Massasoit Amateur Radio Association Founded January 6, 1962 PO Box 428 Bridgewater, MA 02324 November 1995 A CHRISTMAS PARTY By: Maryanne N1SGW HO HO club members, its that time of year again and this year we decided to have something different. Our Christmas Party will be held at PUB 106 1300 PLYMOUTH STREET, E. BRIDGEWATER. It will be on our regular club meeting night which is December 19 at 7:00. We will have three choices for meals: CHICKEN SUPREME, LONDON BROIL or BROILED SCROD. This will be a full course meal including dessert. The price will be $10.00 (PRICE INCLUDES MEAL, TAX AND TIP) The club will supply the coffee. We will also have a few gifts. It sounds like a great evening for food and conversation. If interested please see Maryanne at the November meeting or call her at (508)279-1715. Payment and choice of meal must be made by December 1,1995. YMCA FALL FROLIC On October 22, the East Bridgewater YMCA sponsored their annual Fall Frolic Road race. Last year, the entire race was worked by Gary and Mary Ann DeCoster, WA1CIM & N1SGW, along with Joe Deree, N1SGU. This year more people were able to show up and help out, and we had a good time in the process. Thanks go out again to Gary and Mary Ann, who organized the communications for the race, along with Carl, N1FYZ, Warren, N1CGK, Joe, N1SGU, and Kathie, N1SGT. They provided communications and safety by providing traffic control during the two races that day. The effort was a success for the hams. During discussions after the race, the consensus was that a team of at least 8 people next year would really be optimum. After the race, Gary invited everyone back to the YMCA grounds where the race sponsors were putting on a hamburg and hot dog barbecue. Gary also made sure that everyone received a T-shirt for helping during the race. The Fall Frolic was an enjoyable way to spend an autumn afternoon. Look for it again next year! FIRST NIGHT UPDATE Plan for FIRST NIGHT Carl Aveni, N1FYZ, gave an update on FIRST NIGHT. MARA still needs operators, and there are possible plans to operate a special event station again. This year, the event will be scaled back to include only indoor events, and MARA members have been taken off the parking detail. Plan on being warm and having fun - or wearing a sweater and visiting the Asiaf Arena to see some excellent figure skating. Either way, its a great way to spend New Years Eve. Contact Carl for more information. ARRL PHONE NUMBERS Several months ago, the ARRL changed its phone numbers and area code. As a reminder the phone numbers for the BBS are; Voice (860) 594-0200 Fax (860) 594-0259 BBS (860) 594-0306 For your reference, electronic methods of contacting the ARRL are; MCI Mail (2155052); Compuserve (70007,3373); America Online (HQARRL1); Genie (ARRL); and Prodigy (PTYS02A). SECRETARY'S NOTES Meeting held on October 17, 1995. Called to order at 8:12PM with 25 members and guests present. Treasurers Report: Opening balance, $1085. Closing balance, $674 Repeater report: Jay Zappulla, N1FDX, went into further detail regarding the repeater maintenance as noted in the October newsletter, and made a public 'thank you' to Dave Bourque, WB1FLD, for all his help. Packet BBS: Steve Meuse, N1JFU, said that the repeater was operating fine, with no problems to report. Carl Aveni, N1FYZ, discussed the two upcoming EOC drills - the trial run on November 8 (see details elsewhere in this issue) and the actual drill on December 13. Both drills are paid drills, and expected to be day-long events. Carl also made a motion to give one of the unused club power supplies (used on the old repeater) to Dave Bourque, WB1FLD, as a thank-you for all his generous help with the repeater and other items over the years. The motion was unanimously accepted. Gary DeCoster, WA1CIM, discussed the upcoming YMCA Fall Frolic road race. See details elsewhere in this issue. Bruce Hayden, NI1X, told the club about a BSA Special Event to be held at the Marshfield fair grounds in May 1995. WARC has been asked to provide security communications and a special event station, and is asking MARA volunteers for our help as well. Bruce also spoke on the Plymouth Plantation special event. Details elsewhere in this issue. Mary Ann DeCoster, N1SGW, brought up the possibility of having the December meeting at the Pub 139, as a combination meeting and Christmas party. The motion was unanimously accepted. More details in the December issue. Lenny Amabile, N1MII, nominated Jim Ambrosio, WB2QVA for membership for the remainder of 1995 with waiver of dues for the remainder of the year. The motion was unanimously accepted. Ron Smith, N1PXX, nominated Priscilla Imhoff, KB1BPS, for membership for the remainder of 1995 with waiver of dues for the remainder of the year. The motion was unanimously accepted. Frank Hayes, N1OGP, nominated Mike Wilbur, N2JWW, for membership for the remainder of 1995 with waiver of dues for the remainder of the year. The motion was unanimously accepted. PACKET RADIO Networking and special packet protocols This is a sample of some of the more popular networking schemes available today. By far, there are more customized networking schemes used than listed. Consult your local packet network guru for specific network information. Downloaded from the Internet. (author unknown) Are there any other protocols in use other than AX.25? AX.25 is considered the defacto standard protocol for amateur radio use and is even recognized by many countries as a legal operation mode. However, there are other standards. TCP/IP is used in some areas for amateur radio. Also, some networking protocols use other packet formats than AX.25. Often, special packet radio protocols are encapsulated within AX.25 packet frames. This is done to insure compliance with regulations requiring packet radio transmissions to be in the form of AX.25. However, details of AX.25 encapsulation rules vary from country to country. What is TCP/IP? TCP/IP stands for Transmission Control Protocol/Internet Protocol. This is commonly used over the Internet wired computer network. The TCP/IP suite contains different transmission facilities such as FTP (File Transfer Protocol), SMTP (Simple Mail Transport Protocol), Telnet (Remote terminal protocol), and NNTP (Net News Transfer Protocol) The KA9Q NOS program (also called NET) is the most commonly used version of TCP/IP in packet radio. NOS originally was written for the PC compatible. However, NOS has been ported to many different computers such as the Amiga, Macintosh, Unix, and others. Smaller computers like the Commodore 64 and the Timex- Sinclar do not currently have version of NOS available. Networking Schemes What are some of those other networking schemes? During the early days of amateur packet radio, it became apparent that a packet network was needed. To this end, the following packet network schemes where created. Digipeaters The first networking scheme with packet radio was Digipeaters. Digipeaters would simply look at a packet, and if it's call was in the digipeater field, it would resend the packet. Digipeaters allow the extension of range of a transmitter by retransmitting any packets addressed to the digipeater. This scheme worked well with only a few people on the radio channel. However, as packet became more popular, digipeaters soon were clogging up the airwaves with traffic being repeated over long distances. Also, if a packet got lost by one of the digipeaters, the originator station would have to retransmit the packet again, forcing every digipeater to transmit again and causing more congestion. KA-Nodes Kantronics improved on the digipeater slightly and created KA- Nodes. As with digipeaters, KA-Nodes simply repeat AX.25 frames. However, a KA-Node acknowledges every transmission each link instead of over the entire route. Therefore, instead of an end- to-end acknowledgment, KA-Nodes allow for more reliable connections because acknowledgments only carried on one link. KA-Nodes therefore are more reliable than digipeaters, but are not a true network. It is similar like having to wire your own telephone network to make a phone call. NET/ROM NET/ROM was one of the first networking schemes to try to address the problems with digipeaters. A user connects to a NET/ROM as if connecting to any other packet station. From there, he can issue the NET/ROM commands to instruct it to connect to another user locally or connect to another NET/ROM. This connect then connect again means that to a user's TNC, you are connected to a local station only and it's transmissions does not have to be digipeated over the entire network and risk loosing packets. This local connection proved to be more reliable. NET/ROM don't use all of the AX.25 protocol. Instead, they use special AX.25 packet called Unnumbered Information (UI) packets and then put their own special protocol on top of AX.25. This is again used to increase efficiency of it's transmissions. NET/ROM is a commercial firmware (software put on a chip) program that is used as a replacement ROM in TAPR type TNC's. Other programs are available to emulate NET/ROM. Among them are TheNet, G8BPQ node switch, MSYS, and some versions of NET. NET/ROM nodes, at regular intervals, transmit to other nodes their current list of known nodes. This is good because as new nodes come on-line, they are automatically integrated in the network, but if band conditions such as ducting occur, often unreachable nodes are entered into node lists. This causes the NET/ROM routing software to choose routes to distant nodes that are impossible. This problem requires users to develop a route to a distant node manually defining each hop instead of using the automatic routing feature. ROSE Rose is another networking protocol derived from X.25. Rose nodes have a static list of the nodes it can reach. For a user to use a ROSE switch, he issues a connect with the destination station and in the digipeater field places the call of the local rose switch and the distant rose switch the destination station can hear. Other then that, the network is completely transparent to the user. The static routing tables ROSE uses ensures that packet routing does not use unreliable links such as NET/ROM suffers from. However, ROSE suffers from it's inability to change it's routing table as new nodes come on line. The operator must manually change every routing table, thus ROSE networks require greater maintenance times. BBS message transfer Many of the BBS programs used in packet radio allow for mail and bulletins to be transferred over the packet radio network. The BBS's use a special forwarding protocol developed originally by Hank Oredsen, W0RLI. Besides full service BBS's, many TNC makers have developed Personal BBS software to allow full service BBS to forward mail directly to the amateurs TNC. This allows operators to receive packet mail at night and avoid tying up the network during busy hours. COMPUTER VIRUSES compliments of Carl Aveni, N1FYZ [Editors note: We couldn't publish every virus on Carl's list because there were just too many of them. And we had to omit others because, well, you know Carl's tacky sense of humor.....] BOBBITT VIRUS: Removes a vital part of your hard disk then reattaches it, but it never works again the way you expect it. OPRAH WINFREY VIRUS: Your 200MB hard drive suddenly shrinks to 80MB, then slowly expanded back to 200MB. ROSS PEROT VIRUS: Activates every component in your system, just before it quits. TED TURNER VIRUS: Colorizes your monochrome monitor. ARNOLD SCHWARZENEGGAR VIRUS: Terminate and stays resident. It'll be back. DAN QUAYLE VIRUS: their is sumthing rong with yor komputer, ewe cant figyour outt watt. RANDALL TERRY VIRUS: Prints "Oh no, you don't" whenever you choose "Abort, Retry, or Fail". ADAM & EVE VIRUS: Takes a couple of bytes out of your Apple (this one was for WA1CIM) FREUDIAN VIRUS: Your computer becomes obsessed with marrying its own motherboard. OLIVER NORTH VIRUS: Causes your printer to become a paper shredder. SEARS VIRUS: Your data won't appear unless you buy new cables, and a set of shocks. CLEVELAND INDIANS VIRUS: Makes your 486/50 machine perform like a 286AT CHICAGO CUBS VIRUS: Your PC makes frequent mistakes, and it comes in last in the reviews, but you still love it! AT&T VIRUS: Every three minutes it reminds you what great service you're getting. MCI VIRUS: Every three minutes it tells you you're paying too much for the AT&T Virus. SILENT KEY It came to our attention at the October meeting that Carl Pearson, WA1DCR was a silent key on August 18,1995. Carl checked in on the net from time to time from his nursing home in Kingston. Easily recognized by his shaky voice, he will be missed by all who knew him. WARC PLYMOUTH PLANTATION EVENT It's that time of year again - Thanksgiving will be just around the corner when you read this. Bruce Hayden, NI1X, president of WARC, has extended his annual invitation to work the Plymouth Plantation Special Event station the weekend after Thanksgiving. Come on down and be prepared to work a casual, fun operating event. Then you can spend a little time meandering through the village of Plymouth in the year 1625. Bruce mentioned that most people tend to come down on Saturday, and then rigs are left wanting on Sunday for lack of operators. If you can, think about coming down on Sunday instead to share the wealth. This is also the last weekend of the year for Plymouth Plantation. It will close for 1995, to reopen in the spring of 1996. See you there! EDITORIAL by Bob Mandeville, N1EDM There was a discussion at the October club meeting, at times quite heated, regarding the 'tone' of the repeater over the past several months. The MARA machine has been barraged with dissatisfactions such as airing of complaints over the air before privately speaking with the individuals involved; repeater police; touch-tone Charlies, etc. The members said that they were, mildly speaking, displeased with what they had been forced to listen to. They want the repeater to focus more on the fun and camaraderie of hamdom, discussing radios, PC's, and propagation, not grudges. Charlet, N1VQZ, had the best idea. She suggested that an editorial be written, reminding members about everything that is right with the Massasoit Amateur Radio Association. Lets begin by saying that there are several excellent Amateur Radio clubs on the South Shore, most of which have had long, productive, and proud histories. The Massasoit Amateur Radio Association is very close to the top of that list. Take a look at your club, and what you have accomplished in the last several years. An excellent example is Public Service; one of the foundations of amateur radio. MARA has shown this time and again at Haunted House, First Night, the YMCA road race, MEMA and EOC support during hurricanes, and most recently, Skywarn activities. Most importantly, MARA is a key supporter for Eastern Edison, who depend on our talent, skills, and involvement during any accident or malfunction at Pilgrim Nuclear Power Plant. MARA helps by providing professional caliber communications. In a joint effort with WARC, our sister club, we run an efficient VE team for area hams, with ideas on expanding to more frequent sessions. MARA members consistently put together a great Field Day effort with the emphasis on fun & food, not competition. How about JOTA?? And did you ever notice that there doesn't seem to be a contest that goes by without someone in the club talking it up and working it. Last year, the membership dug deeply into their own pockets to purchase and install a new, state of the art repeater. We are now in the follow-up phase of getting the new shack on line. MARA members, with the volunteer help of two licensed electrician/hams, have been donating whatever free time can be spared from family responsibilities to wire the new repeater shack per code; no small feat in itself. And there is an eye on more improvements. MARA has invested in, and supported, a top-notch BBS and Node system to fill a void in our area, enabling packet users to pass local messages, and to keep in touch with US and international packet news and information. MARANEWS is something else to be proud of. Beginning with the inspiration of Sam Pope, W1KGU, the newsletter has evolved with technology into what it is today, with ideas and contributions from the membership. When speaking about the MARA members, we are referring to you, the people who care. The people who pitch in when needed. Be proud of what MARA stands for, its reputation, its camaraderie and brotherhood. Look at the positive side of MARA. Thanks. NEW SOFTWARE UPLOADS Check Ham Shack and Sanctuary for the following software. JVFAX71.ZIP; JVFAX Ver 7.1 REV 950901 from DK8JV. The new JVFAX is here with English Docs and New Diagrams. Have a look and lets see whets new in 7.1. RXLAYOUT.GIF; RX Circuit for JVFAX-HAMCOM-PKTMON simple but very effective from Ron Wilson WB5NBQ DEMOD.GIF; a JVFAX SSTV and FAX Demodulator with bandpass filtering. Works good on HF as well as VHF-UHF. Extra filtering helps on the low bands. Designed by KI6ZD Stockton Satellite Imaging Group. PC-TRACK V 3.1; 3D Satellite Tracking Track 300 satellites at a time. 3D and mercator projections. VGA graphics. Show footprints, altitude lines, lines of sight, space & ground points, solar position. Predict visible passes. Compute solar illumination, Doppler shift, phase, position, range rate. Import data from NORAD, AMSAT. Uses SGP4/SDP4 propagation. Capture graphics to PCX files. Have you run out of antenna inovations? Read on!! The Lure of the Ladder Line (part 1 ) -- used with permission from QST and the American Radio Relay League, Inc. I was feeding a short, limited-space antenna with coaxial cable. Everything seemed to be okay, but was it? By Steve Ford, WB8IMY Assistant Technical Editor Like many hams, I live in a home that's inhospitable to antennas. My house sits on a 100-foot square lot with trees along the back. I always hoped to be the proud owner of a tower and an HF beam antenna, but that was out of the question. What about a vertical? Well, I'd have to bury plenty of radial wires in the rocky Connecticut turf. That didn't sound like fun. I could buy a vertical that didn't require radials, but those antennas were a bit out of my price range--and their awkward, spiky appearance didn't blend well with the landscaping. A wire antenna seemed to be the ideal candidate. Hanging a wire between two trees wasn't a problem, but there was still the aesthetic issue to consider. As much as I love ham radio, I didn't want to arouse the anger of my wife and neighbors by installing a copper monstrosity that looked as if it was spun by a mutant spider. All I wanted was a simple, low-profile dipole that I could operate on a number of HF bands. Perhaps I could string up a single dipole and feed it with coaxial cable, using an antenna tuner to load it on several bands. The length of the antenna wouldn't be critical. I'd put up as much wire as possible and let the tuner worry about transferring power to the system. Even under high SWR conditions, where lots of energy is reflected back and forth between the tuner and the antenna, a substantial amount of RF would still be radiated. That sounded fine to me. I put up a 66-foot dipole and fed it with low-loss Belden 8214 coaxial cable. Sure enough, my antenna tuner was able to load it on all bands from 40 through 10 meters--more or less. The tuner balked a bit on 17 meters and it was very touchy on 10 meters. (Sometimes it arced with a startling snap!) Despite the problems, I used my system to work 75 new countries in just a couple of months, finally clinching my DXCC award. I also enjoyed a number of stateside contacts. The SWR was very high on most bands. At 100 watts output, however, the heavy- duty 8214 withstood the mismatch without noticeable heating. (I'd certainly notice it at higher power levels, though!) The antenna looked great and seemed to be performing well. Even so, I knew I was losing power in the cable and I wondered how it was effecting the overall performance. While considering the alternatives, my thoughts drifted to trap dipoles. Yes, a trap dipole can be resonant on several HF bands, but the coil-and-capacitor traps tend to be bulky and prone to loss. How about a fan dipole? Just attach several resonant dipoles to the same center point and feed them all with one cable. Too big and ugly! (We're back to the spider web problem again.) How Bad Can it Be? I allowed my thoughts to drift for more than a year--until I met Dean Straw, N6BV, our new Assistant Technical Editor here at League Headquarters. Dean's field of expertise is antennas and propagation, so I peppered him with questions about my antenna situation. Yes, he said, my original assumption was correct. A nonresonant antenna will work--even with sky-high SWR--if the feed-line loss is low enough. My 8214 cable should certainly offer low loss. The ARRL Handbook chart indicated that its loss was less than 1.5 dB per 100 feet at 100 MHz. I was only using 50 feet and my highest operating frequency was 29.60 MHz. (Cable loss decreases as feed-line length and frequency decrease.) So how bad could my losses be? Very bad! I made the mistake of underestimating the loss under high SWR conditions. Dean used a computer program to calculate the 8214 loss on various HF bands when used with my 66-foot dipole. You can see the results in the middle column of Table 1. I was shocked to say the least! My 100-watt signal was reduced substantially on some frequencies. (The higher the dB figure, the more power is lost in the cable. A three-dB loss represents a 50% reduction.) cont. next month... 73 from the staff at M.A.R.A.