The Rochester VHF Group The VHF Journal Volume 66, Issue 3 November 2013 The next regular meeting of the Rochester VHF Group will be Friday, November 8th, 2013 at 7:30 PM Doors open at 7PM.The AWA Campus is located on Routes 5 and 20 just east of the Route 444 intersection in Bloomfield, NY. The address is 6925 Routes 5 and 20. Map on last page In this issue: The Chairman Speaks! Secretary s Report Treasurer s Report The Vice Chairman s Report MUD 2013 Vibrating Plate Filter Classified Topic: AWA Museum RVHFG s Beacons Band MHz 6m 50.078 2m 144.298 1.25m 222.050 70cm 432.300 23cm 1296.257 The Chairman Speaks! Bob Nezelek W2CNS Groupers: This past month has been very busy for amateur VHF/EME radio activities by several of the club members ranging from attending NEAR-Fest in the mountains of Deerfield, New Hampshire to the mountains in Morehead, Kentucky for the yearly Microwave Update 2013 (MUD) conference. I want to thank Ken, KA2LIM for his presentation to the group. During the MUD 2013 conference we announced to the group our plans to host MUD 2014 in October 2014. The Board of Directors and the MUD cochairmen, Dave Hallidy and Frank Pollino were briefed on the activities at MUD 2013. We have a lot of work to do in the upcoming months. When you get on the air please talk about the conference to your friends. We need to put the word out that we are looking for papers to present. Continued. Published by Rochester VHF Group PO BOX 92122 Rochester, NY 14692 Editor: Tom Jennings, KV2X The VHF Journal is published by the Rochester VHF Group monthly except June-August. The subscription price is included in the membership dues. If you elect to receive the PDF version by downloading it from our website, dues are US$10 per year. In this case, you will be notified by email the day it is available for download. If you choose to receive the hardcopy Journal by Postal delivery, the dues are US$15.00 per year. Articles and comments should be submitted to journal@rvhfg.com
The Chairman Speaks! This month we will be having our meeting at the Antique Wireless Museum. We will have a brief business meeting and then we will have a tour of the new exhibits. One of my favorite displays is the 1 kw spark transmitter. It is operational and very impressive. Going to the AWA for our November meeting is becoming a traditional event and we are grateful to the AWA for hosting the group. If you are not a current member of the AWA, please consider becoming a member. Also, try to bring a guest to the meeting. W2CNS Bob Nezelek Secretary Report Freddie Sulyma, WB2GFZ Rochester VHF Group Meeting Minutes for 11 October 2013 The meeting was called to order at 1944L by Tom (KV2X). Tom welcomed everybody and asked if there was a motion to accept the minutes from the last meeting as printed in the Journal. Bill (K2TER) made the motion to accept and Dave (AB2YI) seconded. Tom asked if there was a motion to accept the Treasurer s Report from the last meeting as printed in the Journal. Dave made the motion to accept and Bill seconded. Attending: KV2X, WB2GFZ, K2TER, AB2YI, KA2LIM, Jean Kent, K2ZT. Old Business: Bob (W2CNS) and Bill (K2TER) are to attend MUD next week and report back. New Business: Tom reiterated the ability to down load PDF copy of the book Digital Signal Processing by Steven W. Smith, PH.D. for free (www.dspguide.com). After New Business KV2X made a motion to adjourn the meeting and WB2GFZ seconded the motion. Program: Ken Kent (KA2LIM/K2LIM) highlighted his VHF/UHF contesting activities which included discussions of the group s station site (Steuben County, NY, FN12MG), communication equipment and the antenna farm. Much of the group s activities can be viewed at www.ka2lim.com. Rochester VHF Group Treasurer s Report CHECKING ACCOUNT Previous Balance (as of 10/26/2013, $2030.09 Checking, $120.00 Cash) $2150.09 Income: $0.00 Membership/Renewals K2CS (Funds Deposited 10/3/13) Expenses: Annual PO Box 92122 @ 1335 Jefferson Rd, Rochester, 10/21/13) $60.00 Current Balance: $2090.09 Respectfully submitted, Freddie Sulyma, WB2GFZ, Treasurer
The Vice Chairman s Report By Tom Jennings KV2X I would like to remind everybody that the December RVHFG Meeting (Friday December 13) we will be having our yearly Tune-Up Clinic, so be thinking now about preamps, transverters, converters or filters that you would like measured and or tweaked for Noise Figure, Gain or Loss performance. The Tune Up Clinic will be held at the home of K2TER, Bill Rogers, in Webster. Stay tuned to the Journal and the website for directions. Next I would like to remind everybody of the VHF Nets directed by John, WB2BYP held each Monday and Thursday evening starting at 9:00 PM local time. The first net is the 2 meter net on 144.260 MHz USB then at 9:30 the 6 meter net starts on 50.2 MHz. If there is interest nets will QSY to the other VHF/UHF bands. Feel free to check in and check out how your VHF/UHF signal is doing as there are folks from Canada and Pennsylvania checking in on a regular basis. I hope to see you all at the next meeting on Friday, November 8 11, 2013 at the AWA Museum 73, Tom kv2x MUD 2013 Report Attending Microwave Update (MUD) 2013 in Morehead Kentucky and representing the Rochester VHF Group was Bob Nezelek, W2CNS, and Bill Rogers, K2TER. They gave a brief talk announcing MUD 2014 will be hosted by the RVHFG and invited every one to come to Rochester. Here is the Power Point presentation Bill and Bob gave to the conference:
Bill, K2TER, in front Morehead s 24m dish Albert, W5LUA, explaining dish to W2CNS Vibrating Microplate Filter By Tom Jennings KV2X As I was surfing the net the other day I ran across an interesting item which is potentially very useful for VHF/UHF/Microwave ham radio applications. It is a new type of band pass filter which uses vibrating microplates. These filters can be accurately tuned to the desired frequency. The band pass of the filters can be set to be as wide as a VHF/UHF/Microwave ham band or even less than 500 khz. I do not know how narrow.
The researchers describe the filters as consisting of two mechanical resonators. They vibrate at an adjustable frequency thanks to the piezoelectric material PZT. This material is applied to metal. Normally, the piezoelectric material vibrates perpendicular to the metal and the thickness of the layer determines the frequency. However, the frequency can be varied by making it vibrate in the same direction as the metal. Two resonators are used, which are not connected mechanically or electrically. By means of the intelligent handling of the input and output signals of the two resonators, adverse parasitic effects are negated. This is done by subtracting the output signals, while the input signals are in phase. The result is a selective filter - fourth order - that forms a band pass filter. It can be accurately tuned with the vibrating frequencies of the two resonators.
Below is a sample plot of the filter s band pass characteristisc. As you can see the insertion loss of about 16 db is quite high. The researchers are working on getting the insertion loss down to 5 db or less. Since these filters so small (much much smaller than inductors and capacitors) the researchers expect that the filters can either be integrated into a chip or bonded to the chip. It would be possible t many filters with different center frequencies and band passes will be available in a small area. Something like this would go a long way in making an inexpensive good quality multiband VHF/UHF/Microwave ( 6m through 10gig ) ham transceiver. The research was conducted by the Transducers Science and Technology Group of the University of Twente MESA+ Institute for Nanotechnology in collaboration with the CTIT Institute Integrated Circuit Design group. There was also cooperation with the spinoff company SolMateS, which is specialized in making piezoelectric layers on chips. The project is financed by Dutch Technology Foundation STW. Publication: A4th-order band-pass filter using differential readout of two in-phase actuated contour-mode resonators by Hadi Yagubizade, Milad Darvishi, Miko Elwenspoek and Niels Tas, Applied Physics Letters Sources:
http://www.utwente.nl/en/archive/2013/10/vibrating-microplates-bring-order-toovercrowded-radio-spectrum.docx/ Email from Hadi Yagubizade answering some questions. None this month. Classified Listings Meeting Location Map