Columbia Amateur Radio Association Newsletter May, 2002

Transcription

1 Columbia Amateur Radio Association Newsletter May, 2002 May 28, 2002 Lindenblad Antennas Pete Young, K3IN + Rol Anders, K3RA This Month at Prez Sez Picnic...3 Repeater Pix...3 Calendar...8 Club Info...9 Meeting May 28 7:30 PM Room 401, Gateway Center Pete discovered Lindenblad antennas while working on a small R&D project for Woods Hole Oceanographic Institute and NASA involving the design of science data collection ocean buoys a few years ago. The idea was to have Woods Hole design and install scientific sensors on a buoy, and for Pete s two man company to design and build a computer and satellite RF communications system for the buoy to use to relay the data via a LEO satellite that was identical in every respect to an amateur mode J PACSAT satellite, except for frequency its uplink was on 139MHz and its downlink on 435MHz. As the RF guy, Pete looked at various antennas adapted from ham manufacturers, and realized that the antenna pattern for Lindenblads was better suited for satellite work than any of the other omni antennas on the market. Pete will show you the antenna's radiation pattern and show why it is so well suited for satellite work, then show you the essential elements that make up a Lindenblad and how they go together. Finally, he'll talk about the people who have done antenna modeling on these antennas, and their experiences, and provide a suggested reading list, where you can learn more about them. In addition to Pete s presentation, Rol Anders, K3RA, will give you the scoop on our plans for this year s. We re going to be in Clarksville this year and there will be plenty of opportunity for you to operate. We re looking for volunteers to help with set up and tear down, too. We ll have a sign up list at the meeting.

2 Prez Sez We ve had three public service events in the last few weeks, and I d like to give a warm and well deserved thank you to those who participated: MS Walk April 21, 2002 W8AJR NG3B K3BAZ K3BLB K3EF KF3O N3OY K3UOD W1TRT March of Dimes Walk May 5, 2002 WB7ADC W8AJR NG3B K3BAZ N3FKQ W3GJN W0NQW N3OY K3RER W1TRT K3UOD Columbia Triathlon May 19, 2002 N3AC WB7ADC W8AJR NG3B K3BAZ K3EF KC3EV W3GJN N3LDC W0NQW KF3O N3OY WA1QAA N3RER W1TRT K3UOD Special thanks go to Ed, K3EF, who coordinated our participation in the MS Walk and the Triathlon, and to Dan, N3LDC, who coordinated our efforts with the March of Dimes Walk. If you are associated with a charitable group who puts on a public event that would benefit from amateur radio communications, please bring the event to our attention. would be happy to meet with the organizers to see if there is a useful role for us. We ve got two events upcoming in the near future that would benefit from your participation (and vice versa, eh?). June 21, 22, and 23, 2002 We ll be at Clarksville Elementary, on Rt. 108 about a mile north of Rt. 32, this year. As in our past collaborations with the Potomac Valley Radio Club (PVRC), we ll have at least 20 to 25 HF stations on the air, plus VHF, UHF, and satellite stations. There will also be a Get On The Air station to give new hams and those with no contest experience an opportunity to try it at their own pace. Set up starts on Friday afternoon, June 21, beginning about 2:00 pm and formal contest operation will start Saturday afternoon and run until Sunday afternoon. We need volunteers to help with set up and tear down and to help man all of the stations. Helping with the towers and antennas is a great way to see a variety of equipment up close and to learn how it s put together from the real pros in the hobby. There will be many openings for those who would like to try their hand at CW, phone, or the digital modes of communication. Columbia Amateur Radio Association Newsletter: May,

3 Picnic July 23, 2002 Our July meeting will be a picnic meeting again this year, probably to be held at a pavilion in Centennial Park. We need a couple of volunteers to help round up charcoal, plates, cups, and utensils, and to keep a tally of the food folks are bringing so that we can be sure that all of the bases are covered. If you re willing to help, please give me (W8AJR) a call. If two or three folks get together on this, there won t be much of a load on anyone. equipment in the shelter is Howard County s existing VHF/UHV Police, Fire, and Public Works voice and data system, plus their new 800 MHz trunked system. Our equipment will move to the back of the shelter after the older county VHF and UHF gear is removed. Here s a close up of the repeater cabinet. On top, just below the meters is the 500 watt final amplifier used by The two rectangular openings are the tube compartments where the conduction cooled final amplifiers are located. Repeaters If a picture is worth 10,000 words, then here s a veritable tome of information on two of our repeaters. The first two pictures show the and repeaters in their cabinet at Jonestown. (This picture was taken before was moved to Timbers at Troy. The repeater cabinet is the second object on the left. The remainder of the The black object below that is the DC power supply for the repeaters. Below the power supply is the duplexer for The white object below the duplexer is the Yaesu Vertex repeater used on An identical repeater for Columbia Amateur Radio Association Newsletter: May,

4 is mounted behind the UHF repeater. The power supply for the final amplifier is out of sight, just below the repeater. The final picture shows the repeater in its new enclosure mounted atop the WBFF tower. At the top is the local monitor and control panel. Beneath the panel is the Yaesu Vertex repeater, which is mounted at the rear of the enclosure. Below the repeater are the duplexer and receiver bandpass cavity filters. There is room in the top of the enclosure for us to add a power amplifier or a link transceiver in the future. Free Tower Do you live in one of those enlightened realms in which amateurs are allowed to have towers? Would you like a free fifty foot tower? If so, please call Dick or Delores McBirney at Help Needed! June Friday Set up Contest Operation Sunday Tear down Picnic 23 July Supplies Food Coordination Can you help? Please contact W8AJR Columbia Amateur Radio Association Newsletter: May,

5 Calendar of Events Sun Mon Tues Wed Thurs Fri Sat M a y Meettiing Sun Mon Tues Wed Thurs Fri Sat 1 J u n e Breakfast at Forest Diner Frederick ARC Hamfest t Laurel VE Meettiing J u l y Sun Mon Tues Wed Thurs Fri Sat Harrisburg ARS Hamfest Breakfast at Forest Diner Laurel VE Columbia Amateur Radio Association Newsletter: May

6 Club Information Repeaters (K3CUJ) / R+ Net repeater. CTCSS: Hz / R+ Open autopatch ( * to activate, # to clear) and direct dial / R CTCSS: Hz / R CTCSS: Hz Mailing Addresses Club Business P.O. Box 911 Newsletter c/o Dave Prestel W8AJR Tanfield Court Columbia, MD Ellicott City, MD dprestel@comcast.net This newsletter is Copyright 2002, Columbia Amateur Radio Association, Inc. Items from this newsletter may be republished only for non-commercial Amateur Radio use; credit must be given to. If you wish to republish material from this newsletter for other purposes, please contact the newsletter editor. Activities Club meeting: the fourth Tuesday of the month at 7:30 p.m., in the Gateway Center, on Columbia Gateway Drive, off of Rt. 175, near I 95. Monitor /R for directions. Meeting room will be posted in the lobby. On-the-air RACES / ARES net: /R at 7:30 p.m. on the 1st and 3rd Tuesdays each month. On-the-air RACES exercise: /R at 7:30 p.m. on the 2nd Tuesday each month. breakfast: 9:00 a.m. on the second Saturday of each month, at the Forest Diner, on Rt. 40 across from the Enchanted Forest Shopping Center. If you wish to attend, contact Bob Scarburgh, KC3EV, Executive board meeting: Held monthly, one half hour before the regular meeting. All members are welcome. on the World Wide Web: Visit us at for the latest hot tips and electronic edition of the newsletter. Officers and Chairpersons Officers: President... Dave Prestel... W8AJR... H: dprestel@comcast.net Vice-president... John King... KB3WK... H: kb3wk@arrl.net Secretary... Dan Goulette... N3LDC... H: danjanis@connext.net Treasurer... John Pinkston... W3GJN... H: jpinksto@erols.com Member-at-large... Tim Titus... W1TRT... H: w1trt@aol.com Past President... Bob Scarburgh... KC3EV... H: rscarburgh@aol.com License Trustee... Alan Chedester... N3AC... H: alanc1@juno.com Committee Chairpersons: Elmers... John Pinkston... W3GJN... H: jpinksto@erols.com... Alan Chedester... N3AC... H: alanc1@juno.com John Pinkston... W3GJN... H: jpinksto@erols.com FAR Rep... Tim Titus... W1TRT... H: w1trt@aol.com Hamfest... Randy Krenz... N3HFK... H: randykrenz@erols.com Newsletter... Dave Prestel... W8AJR... H: dprestel@comcast.net Publicity... Vacant Satellite... Ed Cabic... N2EC... H: edcabic@comcast.net Social... Vacant Quartermaster... Vacant Technical... Art Goldman... N3OY... H: artg@comcast.net T-MARC Rep... Dave Prestel... W8AJR... H: dprestel@comcast.net VE Testing... Bob Scarburgh... KC3EV... H: rscarburgh@aol.com Youth Education... Dave Anderson... WA3WZX... H: dranderson@juno.com Youth Group... Vacant ARES / RACES: ARES... Ed Wallace... K3EF... H: k3ef@comcast.net RACES... Mike Carr... WA1QAA... H: bamcc@erols.com Columbia Amateur Radio Association Newsletter: May