<\/p>\n
Prez Sez
\n10 meter Contest
\nWindjammer Race
\nDoppler vs Rotating Antenna Direction Finding
\nChatter
\nVanity Call Signs<\/p>\n
Pres Sez<\/strong><\/p>\n Drat! I had to work last Saturday. That means I missed the monthly club I just found out (from board member Hank KG6EE) that the Stanford Linear The upcoming club meeting on Friday, August 15 Did you know that the NPSARC (Monterey Naval Postgraduate School Amateur Hey all you NWS weather spotters, did you know that the NWS Monterey Did you know the long-awaited amateur radio satellite, AMSAT’s Phase Cap, KE6AFE<\/p>\n K6BDK 1st Place in 10 meter<\/strong> Contest<\/strong><\/p>\n Frank Carroll, K6BDK, won first place for a single operator on CW, low Packet<\/strong> The Windjammer Race is a sailboat race that begins in San Francisco on What does packet radio have in common with sailboat racing you ask? Well, We will need two operators in the van on the wharf, and one operator Anyway, everyone has a lot of fun. The crew from the Santa Cruz Yacht If you know your way around a packet station or computer (equipment is – Thanks and 73, Steve Smardan<\/p>\n Doppler vs Rotating Antennas<\/strong> The following is my answer to questions about doppler vs rotating antenna Doppler has a bunch of problems. This is NOT intended to discourage anyone 1. A doppler DF can only display the direction of *ONE* transmitter. 2. Switched doppler is susceptible to switching noise which acts as modulation 3. The typical vertically polarized doppler system does not work well 4. Doppler is sensitive to fox frequency. The doppler receiver measures 5. Doppler is sensitive to rotation frequency and FM demodulator distortion. Intech elected to use 4.1KHz. Most of the harmonics are outside the IF It turned out that the conventional balanced multiplier FM demodulator 6. Doppler is sensitive to modulation audio. The response time of the 7. Doppler antenna patterns are very sensitive to nearby antennas and On the roof of a car, the AM\/FM antenna and other radio antennas create 73 Magazine carried a series of articles in the Homing-In section based One place where a rotating antenna is far superior to doppler is tracking – Jeff, WB6SSY, ()<\/p>\n Chatter<\/strong><\/p>\n By Art Lee, WF6P<\/p>\n I have always been interested in the Search For Extra Terrestrial Intelligence In his article, Mr. Klass pretty much disproves any of the UFO sightings The article, “When E.T. Calls Us,” by Seth Shostak discusses Bad news. A ham, Michael Heindl, of Citrus Heights made the recent centerfold Although I have been out of town for the past two club breakfasts, I Shucks! My old Navy buddy Stu Keller, K9WNU, and his XYL returned to Boy, was I having fun! Was banging away on CW with my pal Marsha, AB7RJ, Streams of uncontrolled dits and dahs went out over the airwaves. Nothing Interested in writing articles? Leon Fletcher, AA6ZG, tells you how to We had an 8 yr old visitor on our July 21st Monday nite net. Mellissa, Vanity Call Signs<\/strong><\/p>\n The FCC announced on July 3 that Gate 3 for Advanced Class licensees The date for opening Gate 4 has not yet been announced. The new fee of <\/p>\n <\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" August 1997 Short Skip Prez Sez 10 meter Contest Windjammer Race Doppler vs Rotating Antenna Direction Finding Chatter Vanity Call Signs Pres Sez Drat! I had to work last Saturday. That means I missed the monthly club breakfast that …<\/p>\n
\nbreakfast that was held at Lyons Restaurant on 41st Avenue. I hear that
\neverybody had a good time though. Have you been to one of these yet? They’re
\nanother chance to talk about our avocation with like-minded club members.
\nEyeball sessions are always fun for hams. One great place for eyeball sessions
\nis at the Foothill College swap meet (held the second Saturday of the summer
\nmonths). We tried to avoid scheduling a club breakfast on that day. This
\nlast Saturday the Club breakfast faced competition
\nfrom the Pajaro Valley Century bike race and the Horseman’s Association
\nFireworks 50 mile ride and numerous other events (Summer in Vacationland!).
\nWith all our different activity schedules, nobody can make it to every breakfast
\nbut we hope you can make it sometimes. We plan to have them monthly as long
\nas that’s what suits us. The next one will be at Jeffery’s
\nRestaurant 2050 Soquel Avenue (cross street: Capitola Road), on Saturday,
\nSeptember 6, 9AM .<\/p>\n
\nAccelerator Center gives tours to groups if arrangements are made in advance.
\nIs anybody interested in a club field trip? We’d have to arrange transportation
\nand get a list of people who will go before we make the arrangements with
\nSLAC. Sounds very interesting to me. I’ve never seen the accelerator up
\nclose, except while driving over it on Highway 280. Think about it.<\/p>\n
\n(always the third Friday of the month) sounds like a good one. Al
\nKM6VV will present a project he’s been working on for awhile in his “spare”
\ntime. I understand it’s pretty fancy and could possibly help us with finding
\n“hidden transmitters.” Al is an accomplished computer programmer
\nas well as amateur radio operator and this project involves both of those
\nskills. As I write this, I hear him and Jeff WB6SSY talking over some final
\ndetails of Al’s project on 2 meters. I just hope Al finishes the project
\nin time to demonstrate it to us at our meeting!<\/p>\n
\nRadio Club) is planning to re-institute their famous Winterfest this winter?
\nIf you’ve never been to one of those, you’re in for a treat.<\/p>\n
\nForecast Office (MTR) is watching for weather reports on amateur radio full
\ntime now? They now have a computer in their office that runs APRS packet
\nradio software 24 hours a day to receive weather statistics from hams throughout
\nCentral California who are also running APRS.<\/p>\n
\n3D, may be delayed again (from its currently scheduled September launch
\ndate)? The European Space Agency (ESA) significantly increased its estimate
\nof vibration levels the Phase 3D payload would be exposed to aboard the
\nAriane 502 rocket. The revised estimates mean AMSAT will have to move fast
\nto make structural changes in the Phase 3D spaceframe in order to withstand
\nthe anticipated rougher ride.<\/p>\n
\npower for the Santa Clara Valley Section in the 1996 Ten meter contest.
\nFrank got a surprize when he received the certificate in the mail from the
\nARRL last week. Frank said, “I never expected that” Good going
\nFrank!<\/p>\n
\nOperators Needed for Windjammer Race<\/strong><\/p>\n
\nFriday August 29 at about 11:00AM and ends off the Santa Cruz Wharf. ARES
\nhas provided support to the Santa Cruz Yacht Club for the last several years
\nin the form of the ARES Van and warm bodies trained in the art of packet
\nradio.<\/p>\n
\nthe way we used to send lists of boats that have finished back to the yacht
\nclub, was one by one over the marine VHF, competing with not only Joe &
\nFred discussing fishing, but also a very loud fog horn. Using packet radio
\nall we have to do is enter a list of finishers into the computer and send
\nit back to another packet station set up at the yacht club. This allows
\nthe yacht club to let family and friends of racers know when they have finished.
\nIt also helps the race committee score the race much faster.<\/p>\n
\nat the station at the yacht club per shift. The van should get to the wharf
\nabout 6 P.M. and a second operator around 7 P.M., with someone at the yacht
\nclub at 6 P.M. to set up the station and establish the packet link with
\nthe van. Oh yes, did I mention that boats will be finishing until the wee
\nhours of the morning? There will be plenty of coffee, and you won’t be overworked.
\nMaybe there are a few of you out there who (unlike me) actually enjoy getting
\nup before daylight.<\/p>\n
\nClub park a motor home out on the end of the wharf, there is clam chowder
\nall night long at the yacht club, and about a hundred boats full of cold,
\ntired, appreciative sailboat racers who will pack the Santa Cruz Harbor
\nfor the weekend.<\/p>\n
\nsupplied) and can spare a few hours call me Steve Smardan at (408)476-6421
\nor email “n6tgm@juno.com”.<\/p>\n
\nfor Direction Finding<\/strong><\/p>\n
\ndirection finding from rec.radio.amateur.equipment.<\/p>\n
\nfrom using doppler, just to recognize its limitations. Credibility check:
\nI helped design the AN\/SRD-22 doppler direction finder for Intech Inc for
\nuse by the US Coast Guard in approximately 1975.<\/p>\n
\nIf there are any other sources of signal (reflections, other xmitters, adjacent
\nchannel junk, computer noise, synthesizer spurious signals, harmonics of
\nclock oscillators, ignition noise, images, etc.) the reading will be erroneous.
\nReflections is the real killer. A ground bounce mixed with a direct signal
\nwill yield horrible results. (Incidentally, the reason most dopplers have
\nrather large antenna ground planes is to reduce ground bounce).<\/p>\n
\nsidebands. These sidebands (harmonics of the switching frequency) will cause
\nstrong adjacent channel signals to mangle the bearing. The typical “Roanoak”
\ndesign is highly susceptible to this. Doppler Systems uses DGMosFet switches
\nwhich have a much “softer” (less rise time) switching characteristic.
\nIntech used a modified sine wave drive to literally modulate the PIN diodes
\ninstead of switching. It totally eliminated the problem, but sensitivity
\nwas reduced. PIN diode matching was also very critical.<\/p>\n
\nwith horizontally polarized signals. Building a horizontally polarized doppler
\nis no major challenge, but nobody seems to have done it.<\/p>\n
\nthe phase shift from the antenna to the FM demodulator. Any change in receiver
\nsystem phase shift appears as a substantial directional error. The worst
\nerror is caused by the crystal IF filter. The phase shift from IF center
\nto filter edge goes through radical phase changes. An AFC (automagic frequency
\ncontrol) is mandatory to keep the signal in one place on the crystal filter
\ncurve.<\/p>\n
\nThere two schools of thought here. Doppler Systems uses about 300Hz rotation
\nfrequency. This is good for insuring that the signal will remain in the
\nIF bandpass (no AFC) but results in harmonics of the 300Hz in the bandpass.
\nThese harmonics cause bearing errors and linearity (approximation of a circle)
\nerrors. The typical commutating audio bandpass filter will not remove harmonics.<\/p>\n
\nbandpass. Combined with the PIN diode modulation technique, this yielded
\na very low distortion sine wave at the demodulator and very good linearity.
\nHowever, the group delay (phase shift error) of the IF crystal filter was
\nfar worse at the edges (+\/-4KHz) than it was near the center (+\/-300Hz).
\nAFC became mandatary.<\/p>\n
\nwas also slightly sensitive to signal level. Since the AN\/SRD-22 was both
\nan AM (121.5 aircraft) and FM (Marine VHF band) receiver, an ALC (automagic
\nlevel control) was used. The error was not large and can be probably be
\nignored.<\/p>\n
\ndoppler DF is totally dependent upon the Q of the doppler tone bandpass
\nfilter. The wider the bandwidth, the faster the DF. If you make the filter
\ntoo narrow, it takes forever to get a bearing. However, too wide and FM
\naudio modulation and fox tones will leak through the filter and mangle the
\nbearing. One favorite trick is to use a 300Hz fox tone to mess up the Doppler
\nSystems DF’ers.<\/p>\n
\nreflections. The AN\/SRD-22 had to be mounted at the very top of the mast.
\nUnfortunately, almost every other piece of electronics equipment wanted
\nto be in the same place.<\/p>\n
\nhorrible errors. Nearby antennas from other hunters at the starting point
\nwill mutilate the pattern. This is why the various DF books say (several
\ntimes) that the ONLY way to get a decent bearing is while moving. Moving
\ntends to average out reflection errors. While the error at a given location
\nmay be severe, a few feet away might be perfectly acceptable. The trouble
\nis you have no idea where there is a reflection free location. Moving while
\nDFing is the only way.<\/p>\n
\non rotating yagi and quad antenna direction finding. These are basically
\nAM (signal strength) systems. The advantage is that you can easily see multiple
\ntransmitters, recognize reflections (they tend to blur), do NOT require
\nan AFC, and have an easily controllable antenna pattern (using boresight
\ncalibration). However, driving down the freeway with a spinning 4 element
\nquad is a great way to attract the constabulary. Short transmissions are
\nalso difficult to see. Equipment complexity is about the same. Having dealt
\nwith doppler professionally and recognized its limitations, I’m very partial
\nto rotating antenna DF.<\/p>\n
\na jammer. With a jammer, you have *TWO* signals on a frequency (the person
\ntrying to talk and the jammer). A doppler DF will yield a bogus direction
\nbecause of the two signals. A rotating antenna will show both signals.<\/p>\n
\n(SETI) program. As many of us know, Aptos resident Dr. Frank Drake, former
\nUCSC professor of astronomy, has spent most of his life pursuing this subject.
\nWhen I asked my son Randy, N6UZI, if his astronomy club or his favorite
\nmagazine, Astronomy, covered this or UFO topics he replied, “Nahhh
\n…. we are serious star gazers, not speculators.” Lo and behold, the
\nSeptember issue of Astronomy headlined, “Is Anybody Out there? On the
\nTrail of UFOs.” OK, so now what? I personally don’t believe we have
\nbeen visited by UFOs within the past couple of centuries. But I am convinced
\nthat there has to be intelligence in space and the sheer numbers would be
\nenough to make the odds pretty great that Dr. Drake is correct. Oh, Dr.
\nDrake was a buddy of Dr. Carl Sagen who believed the same. Well, I was rewarded
\nto find the article, “A Field Guide To UFOs,” by my favorite aviation
\nwriter, Phillip J. Klass. Mr. Klass was the Avionics (he coined the term
\nin the 60’s) editor of Aviation Week for over 45 years.<\/p>\n
\n(sorry folks). His studies of the UFO phenomenon over the years proved that
\nmuch to him. The ending for his article does read, ” So far, I’ve had
\nno luck (in sighting a UFO) but who knows, perhaps tomorrow and or next
\nweek. He has authored several books on that subject. Read his: UFOs: the
\nPublic Deceived; UFO Abductions: a Dangerous Game, and The Real Roswell
\nCrashed Saucer Coverup. All published by Prometheus Books, Amherst, NY.<\/p>\n
\nthe attempts by space scientists to copy radio signals from space. If they
\nsucceed in that, think of the QSL card they will receive!<\/p>\n
\nof a Sacramento neighborhood newspaper, Sunday Neighbors. A big, bold photo
\nof the ham astride his 65 foot tower was shown. The piece, written by a
\nlocal reporter, was highly biased against the ham who had tried, unsuccessfully,
\nto placate his neighbors effected by TVI. Locals complained about his transmissions
\nand the FCC, who would not make him stop transmitting. Arguments in favor
\nof the neighbors who complained about interference with their telephones
\nwere presented by the reporter.<\/p>\n
\nam happy that our club president has rejuvenated this old SCCARC custom.
\nGood on you, Cap! As the older club members may recall, Norm, N6DAC, and
\nhis XYL Beth, W6RYL, coordinated the breakfasts for the club for many years.<\/p>\n
\ntheir home QTH in Sterling , Illinois. We had lotsa fun doing antenna work
\nwhile they were here. We still had some antenna work to do on a defunct
\nvertical I inherited from Joe Myers, N6AOG, many years ago. While cleaning
\nup the segments of the tubing, I accidently moved one of the traps. The
\nbook says, “DON’T MOVE THE TRAPS!” Somehow, I missed that important
\nstep. I shipped his wonderful AEA SWR analyzer back to Stu the other day
\nbut I couldn’t keep it forever. Stu has set up a mobile station in his motor
\nhome. Put one of those multi-band Outbacker antennas on his rooftop luggage
\nrail, had a poor ground, but in a pouring down rain, reported excellent
\nreports on all sigs sent. “Everything that should have made my signals
\nbad were there, yet the transceiver and antenna put out a great signal!”<\/p>\n
\nin Yacolt, Washington, when my son’s MFJ DeLuxe electronic Keyer went bonkers.<\/p>\n
\nI could do would stop it. I shut down the keyer, restarted it, the same
\nthing happened. It just went nuts. I tore the cover off the keyer and noted
\nthe date on the battery. “Use before July 1992.” Marsha patiently
\nawaited my return to the frequency for about 20 mins. It took me 25 minutes
\nto rob a 9 volt battery out of my 19 month old grandson’s toy car and install
\nit in the keyer. Too late. Oh well.<\/p>\n
\nmake good endings for them in his latest article in the August issue of
\nWriter’s Digest, a top-notch guide magazine for writers.<\/p>\n
\nKF4KQH, came up on freq to check in. Her QTH was Georgia. “I have a
\nsouthern call sign but not a southern accent,” she said. “My father
\nis in the Army so I guess I’m really from everywhere” Mellissa was
\na real rag-chewer. “I used to creep into my dad’s ham shack, turn on
\nhis HF receiver, and tune around the band and listen. That was real fun.”
\nShe was vacationing in Santa Cruz for 8 days.<\/p>\n
\nwill open on Aug. 6, 1997. Details on the Vanity Call program can be found
\non the ARRL WWW site at www.arrl.org or by calling the FCC National Call
\nCenter at 1-888-CALL-FCC. To file, use Form 610-V available via the FCC
\nInternet Homepage at <http:\/\/www.fcc.gov\/wtb\/amradsrv.html> or from
\nARRL HQ. The fee remains $30 for a 10 year license until Sept. 16, 1997.<\/p>\n
\n$50 for the 10 year license will take effect Sept. 16, 1997.<\/p>\n