Obtaining this designation was really intended to be a capstone on top of all of LETARC’s 25th anniversary events last year, but it got delayed a few months into this year.

This is a big milestone for the club and we wish to express our gratitude to Todd Hoover (N5TJH) and our Secretary/Treasurer, Terry Johnson (KG5WO) for their perseverance in putting together all the necessary documentation and answering the IRS’s questions.

Jerry took the time to explain how this was accomplished by publishing a document that goes into the details of multiplexing. Below is a link to his document. You will need Adobe Reader or Adobe Reader web browser plugin to view it.

Multiplexing Repeaters

Again… many thanks to Jerry and Jim!

• Technician – April 27, 2013
• General – May 25, 2013
• Extra – June 29, 2013

All classes will be held on Saturdays and will run all-day 8:00AM-5:00PM with a one hour lunch. Classes will be held at LeTourneau University. Check the LETARC web site calendar for exact locations on campus and directions, as those may change depending on classroom availability.

The classes are free of charge and will not require a book. Although, many may wish to purchase the license level study book from ARRL or the W5YI group ahead of time… but it is not necessary.

You MUST RSVP for these classes to ensure we have enough space. There is a sign-up form for the classes at http://bit.ly/LETARC-RSVP . You can sign-up for multiple classes if you wish. Just follow the instructions on the form.

First, find the published loss for your feedline at the frequency of interest.  You can use manufacturer’s data, or general data from a source such as the ARRL Antenna Book.

Then, get an SWR reading at the input, (transmitter end), of the feedline.  Use chart, “SWR@FeedpointChart”, to determine the SWR at the antenna input.  Plot your measured SWR on the bottom edge of the chart, trace up to a point in the curved lines that reflects the published feedline loss you found in the first step.  Trace to the left to find the SWR at the antenna feedpoint.  This is a rough approximation, but quite accurate enough for our purposes at HF frequencies.

Then, using the chart, “AdditionalLossChart”, find again the published loss on the bottom of the chart, and trace upward to the point in the curved lines that reflects the SWR at the  antenna, found in the previous step.  Trace to the left from that point and find the additional loss due to this SWR.

Add this additional loss figure to the published loss figure for your feedline.  This should closely approximate your total loss in the antenna system.

The charts can be found here:

http://letarc.org/main/wp-content/uploads/2013/01/SWR@FeedpointChart.pdf

http://letarc.org/main/wp-content/uploads/2013/01/AdditionalLossChart.pdf

The QST article, on which the program was based, is “What Does Your SWR Cost You?”, by Stan Gibilisco, W1GV.  It is in the January 1979 edition.

Tom Wilbeck – N5KGN

Tom Wilbeck – N5KGN

I lost two of my ham radio “heroes” this year.  I guess we always think that people we admire will last forever, much as I did about my father, who was suddenly taken from me in 1964.  I was once again shocked to learn that both of these fine gentlemen and ham radio operators became SKs.

The ham radio men to whom I refer were Bob Shrader, W6BNB, and Walt Maxwell, W2DU.  I was fortunate to have had personal contact with Shrader, but sadly was never able to have a one-on-one discussion with Maxwell, though I had made attempts.

Bob Shrader

Mr. Shrader received his ham radio license in 1932.  In 1933, went to sea in the Merchant Marine as a radio operator and sailed worldwide until 1939, when he became a deputy sheriff.  While in that service, he was a radio operator and patrol deputy.  In those days, even law enforcement departments had CW operators!  He left there for a stint as an instructor at the Merchant Marine Academy in New York where he taught radio and electricity subjects.  He returned to the Sheriff’s Office in 1945.  In 1946, he began teaching at Central Trade School, later known as Laney College.  In 1969, he retired from teaching and became a volunteer fireman.  He later became Chief of that department and later, Director of another fire department.

Bob wrote Electronic Communications, in 1959, as a textbook for trade school and college level electronics courses.  He also wrote many QST articles and was still writing QST articles in 2010.  After his retirement from teaching, he also wrote a book, Amateur Radio, Theory and Practice.

I first became familiar with Mr. Shrader when I obtained a copy of the fifth edition of, Electronic Communications, which was published in 1985.  While I was part-time teaching at Kilgore College, a fellow instructor gave me a stack of text books.  Some were old editions that the college had previously used and some were samples from publishing houses.  When I first cracked the cover of this book, I knew it would be a reference for many years to come.  It covered radio in its many forms, including Amateur and Marine; radar; telephone systems, both wired and wireless; and television.  It will be unlikely that I would ever part with it.

A few years ago, I emailed Bob and thanked him for writing the book.  He was very cordial and appreciative.  We corresponded several times before his becoming an SK in April.

Walt Maxwell

Walt Maxwell was born in 1919 in Florida.  His father was a ham and moved the family to Michigan where Walt grew up.  Walt was first interested in radio in 1922 while watching his father build equipment.  Walt built his first receiver at age 6 with his father’s help.  Walt graduated from college with a degree in Math and Physics.  He then dabbled in music and theatre sound systems and worked at a radio station.  He received his first callsign in about 1940.

During WWII, Walt worked for the FCC.  He worked on monitoring stations until 1944, and was then an electronics instructor in the US Navy.  All the while, Walt had been playing music in ‘big bands’, a habit he continued for most of his life.

After leaving the Navy in 1946, and having his own business, he served as chief engineer at a broadcast station until 1949.  Then he joined RCA Laboratories as an engineer.  In 1960, he was in charge of the antenna laboratory at Astro-Electronics Division of RCA.  While there, he designed and tested many successful antennas used on satellites, including the ECHO and TIROS series of birds, as well many other space related projects.  He retired from RCA in 1980.  After retirement, Walt maintained an active life of consulting, researching, testing and writing.

Where I first became aware of Mr. Maxwell were some QST articles in which he was quoted, and some ‘letters to the editor’ which he wrote.  I purchased one of his books, Reflections II, Transmission Lines and Antennas.  While much of the book was over my head on the first read, going through it again and again made it clearer.  His writings answered many of my questions about things I had experienced with antenna systems that just didn’t square up with popular opinion.

Aside from his books, which in addition to the above included an earlier edition of Reflections II, and and a later work, Reflections III, Walt also wrote a great many articles published in QST.  He was always a bit controversial, as he had very definite beliefs and sought to “straighten out” anyone who didn’t see it his way.  The thing about Maxwell was, though, that he could always back up his beliefs with actual laboratory findings or with multiple authoritative sources that agreed.  While I really don’t honestly believe that Walt was right 100% of the time on the subject of antenna systems, I think he was on the most important ones.  And those seem to be where he always drew a firestorm.  Whatever, he convinced me that, with a non-resonant antenna and a transmatch, you can have an effective radio station that is capable of operating in many parts of the Amateur RF spectrum.

Walt Maxwell became a Silent Key at his home in Florida in July of this year.

In my opinion, Amateur Radio lost two heavyweights of wisdom and knowledge.  I hope I can somehow reflect the contributions they have made to the hobby and my enjoyment of it.

http://letarc.org/main/wp-content/uploads/2012/08/RF-Exposure-Guidelines-Talk.pdf

Note:  The link to the first Power Density Calculator should be:

http://hitlink.com/power_density.htm

It is not written correctly in the document.  My apologies for that error.

Tom – N5KGN

The series, A Beginner’s Guide to Modeling with NEC, covers the use of two popular antenna modeling programs used by amateurs.  One is NEC-Win Plus, and the other is EZNEC.  The articles explain the difference between the two programs and how to use the basic functions of each.  The articles, published in QST in 2000 and 2001, were written by L. B. Cebik (SK), a well-known authority on antennas and many other amateur radio topics.  While the manual that comes with EZNEC is very complete, these articles speak in a more descriptive, less engineering, language.
The articles are easily available at the ARRL website, or on the ARRL Periodicals CD-ROMs:
A Beginner’s Guide to Modeling with NEC
Part 1  “Getting Settled and Getting Started”                        QST November 2000  pg 34
Part 2  “The Ins and Outs of Modeling”                                 QST December 2000  pg 40
Part 3  “Sources, Grounds and Sweeps”                              QST January 2001  pg 44
Part 4  “Loads, Transmission Lines, Tests and Limitations”  QST February 2001  pg 31

Another article that will shed some light on how these programs developed and give some additional information is MININEC: The Other Edge of the Sword, by Roy Lewallen, W7EL.  Lewallen is the author of EZNEC and its forerunner, ELNEC.  MININEC was an early program that put the power of antenna modeling in the hands of the layman, rather than RF engineers.

Tom – N5KGN

We will be having a special open house event at the Red Cross on May 19th from 9:00AM to 11:30AM, in lieu of of our normal monthly meeting, to celebrate this momentous occasion. It is very fitting that we will also be showcasing our newly renovated radio room to the community at this same event.

To help us celebrate, Walt Mayfield – KE5SOO, ARRL’s North Texas Section manager, will be in attendance. We also hope some of our local city officials, emergency communications served agency representatives, and representatives from other area clubs will be in attendance.

Please stop by, enjoy some refreshments, and help us celebrate!!

For years, Kenwood has kind of dominated the APRS market with the D710 mobile and the D72A handheld and their predecessors. In fact, I have the D710 as my base VHF/UHF station and a D72A handheld. Both are excellent APRS-capable radios.

Recently, I started looking at replacing the equipment in my vehicle with one radio. One would think that since I already had the Kenwood D710 as a base station, that I would put that radio in my vehicle. That was one of the options I considered. However, I wanted to consider all options.

In investigating the options, I had certain requirements for the radio:

• Dual-band (VHF and UHF), dual receive
• Full APRS capability
• Cross Band Repeat capability
• Should be able to re-use (to the extent possible) my existing mounts for the control head and radio.
• GPS should either come with the radio or be a fairly inexpensive optional add-on.
• Minimize  the number of wires being run between the radio (mounted in the rear of the vehicle) and the control head (mounted on the dash).
• D-STAR (thus DPRS) was an option, if the additional cost was not excessive.

In looking at the above requirements, this narrowed the options down to three radios:

Alinco also makes an APRS-capable radio. But, I guess I have never been a real fan of Alinco products… sorry Alinco fans.

Narrowing the Field

Almost immediately, the ICOM was ruled out, because in order to get DPRS capability, one has to buy an additional $300 module to allow digital operations on the D-STAR network. The add-on does come with a GPS with a magnetized antenna. However, the antenna cannot be mounted outside the vehicle (not sure what ICOM was  thinking on this one). One additional benefit would be D-STAR communications, but I could not justify the additional cost, which would push the investment to around $1000.

Overall, both the Kenwood and the Yaesu have almost identical capabilities, with very few exceptions. For example, the Yaesu does not digipeat and the Kenwood does. Both radios do packet and both do cross band repeat. After looking at the specs in more detail, it appeared to me that the Kenwood is more suitable for both base and mobile operations, whereas the Yaesu is geared more to mobile application.

GPS Options

One of the things required in an APRS-capable mobile in a mobile operation is a GPS, in addition to the radio. Kenwood does not have a GPS option itself, but relies on third party manufacturers, such as Greenlight Labs, Byonics, or Garmin. Yaesu has two options of its own, one of which installs in the back of the control head. Both the Kenwood/Greenlight Labs and the Yaesu FGPS-1 options eliminate the need for additional cables being run within the vehicle. However, the cost differential between the Greenlight Labs GPS and the Yaesu FGPS-1 is significant. Greenlight Labs GPS is $130 and Yaesu FGPS-1 is $68.

Control Head Mounting

WIth my Yaesu FT-8900, I had a Lido LM-600 Lo-Boy dash mount. I highly recommend Lido Mount solutions at http://www.lidomounts.com. What I really wanted was to try and re-use this mounting solution if I possibly could. The Kenwood has a very unusual mounting bracket that attaches to the control head that virtually makes it useless with other mounting options. It’s not that it is not possible, but it would be very inflexible. The mounting adapter is meant for Kenwood mounting options only. Lido has very few options for the Kenwood, I think for this very reason. The Yaesu comes with a suction cup mount that attaches to the camera tripod style screw thread in the control head. Lido has made a very specific attachment piece for the Yaesu FTM-350 that works with its various mounting options that is a ball and socket affair.

Microphone Connections

I continue to be amazed at the number of radios that put the microphone connection on the radio itself and not the control head (or at least have it as an option at the control head). Both the Kenwood and the ICOM only have the microphone connection at the radio. The Yaesu has connections at both locations. If one has the radio in a location that is not near the control head, this is yet another cable that must be run within the vehicle.

GPS Connections

All three radios approached this differently.

ICOM is connected at the radio. However, you can’t mount the magnetized antenna outside. The trick with this is finding a metal surface within the vehicle with everything being plastic these days.

Both the Kenwood and the Yaesu have options that eliminate the need for additional cables, as noted above (attached or built-in to the control head).

Control Head Connections

All three radios use an RJ-45 cable for connecting the control head to the radio. So, this is a given in each radio option. Only the ICOM allows you to attach the control head to the radio.

The Choice

After carefully weighing all the requirements and capabilities, I chose the Yaesu FTM-350AR. While not particularly bearing on the choice, the Yaesu had some other capabilities the others did not. For example, the Yaesu has Bluetooth microphone options, more screen color choices, and a voice recording option (I believe the Kenwood also has the voice recording option).

In working with APRS on this radio, full APRS capability (popups, messaging, etc.) requires the dedication of one side of the radio to the APRS frequency. If one is doing tracking beaconing only, APRS can be placed in the background and both sides of the radio can be used for non-APRS use. The radio will momentarily interrupt to accomplish the beacon. If placing the radio in cross band repeat mode, one must first turn off the APRS modem/TNC via the menu system.

Conclusions

With very few exceptions, the Yaesu FTM-350AR is on par with the Kenwood TM-D710A in terms of functionality and, in come cases, has additional options the Kenwood does not, for true mobile operations. Yaesu has a better mounting attachment arrangement that is more standard, allowing other manufacturers to develop more flexible control head mounting options. Yaesu also has figured out that one needs to have flexible microphone connection options.

Overall, I have been very impressed with the capabilities of the Yaesu FTM-350AR. After more extended use, I may come back and give an update at a future date.

Gary Lewis – WG5L

The club’s new repeater is on the air at its new location in the Spring Hill area!

Many thanks to all who helped make this happen over the holidays, so we could have it operational for the new year!

Pictures from First Work Day – Removal of old antennas and installation of new antenna

Tom Wilbeck - N5KGN on Tower	Jim Rogers - N5VGQ, Rod Bartlett - N8QVR, & Dean Patterson - KE5AVH assembling antenna (picture taken by Jim Quinn - AJ1MQ)

Click here to view the video on YouTube.

Pictures from Second Work Day – Grounding rods, pad and cabinet installation, and electrical prep

Click here to view the video on YouTube.

Pictures from Third Work Day – Installation of repeater equipment and test

Jim Rogers - N5VGQ installing repeater components	Terry Johnson - KG5WO, Tim O'Sullivan - K1TGO, Dean Patterson - KE5AVH, Gary Lewis - WG5L, Rod Bartlett - N8QVR, taking a break (photo taken by Tom Wilbeck - N5KGN)

Our club net on Wednesday nights at 8:30PM are now being held on the repeater.

Join us on the net!