for HF but not so good for 50 MHz and up. COAX is the cable with a center conductor, an insulator around that center conductor and an outer conductor over the insulator and then an outer plastic or rubber jacket. It comes in several impedances (50, 75, 92 ohms) we are interested in the 50 ohm cable. Now there are THREE sizes that we generally use. The big stuff is 5/8 in diameter can be RG-8, RG-213 (Mil Spec RG-8), Low loss versions are LMR-400 or 9913. There are charts in the ARRL handbook and antenna book to show the loss of each type of coax. This stuff is great for the home, but can be a problem when portable or installation in a car. The next step down is RG-8X. This is the smaller diameter stuff and 8X is almost as good as RG-8. I use RG-8X for mobiles, and portable / Field Day / Public Service operations. 100’ of this stuff is a lot easier to deal with then 100’ of RG-8. If you’re going CHEAP, then there is RG-58. This is slightly thinner than RG-8X and not near a good, but it’s the stuff you can buy at Radio Shack for 19 cents a foot or less.
Most mobile radios (CB’s as well) have a standard Coax connector on the back. In the industry it’s called a UHF connector. The female connector is also known as an SO-239 and mates to the PL-259 on the coax feedline. So, if you buy a VHF mobile you will want to make up a feedline with a PL-259 connector that goes with the coax you chose to use. If your using a new handheld the little connector on the handheld is an SMA connector. Most of us do not put the SMA male connector on the coax, but buy an adapter to convert the SMA to the UHF Female (SO-239) and then connect our coax with the PL-259s to the adapter. Some adapters convert to a BNC connector. The BNC is what was used on UHF and up radios and handhelds before the SMA. It’s a bayonet type connector. An important point here is that adapters cost power on transmit and some receive sensitivity.
Now we have three kinds of coax and three different kinds of common connectors. Now I will toss in one more variable. Two kinds of connectors. The standard for most is the solder on connector. The solder on UHF (PL-259) for RG-8 you cut the outer conductor back exposing a length of the center conductor and insulator and cut the insulator back so you have a little exposed center conductor (about ½ inch) another 1/16 inch of insulator and then about ½ inch of outer conductor exposed. You first put the screw collar over the coax, then you put the connector body over the end of the coax and screw the outer conductor into the connector body while having the inner conductor feed into the center pin of the connector, solder the inner conductor to the pin and there will be holes in the outer side of the connector body that will show you the outer conductor. This becomes a talent issue. You want to place solder into those holes and get a good solder connection WITHOUT melting the insulator between the inner and outer conductor of the coax or the insulator in the connector. I use a 250 watt soldering gun for this.
Another approach is the CRIMP on connector. About the same initial fit up but you also put a collar over the cable with the screw on piece. Solder or crimp the center connector and then the insulator goes inside the connector body and the outer conductor goes outside the connector body, then there is a crushable collar that slides over the outer conductor. Here is the fun part, you get your crimping tool and crush or crimp the collar down onto the outer conductor. Faster and unless your really good with the soldering gun works better. The cost of the Crimp kit is about $100 but the connectors are about 50 cents cheaper and not redoing the connectors will pay off.
Now if your using RG-8X or RG-58, the solder on connector is the same but you add a sleeve over the smaller coax. There solder on PL-259 can be more like the crimp connector. The outer conductor is folder over the adapter sleeve. And then the coax with the adapter is put into the PL-259. Solder the center pin to the inner connector and then with two pairs of plyers you tighten the adapter into the body. You can then solder through the holes in the connector body, but you don’t need to if you can tighten the adapter. Crimp on connectors for RG-8X and RG-58 work like the standard but have a smaller body for the smaller coax, no adapters to buy or look for.
If your working with older radios or military gear you may have to work with the BNC connector. One of our members called these BAD NEWS CONNECTORS. The center pin is soldered to the inner conductor and any excess solder may cause problems
June 2013 – Power Supplies
Last month I talked about cheap, homemade VHF/UHF antennas. I’ve already gone over the availability of used and inexpensive VHF equipment.
Now you find that your new handheld doesn’t quite make it to the repeaters you want to operate on so you’ve tried an antenna from the list of DIY designs and still not good enough. You’ve also found out that needing to recharge your handheld batteries is a pain and holding you radio sometimes leads to hot radios and lots of weight.
The next step is to find a used mobile two meter radio and as we covered before, you get one with CTCSS / PL encode and between 10 and 50 watts output. Now comes the need for a power supply to make it work. Your happy that you only paid $100 for the radio and $15 in parts and coax for your antenna, but now you find you need a power supply for that new radio.
Now, How many amps do you need. If your running your handheld at 5 watts then figure P = IE with 5 watts out this would indicate that you need 5/12 amps, but you also need to remember that the output is only from the final amplifier of the radio and does not cover the other components. Best rule of thumb is to go for 5/12 * 2 (assume that you will need twice what the finals use). So for your 5 watt handheld you need about 1.7 Amps. There are many 7 Amp and 10 Amp supplies available that will work. If you’re running a 10 watt radio that would be about 3.5 Amps on transmit but again 7 or 10 are available. For a 50 watt radio most of us would go with a 20 Amp supply. The 20 Amp supply will provide sufficient current for a 50 watt or more mobile and also sufficient current for most 100 watt class HF radios as long as you do not transmit on both at the same time.
If you go for a commercial power supply, there are two kinds. One is the basic power supply and the other is a switch mode power supply. The switch mode power supply converts the incoming AC into DC then converts it to AC at a high frequency. The higher the frequency the small the transformer. Switching supplies are more expensive but much smaller and lighter.
Several solutions come to mind.
1 – You can build your own. You will need a AC cord with plug, a transformer from 117AC to 24 -30 Volts AC, Diodes that can handle the current you need, a few electrolytic capacitors and maybe an inductor to filter the rectified AC. See the Amateur Radio Handbook or the web for detailed designs. Not a hard project, but,
2 – Look for a used power supply at a hamfest or from someone in the club. New commercial power supplies go from $60 to $200 for the kind of current you might need, so you should not pay more the $70 the basic 12 VDC supply.
3 – A cheap way to go is also to find a car battery ( or marine deep cycle battery) or even a 35 Amp Hour sealed cart battery can work and buy a cheap car battery charger. The battery provides the filtering and high current when needed and on receive. If you have a car battery you’ve recently replaced then all you pay for is the core charge. You will find that buying a new battery may set you back as much as a new power supply, but you will also get a back up source when the power goes out.
4 – Buying a new supply. Good names are Astron, MFJ, Radio Shack, Samlex, Jet Stream and Diawa. Most of them have good protection circuits and many now have Anderson power poles. These power supplies (20Amps go from as low as $85 (MFJ).
If I had an old car battery, I would start with that, and then go to the hamfest looking for a used power supply. Take a volt meter with you and have your ELMER look at it if you have any questions. The Astron 20 Amp power supplies sell on the web for $120 new. Some of the switching supplies can be had for the same price on Amazon or from ham radio stores, so offer less for a used unit. A new power supply is not a bad investment as it will also support other gear.
Connectors are a consideration. Most VHF/UHF radios now use a T-Connector but many of us use Anderson power poles. Rather than cut the T-connector, I usually leave the T-connector in place and put Anderson 20 Amp power poles on the cable. If the power supply has binding posts, make up a short piece of 10 gauge red/black cable with Andersons on one end and ring connectors for the binding posts on the other. Just wrapping stranded wire on the binding posts will cause problems later.
May ’13– VHF Antennas for Tech and others
Our weekly nets do not reflect the club’s membership. Some of the problem is that the success of our classes has brought in many new members. Ham radio can be a very expensive hobby with the old Cushcraft Ringo costing over $100 and the Diamond and Comet sticks costing even more, may keep some of our new operators from putting up an antenna for 2 meters. Another issue may be restrictions place on us by home owners associations or building management.
There are some stealthy solutions. The first is the ¼ wave ground plane antenna. All you need is 5 – 19” pieces of copper wire (from 10 Ga. Romex is ideal). Take an SO-239 chassis connector and solder the vertical element into the center of the connector, try not to melt the insulator. Then you can solder the four ground plane elements to the four screw holes, but if you want to add a mount you can bend a small piece of sheet metal and drill a hole for the connector and the four mounting holes and use four screws to secure the connector and the radials to the mounting plate. Drill holes for a U bolt to secure the antenna to a small piece of 1.25 in TV mast. Feed it with a small run of RG-8X or RG-58 with a connector that matches your radio and you will have a much better antenna then the rubber duck on the hand held. Another cheap antenna is the coaxial dipole. Take one end and fold back the 19” of the outer conductor back over the plastic outer jacket of the coax leaving 19” of the inner conductor and insulating jacket exposed. At the end of the outer conductor make an RF choke by rolling up four 6” diameter loops and taping them together. The remainder of the coax should reach your operating position. Add your connector for the radio at the other end. You can hang this antenna up either outside or near a window. Another design that has some gain is the J-pole which can be made with TV Twin lead or ladder line.
Tools: Ruler, Wire strippers, Wire Cutters, SolderingIron.
- Measure 54″ of Twin lead and mark this spot with some maskingtape. Cut the wire about 1 ½ inches longer than this measurement.If this is your first attempt at building something, you may want to leave4 ” of extra wire on the piece you are working with. This will allow anadditional attempt of the critical portion of construction.
- Remove the center insulation from the bottom 1-inch of twinlead. Strip the insulation off of the bottom section of twin lead (onlythe 1 “). Connect the wire together at this point and solder.
- From the splice you just made at the bottom, measure up about1 ” and remove ½ ” – ¾ ” of insulation from each conductor.This is where we will be attaching the coax.
- From the splice measure up one side 16 ½” . CHECK THE MEASUREMENT TWICE. Cut a gap on this side about ¼” wide. Besure to remove the conductive material from the notch.
- From the splice, re-measure the total length to 54 ” andtrim the top.
- Attach some coax to the opened area of the wire about 1 ¼”from the splice. The shield of the coax MUST connect to the notched side.
- Attach a suitable connector on the end of the coax for your transmitter and GO!
March ’13 – HF antennas for small spaces.
Most of us now get started on VHF with the Tech license, but very shortly afterward we feel the need to talk beyond the line of sight. HF is a GREAT part of the hobby. Radios, even 20 year old radios, have great specs, are solid state, usually have digital read outs and run on 12 Volts. You no longer need to have a table full of gear to have a very capable HF station. But the radio, and power supply are not a big issue. Your enjoyment of HF will be related to how well you hear and how well you are heard and that my friends comes down to ANTENNAS.
Keep in mind that smaller antennas are easy to hide, easy to put up and don’t hear or transmit as well as longer wire antennas. Many of our members use hamsticks or other mobile whips set up on a mount on a balcony or in a window. They do work but are not very efficient. Adding a counterpoise (1/4 wavelength wire on the ground for the band of interest) will greatly help the performance of these mobile whips. Small whips give up bandwidth. You will need some form of antenna tuner for 75 and 40 meters and maybe for 20 meters.
Rick asked me to do a short review of some of the methods used to study for your amateur radio license. I may be biased, but I think a class is by far the best way to do this, because you get the interaction with experienced hams that can help you with those tricky questions that always seem to come up. My philosophy is I would rather teach the student material so they have an understanding of what they need to know, rather than teaching the questions and the right answers to the questions. If you have ever wondered why our classes are spread over several weeks rather than a weekend or even a few weeks, now you know. As for the book, we use the ARRL’s Ham Radio License Manual, while other instructors use Gordon West’s book. Both are good books for the classroom.
For the student who doesn’t want to commit to one night a week for several weeks, there is the occasional weekend class. To put it mildly, this is like trying to take a drink from a fully charged fire hose. It’s a lot of information over two or even one day. I can’t imagine anyone learns much other than the questions and some of the right answers. Weekend courses require advance preparation by the student and a lot of preparation by the instructors. We tried it once and came to the conclusion the students didn’t get much out of it. In looking at the ARRL’s listing of classes, I find fewer and fewer classes being taught over one weekend. I am seeing some taught over a few weekends.
As with everything else these days, the internet is a place many people go to do their studying. ARRL has an on-line Technician class as part of their suite of continuing education courses. This class uses the Ham Radio License Manual, but the student is paired with a mentor, who is there to guide the student through the material and answer questions. There is no set day and time to meet, its all done via email. However, the student does have a set time limit to complete the class. If you have ever done any of the ARRL emergency communications courses, this is the same format, and it does work very well.
I periodically see a prospective ham showing up on some of the radio websites asking where/how they should get started on studying for a ham license. As you can imagine, the answers are as different as can be. Some people point them to the license class lookup section of the ARRL’s website and some are pointed to the multitude of on-line “study” websites. For the most part, these appear to be websites where they fire a bunch of questions at you and keep score. Some of the ones you pay real money for will keep track of your score and keep firing questions from your problem areas until you figure out the right answer by process of elimination. You don’t learn much, other than the questions and the right answer. You often don’t know why it’s the right answer. As you can tell, I am not a fan of these websites. They are fine as a supplement, i.e., a way to get some experience at seeing the questions and getting an idea of how you might do on the real test.
There is at least one class that is taught as a podcast. You can download this week’s class into your ipod or smartphone and listen in to the instructors go through the material. I don’t really know much about them, I don’t know anybody who has ever used one. Again, I don’t know how the student can ask questions to the instructor.
Not all formats work for every student. If you tried one format and it didn’t work, don’t give on on becoming a ham, try another. Getting a license has never been easier with the different study methods out there.
Congrats to all Spring 2013 student class members and welcome to ham radio. Call signs assigned on Friday, May 10, 2013:
- Rima Azzam KC3AOQ
- Joshua Salpeter KC3AON
- Hala Azzam KC3AOP
- Paul Davis KK4RAW
- Patrica Gabaldoni Inurritegul KK4RAV
- Dennis Albrecht KK4RAX
- Maxwell Albrecht KK4RAZ
- John Hucke KK4RBB
- David Cloft KK4RBA
- Thomas Cole KC3AOR
- Bjorn Jemudd KC3AOO
Congrats to all Fall 2012 student class members and welcome to ham radio. We had our most successful VE session in years last night! 15 candidates without licenses became 12 Technicians and 3 Generals! Best of all, Ryan - 8 years old – is our youngest Tech ever. Thanks to all the VEs who helped and our treasurer W9TCE. VEs were: KA4GFY, N4ASX, KJ4FUU, KI4MWP, N4CWP, N8IK
Groves, Jeffery C KK4NMN
Watson, Charles B KK4NMO
Dundzila, Tomas A KK4NMP
Klee, Ryan R KK4NMQ
Klee, Shannon N KK4NMR
McGhee, Timothy KK4NMS
Drake, Sara K KK4NMT
Jorjorian, Adam D KK4NMU
Ruggieri, James A KK4NMV
Summers, Matthew KK4NMW
Gregor, Jeanne L KB3ZTE
Weston, Ian P KB3ZTF
Toth, David C KB3ZTG
Mann, Christopher E KB3ZTH
Popiolek, Marie D KK6BKG
Congratulations to new ham radio operators and upgrade licensees of Spring 2012 FCC training classes/testing session!
Marshall DeBerry KI4MWP Club President and other members of the Alexandria Radio Club extend their congratulations to newly licensed members and instructors effective May 31, 2012:
Name Call sign New class
Vernon Olson KK4JQM Technician
Mathew A. Kirleis KK4JQN Technician
Dwight A. Nichols KK4JQO Technician
Paul L. Diaz K4JQP Technician
David M. Wilburn KK4JQQ General
Edward J. Bradshaw KK4JQR General
Donghai Yu KB3YUN Technician
James G. Kincheloe KL3IA General
Matthew W. Genack KI4STB Extra
W4HFH ARC sponsors first Newbies On The Air (NOTA) Day – August 2011
Jeremy – KF7IJZ, suggested that ARC sponsor an open event that would help get new hams comfortable with operating amateur equipment on the air. On a beautiful sunny day in Ben Brenman Park, eleven individuals turned out to explore what ham radio can offer. All had a great time, and many suggested that we continue to offer these types of “mini-field day” sessions throughout the year.
2013 FIELD DAY EVENT – by Jeremy KF7IJZ of ARC
FIELD DAY 2013 – JACK Hranicky K5OTZ
This year’s Field Day was a success with 42 people signing in which was a 30% increase over last year. Saturday’s weather was fine; however, Mother Nature was not kind to us on Sunday with rain. This caused us to shut down early. Propagation and the noise level made getting started Saturday slow, but things improved. Several stations worked all night with 40 meters being our best station with over 200 contacts.
We had new hams getting on HF for the first time; many other club members worked our 5A field day status stations. We had ups and downs with antennas, but they served us well, including Jeremy’s configuration-they worked as his station was the high scorer this year. The 40-meter station was operated entirely on solar power charging batteries. Also, this year’s field day’s station/antenna arrangement caused very little interference among radios.
The band captains were KJ4FUU (TOM) who worked 10 meters, KA4FGY (Rich) and N4ASX (Rick) worked 75 meters, KV3W (Jay) worked 15 meters, N4CWP (Harry) worked 20 meters, KF7IJZ (Jeremy) handled 40 meters, and KI4D (Don) handled 6 meters. We got all kinds of bonus points, official visitors (Councilwoman Dell Pepper w/husband), press releases, down loaded an ARRL bulletin, message to ARRL section headquarters, kids operating radios, PR desk, and we (Rick) are working on our total score. And, we even have a video by Jeremy which will be up on our website.
We had 42 people for Saturday’s evening meal…great barbeque. Ted (W9TCE) kept us supplied with refreshing lemonade. Field Day is one of our biggest activities which was demonstrated by the high turnout by the club.
2012 FIELD DAY EVENT – by Jeremy KF7IJZ of ARC
The Alexandria Radio Club had a great annual Field Day (FD) on June 23 and 24, 2012. Weather was perfect. However, propagation was not our friend. For example, Don (KI4D) did not hear a single 6 meter station. Overall, our FD contacts were down from last year, but we proved that the Club can set up eight working stations and operate them for 24 hours. This was made possible by Band Captains (K5OTZ, N4CWP, KA4GFY, KF7IJZ, KV3W, KI4D, N8IK, and KF4BBT) who set up their stations…lot of great work went into them.
- Thanks to Stephanie Adamy’s great effort, the FD food was super. Many thanks to her.
- Jeremy (KF7IJZ ) set up a totally independent 10-15 meter station operating only on solar power
- We did two radio ARRL bulletins for points
- Both days we had Cub Scouts working radios
- We had first-timers on HF
- We had newly licensed hams set up the Got-to-Get on the Air station
- We had a variety of antennas (most worked very well)
- We had 30 people attend, most worked a band station)
- As with last year, the 20 meter station worked the league
- We worked stations from Hawaii to Serbia, even Puerto Rico
- We had several stations operating the entire 24 hours
- We had two CW stations bringing in contacts
- We had a PSK station bringing digital calls
- We had newspaper coverage
- We had an educational table for the public, even the Alex police stopped by
- And, we had a great time doing RADIO.
Thanks to Roy Wright (K4AXQ) our Webmaster for keeping FD information current on our webpage. Major lesson-learned – we need to do a better job in our antenna set-ups and placements.
Many THANKS to all that made this a great Field Day for 2012.
Jack Hranicky - K5OTZ
Field Day Chairman (now retired)
Club President Marshall DeBerry reported 2012 Field Day activity by participating club members at Armistead Booth park, Alexandria, VA
|The following signed into the 2012 Field Day: KJ4FUU (Tom) KI4MWP (Marshall) KI4MWQ (Randy) N8IK (Ian) K5OTZ (Jack) KI4D (Don) KK4CKI (Yeeleng) AJ4YZ (Mitch) WA7LB (Larry) WA7NB (Art) W9TCE (Ted) KF4BBT (Kevin) KI4BXU (Erik) KV3W (Jay) KJ4UYH (Joe) N4CWP (Harry) K4RKB (Bob) N2KFA (Pete) KI4LFG (Nicholas) K6CLM (Cameron) KK4JOM (Vern) AF4ZV (Ken) KK4JOR (Ed) K4GOR (Greg with David) KA4GFY (Rich) KD4FBT (Art) KK4JQQ (Dave) KI4QNG (Sandee) KK4CBL (Larry) KF7IJZ (Jeremy) Visitors – Tim McGhee and Heath Wells|
FIELD DAY is an annual amateur radio exercise, widely sponsored by IARU regions and member organizations, encouraging emergency communications preparedness among amateur radio operators. In the United States, it is typically the largest single emergency preparedness exercise in the country, with over 30,000 operators participating each year.
Public Service Communications provided by Alexandria Radio Club at Bull Run 50K race on April 14th 2012 – Photo credit ARC member Don – KI4D
Club President Marshall DeBerry reported this ARC public service activity by participating club members at Hemlock Overlook in Bull Run, Virginia.
The Virginia QSO Party – March 17 & 18, 2012 – ARC Members are challenged…
in a little expedition to Barboursville, Virginia in the county of Orange to build county scoring contacts for W4HFH club submission. President Marshall DeBerry reported the weather was great and the Virginia countryside was beautiful, with early spring making an appearance. Preliminary scoring indicates we scored better than our 2011 expedition to Buckingham county despite changes to the operating times and so-so propagation.
Jeremy – KF7IJZ Journey in Virginia QSO Party of 2011
Alexandria Radio Club Field Day – June 25-26, 2011
FIELD DAY is an annual amateur radio exercise, widely sponsored by IARU regions and member organizations, encouraging emergency communications preparedness among amateur radio operators. In the United States, it is typically the largest single emergency preparedness exercise in the country, with over 30,000 operators participating each year.
Click Here for a 2011 Pre-Planning Video of ARC approved site by City of Alexandria.
ALEXANDRIA TIMES ARTICLE -
“Alexandria radio operators fight communication voids with frequency” by Danielle Douez Monday 27 June 2011
Portable Solar Power – by Jeremy KF7IJZ of ARC-2012
This is the slide show and audio from a presentation I gave at the August 2012 Alexandria Radio Club meeting. This presentation is based on information I have gathered by researching, experimenting with, and building portable solar powered generators of various types primarily for Ham Radio use. I am BY NO MEANS an expert!
D-STAR Slide/Audio Presentation by Mark Braunstein – WA4KFZ
D-STAR advantage is ability to direct traffic to multiple operators, digital and packetized at the source, a 2400 bps audio input with 1200 bps of error correction and 1200 bps digital channel for GPS or other digital transmissions; uses spectrum more efficiently than FM signal. 1.2GHz system both digital voice and a separate 128KBps digital channel as a high power wireless router; hot spots, DV Dongles and some other developments.