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| Monthly Newsletter Dedicated to the Advancement of Amateur Radio November, 1998 |
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THE PRESIDENT'S CORNER
Thanks to Professor Dwight A. Nesmith for a very entertaining presentation. We have his talk on video tape if you missed it or want to see it again. The next meeting will be November 13th at 7:30 p.m. in room 152 Rathbone Hall on the KSU campus. John NØPVT will talk about short-wave listening tricks and experiences. We will also have the election of officers. The nominations from the nominating committee are listed in this newsletter but nominations can also be made from the floor at the meeting. Remember that you have to pay your dues before November 1 to vote. This will probably be our last meeting at KSU. In January we will hold our meeting at the Riley County Red Cross building on Poyntz in Manhattan. Plans for a club station at the Red Cross building are moving along and it should be in operation before the end of the year. There is no Friday night club meeting in December. The December meeting will be a Christmas Party on Saturday, December 12 at 6:30 p.m. at Fred (KØTCS) and Nadine (KØUHF) Stueve's home just west of Wamego. It is a pot luck dinner plus you should bring a $5 unisex gift for exchange. Turkey and ham and drinks will be provided. If you don't want to bring a dish you can give $5 to one of the officers. I don't know the name of the gift exchange process but it's a lot of fun. When your number is drawn you can pick a wrapped gift or take one away from someone else. It gets pretty wild. As usual, non-members and friends are welcome. The XYL's had a nice evening out at Harry's Uptown Restaurant in October. The next XYL evening out will be on Wednesday January 27, 1999 at the Cowboy Cafe on I-70. Our auction in October went real well. MAARS made $242.70 and KSUARC made $349.45. There is a free teletype machine at our house if anyone wants it. |
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NORM'S NOTES
Norm Dillman, NØJCC REMEMBER THAT THE JANUARY MEETING WILL BE AT THE RED CROSS BUILDING. Temporary VHF/UHF link to KC: Thanks to help from Greg, WQØP and equipment from Chuck, AAØRI we were able to communicate with hams at the KC airport from Manhattan on October 8. The occasion was a national convention of the engineering honor society, Tau Beta Pi, held in Manhattan. They wanted to coordinate the transportation of over 300 people. Greg (in Belvue) monitored the 146.79 - repeater near the airport and automatically cross-band repeated on 70 cm simplex to our place on Gehrt Road. We used Chuck's dual band rig to cross-band back to 2-meter simplex to the Holiday. It was an interesting experience and I think we're better prepared for setting up emergency communication links when needed. Club Station at the Red Cross Building: We're moving ahead with a club HF/VHF/UHF station. Several donations or loans of equipment have already been committed and several good ideas have been proposed. The club trustee, Chuck, AAØRI is applying for a club vanity call; either KSØMAN or KSØMHK. |
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SECRETARY'S MINUTES
Lenore Layman, NØTSN
Manhattan Area Amateur Radio Society
The guest speaker for the evening was Dwight Nesmith, "An Anthology of Insignificant Incidents of International Significance." Norm Dillman, NØJCC approached the club with several motions: 1. That the club consider holding our meetings at the Riley County Red Cross Chapter Building on Poyntz starting in January, 1999. The room is smaller than our current meeting room in Rathbone hall but, it will be easier for the public to locate and not require a KSU faculty member to arrange space. Norm noted that to meet in Rathbone the meetings are listed as joint meetings with the KSUARC. Jon Held, NØRYQ made a motion that the club hold its January meeting at the Red Cross Building and if accommodations were comfortable for our needs we would hold our meetings at that location. All were in favor. 2. Chuck Carter, AAØRI will be the MAARS Club Trustee for MAARS HF/VHF/UHF Club Station at the Riley County American Red Cross Building using donated equipment. Norm will supply equipment for one year and volunteer as station manager. The club approved a budget not to exceed $100 for small items like ground rods, etc. A 440 radio will be needed for this location. 3. Chuck, AAØRI will apply for a club vanity call. The club voted on calls and agreed on KSØMAN as first choice and KSØMHK for second choice. All were in favor. A revision to the Standard Operating Procedures shall be made under section Standing Committees - Officers and trustee may authorize emergency repeater repairs up to half the cost of a new repeater. A vote was taken and all were in favor. This allows repairs to be made to the repeater as soon as needed instead of waiting for the next club meeting to vote delaying this further. The cost for repairs for the repeater came to $101.55 and a tone board was purchased for $62.45. A motion to pay for these items was passed. A thank you card was sent to Roger Carrender for his work on our repeater. Dues are to be paid by October 31st in order to vote at the November meeting. Nominating Committee consists of Jon Held, Chuck Carter and David Yoder. If anyone is interested in running for an office, please notify one of the committee members. Christmas party will be on Saturday, December 12. Bring something for pot luck or a $5.00 donation. Start at 6:30 p.m. at Fred and Nadine's house. There will be a $5.00 optional gift exchange. The Christmas party will take the place of our regular scheduled Friday night meeting. XYL - Thursday - October 22 at Harry's on Poyntz 7:00 p.m. Myron passed out registration forms if anyone would like to provide emergency communications for AREA and/or RACES. Please contact Myron Calhoun, WØPBV if you are interested. The next club meeting will be the annual election meeting held on November 13th. |
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REPORT OF THE NOMINATING COMMITTEE
Chuck Carter, AAØRI, Jon Held, NØRYQ, and Dave Yoder, KAØJPM This year's Nominating Committee took the easy way out and renominates the incumbent officers. PRESIDENT: Phyllis Dillman, NØMJB VICE PRES: Henry Bachman, KAØSWM SECRETARY: Lenore Layman, NØTSN TREASURER: Nadine Stueve, KØUHF Nominations will be taken from the floor, and are encouraged. |
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ANTENNA TALK
Jon Held, NØRYQ
SWR What is it and what does it really mean? It's a measure of reflected power. It normally is used to tell us if our antenna and feed line is operating well. It's actually a shortening of the term VSWR, voltage standing wave ratio. It is the ratio of the maximum voltage to the minimum voltage measured at points along a transmission line. If you picture a long, narrow swimming pool and make waves in the center, these wave will travel toward either end of the pool. These waves are travelling waves, they move away from the source at a certain speed. If you measure the amplitude of the waves at different points along the length of the pool the wave tops would reach the same height at all distances from the source, neglecting any energy dissipation in the pool. We'll talk more about dissipation (line loss) later. This would give a SWR of 1, the amplitudes at all points are the same, therefore maximum equals the minimum and the ratio equals one. When the wave hits the end of the pool, a reflected wave will travel backwards and constructively and destructively interfere with the incident wave. This will create standing waves. If the reflected wave is the same amplitude and frequency as the incident wave, absolute null points will exist, nodes. These nodes will have absolutely no wave motion, the water stands perfectly still at these points. The waves totally destructively interfere. The SWR will be infinity for this case. There is a peak amplitude, at the point of constructive interference, and that magnitude gets divided by the zero amplitude at the node, thus the ratio is infinity. If we have the perfect antenna and impedance match, no energy is reflected back, all energy is radiated by the antenna. We then have an SWR equal to one. In practice we normally strive for an SWR between 1 and 2. A small amount of the energy is reflected back, some is absorbed in the antenna and most is radiated, hopefully in the direction we want (that's another very big subject!). Most new solid state transmitters start to reduce output power to protect themselves if they see a tranmission line SWR greater than 2. We mentioned line loss earlier, it actually improves the SWR that a transmitter sees on a poorly matched antenna. If we think back to the pool situation. We know that actually the waves get smaller as they travel farther. Thus when one is reflected back it is already smaller then the source, it also continues to decrease in amplitude as it moves back to the source. At the source the waves moving away have the largest amplitude and the waves coming back are much smaller in amplitude. Therefore the SWR at the input (transmitter end) is always less than the SWR at the output (antenna end). Therefore long, high loss lines will improve the SWR measured at the input end and could even cover up a very lousy antenna match. A good SWR doesn't necessarily mean the antenna is working well, just that the power isn't coming back. A dummy load has an excellent SWR but makes a lousy antenna. When working with antenna tuning and matching, short transmission lines will help your SWR meter tell what's really happening at the antenna end of the line. |
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TREASURER'S REPORT
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