THE LOCAL OSCILLATOR - May 2009 NOTE: An HTML version is available at www.mvrc.qzxservices.com. A pdf file of the web edition is available at http://www.mvrc.qzxservices.com/pdf/LO0906.pdf. It will be easy to print that edition. If you do not have the free pdf reader, you can get it at http://www.adobe.com TABLE OF CONTENTS COMING EVENTS PRESIDENT'S CORNER CLUB NOTES 2009 FIELD DAY BUILDERS GROUP STORAGE BUILDING UPDATE NVIS ANTENNA STUFF TREASURER'S REPORT OFFICERS JOIN THE CLUB COMING EVENTS Sun Slow CW net 3.575 MHz 3:30PM Sun CW net 3.575 MHz 4:00PM M-F 6 m FM net 52.540 6:00AM Mon WTRA Swap net 146.88 8:00PM Wed Net 146.64 6:45PM MWF Informal get together Wal-Mart W (Valley) 10 AM TTH Informal get together Wal-Mart E (Walton) 10 AM June 6 Breakfast 8 AM Club House June 6 Business meeting 9 AM Club House June 10 Board Meeting 7 PM Club House June 16 Buiders Group 7 PM Club House June 27 Field Day noon Club House August 14-15 Duke City Hamfest (Albuquerque, NM) Sept 5 Alamogordo Hamfest (Alamogordo, NM) October 3 Pecos Valley ARC Swapfest (Roswell, NM) PRESIDENT'S CORNER KC5HFJ The usual breakfast and business meeting will be held June 6. CLUB NOTES KD5SSJ None received FIELD DAY As far as is known now there will be an informal field day at the club house. Some people have expressed an interest in operating most of the night as well as during the day. There might be more information on the n5bl.org web site. There might be food at 6 PM. BUILDERS GROUP KD5SSJ At the last meeting we discussed what to do next. A lot of ideas were kicked around. Eventually, there seemed to be interest in a couple of things, QRSS (very slow speed CW used for weak signal work) and instrumentation for the shack (field strength meter, power and voltage meters, etc). After more discussion, a project that might serve all of these in some way or another, microprocessors. Finally, some specifics were discussed and a decision to adopt the Arduino http://www.arduino.cc/ as a platform to use for teaching and experimentation. I was first introduced to the Arduino at the Austin SummerFest (hamfest) almost three years ago. One fellow in particular was so excited about the project that he purchased a bunch of kits and was giving them away. We did a little trading, one of my solder paste syringes for one of his Arduino kits. I came home and built it and played a little bit but I really didn't do much else with it at the time (I had several other microprocessors to play with). The MAKE Magazine regularly features articles and projects based on the Arduino. There are now many variations of the basic hardware but the firmware development tools have become more sophisticated and easier to use. Lots of example projects and resources are available, and best of all it's almost free. There will be those that want to get fully involved in this project and you are going to end up buying some hardware, for those that are interested in seeing what you can do we have a couple of demonstrations that will hopefully let you see it in action. Think of it as a Ham related Adult Education program with no tuition, no outrageous text books and if you want one of your very own Arduino boards to experiment with, a very modest lab fee, $50 to $100, and everybody learns something. I am not proposing that the Builders Group become all Arduino all the time but we will learn enough about it to setup a project and know how and where to proceed. How does this tie into QRSS for instance? AA5CK http://www.aa5ck.com/iduino.html has some documentation of how he is using the Arduino and some of his weak signal work. In this discussion he mentions a couple of local Hams WA5DJJ, Dave Hassall and KC7VHS, Perry Steinman. One graphic shows WA5DJJ received with perfect copy in Australia using only 900mW. Dave does this routinely and also Europe. On Tuesday June 2 there was demonstrated a DDS based QRSS controller based on one of my kit boards and the Arduino microprocessor board. In case you're not familiar with the acronyms, DDS stands for Direct Digital Synthesizer which can produces a sine wave from below audio frequencies and continuously through 6m (DC to 60MHz) and QRSS weak signal very slow CW beacon. STORAGE BUILDING UPDATE AD5LJ We had another work day on Saturday 17 May. We managed to complete painting the outside walls and the front doors. The building is finished except for some caulking and construction of shelves inside. I would like to thank the following for their outstanding work: George KD5OHA, Ron KE5KLK, Al K7ICW and Dennis KB5TPV. NVIS ANTENNA STUFF KI5FJ Shakespeare, the entertainer, was once quoted by Marconi, the radioman, as stating "A good aerial is one of the most important things in life." Well maybe not! In any case, I was asked to prepare some How To Build instructions for a Near Vertical Incidence Skywave (NVIS) aerial or antenna. What follows is more like a story than simple instructions. The first consideration is how much land is available. A 100 Ft by 20 Ft would accommodate a Marconi type antenna, a design similar to the new 80,75,60,40 & 30 Meter antenna at the MVRC club house.The Marconi type is a ground mounted and fed antenna. This could be an inverted L design.Horizontal wires low to the ground 10 to 15 Ft are adequate. B. 200 Ft by 20 Ft would accommodate ahertz type of antenna for the same bands.The hertz type is a dipole design. The same 10 to 15 Ft height is desired. C. 70 Ft by 70 Ft would accommodate a low to the ground horizontal loop Antenna. The second consideration is how much cash is available. A. Unlimited finances could allow a remote automatic antenna matching box (ATU).This ATU and a single non-resonate wire can be matched for the NVIS bands. B. Very limited finances, a two band, specific frequency per band solution is easy. C. Somewhat limited finances, and the builder desires to cover all NVIS bands a Multi-wire resonant system is a good approach. The third consideration is impedance matching.An impedance matching device either internal to the transceiver or an in the shack external (Manual or automatic tuning) is a necessity! The club’s TS-570D transceiver has an internal ATU. I was prepared to back this up with an home brew manual ATU if necessary. Construction of the inverted L NVIS antenna started at my home QTH.It was designed to fit the available space at the clubhouse. 15 ft high wires, high enough to clear the shed, would fit in East-West plot of 100 ft by 20 ft. I recycled a 2-inch by 7 ft length of steel pipe. It was previously encased with 18 by 10 inches of concrete. Adding 130 lbs of concrete mix to the previous very substantial concrete, pipe combination. This resulted in a very stable support. The support is located 60 Ft from the east end of the shed. The mid-way support was to be the east end of the shed. Reinforcing the shed wall with 1 by 3 inch wood allowed for ¾ inch pipe flanges to be very secure. Standoff brackets completed the support process. The end support was to be suspended from a previously used hook on our short power pole. The next phase was more fun, it was technical, no digging or drilling required. Using the concept that the longer the horizontal wire, the more signal sent or received drove the design. Radiators of 0.25 or 0.75 wavelengths (wl) long would be a good match to a 50-Ohm cable. Sufficient number of buried radials would form the other half (image) needed for an efficient antenna. The formula 234 divided by Mega-Hertz equals the length in feet for a 0.25 wavelength radiator. Simply 3 times is 0.75 wavelengths. This longer length was my design goal. The 80-75 Meter 0.25 wl wires took up half of the available space. Using a linear loading coil to extend them would not significantly extend the wire compared to the required coil size. The 60 Meter radiator is a 0.75 wl, coil loaded. The 40 and 30 Meter radiators are 0.75 wl no coil loading. The wires are spaced at least 29 inches apart. The next phase was not fun, more digging! I buried nearly 80 Ft of ¾ inch plastic electrical conduit. This conduit protects the RG-8X coax cable from the shack to the feed point. Then I dug fifteen 20 Ft long trenches for the radials. Then I dug a 40 Ft trench for the long radial that extends to the East End of the shed. The next phase was relatively simple. I transported the previously constructed antenna masts and other parts from my yard. The two 15 Ft masts consist of a 10 Ft and a 5 Ft length of typical TV antenna masts. The two 15 Ft cross arms are 1 Inch schedule 40 PVC reinforced with wooden dowels. The end support is a 7 ft length of 1 Inch reinforced PVC pipe. Constructing the masts and pruning the wire lengths is too exhausting to relive. As I had hoped, the antenna worked as designed. Very favorable signal reports were received on 75 and 40 meters. On-the-air analysis of 60 and 30 Meters is pending. I will be glad to share more information with anyone desiring to build a NVIS antenna. MAY TREASURER'S REPORT KI5FJ INCOME BUDGET ACTUAL YTD Bean Feed Food 400.00 375.00 Breakfast & Drinks 600.00 398 Contributions 250.00 135.99 Dues 2000.00 1855 Education Classes 850.00 220.00 Equip Sales & Raffles 1845.00 2053 Bank Interest 30.00 Other 0.00 TOTAL 5975.00 5036.99 EXPENSES BUDGET ACTUAL YTD Bean Feed 300.00 296.72 Breakfast & Drinks 400.00 79.76 Clubhouse 400.00 43.84 Education Classes 850.00 249.31 Field Day 150.00 Insurance 1000.00 Misc 100.00 121.15 NM Emergency Fee 30.00 30.00 NM Tax Exempt Fee 10.00 10.00 PO Box Rent 60.00 Postage 100.00 President’s Fund 75.00 78.96 Property Tax 800.00 Repeater Maintenance 600.00 212.91 Electricity 450.00 196.37 Propane 500.00 39.29 Water 150.00 84.47 TOTAL 5975.00 1442.78 AS OF 31 May 2009 INCOME 5036.99 EXPENSES 1442.78 NET +3594.21 OFFICERS Pres Perry Welch KC5HFJ 373-9171 Perrywelch@hotmail.com VPr Cash Olsen KD5SSJ 382-1917 kd5ssj@arrl.net Sec Jack Lemons N5PK 644-7207 jack_N5PK@hotmail.com Treasurer Joe Ostrowski ki5jf@arrl.net BOARD Communications Henry Schotzko AD5FE 526-1922 schotzko@comcast.net Education Special Events Kevin McNelis K5KMC 571-7326 kmcnelis@nmsu.edu Newsletter Alex Burr K5XY 522-2528 k5xy@arrl.net Clubhouse Bob Bennett AD5LJ 382-0148 rpbennett1@comcast.net Repeaters Robert Truitt KE5OFK 649-4173 robtruitt@zianet.com JOIN THE CLUB To join the Mesilla Valley Radio Club, renew your membership, or to support the repeaters, please complete the form below and send it with dues ($35 single, $45 family per year) to: Treasurer, MVRC, Box 1443, Las Cruces, NM 88004. Name: Address: Call: Class of License: Phone: E-Mail Address: ARRL Member? Yes? No?