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Tracy
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SJC EMCOMM Freqs
SJC1 - 147.210 + 114.8 Stockton (Stockton Pri)
SJC2 - 146.655 - 100.0 Tracy (County Pri)
SJC3 - 145.210 - 100.0 Tracy (County B/up)
SJC4 - 147.090 + 114.8 Lodi (North Pri)
SJC5 - 146.985 - 100.0 Manteca
SJC6 - 147.165 + 107.2 SDARC
SJC7 - 147.015 + 114.8 Copperopolis
SJC8 - 147.105 + 94.8 Stockton
SJC9 - 146.895 - 114.8 Mt. Oso - Disabled
SJC10 - 444.400 + 114.8 Copperopolis
SJC11 - 444.325 + 94.8 Stockton (Stockton Pri)
SJC12 - 443.825 + 107.2 Mt. Oso
SJC13 - 444.575 + 107.2 Stockton
SJC14 - 444.850 + 114.8 127.3 Tracy 
SJC15 - 444.500 + 114.8 Stockton
LLNL - 146.775 - 100.0 Livermore


TAC1 - 146.550

TAC3 - 146.535
TAC4 - 146.430
TAC6 - 156.565
TAC7 - 146.595
TAC8 - 146.445
All simplex
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N5FDL/CEVOL Repeaters

Stockton: 147.210 + N5FDL and 444.500 + K6TRK Both PL 114.8 (linked)

Copperopolis/Gopher Ridge: 147.015 + and 444.400 +  (not linked) N6GKJ 

Mt. Oso: 146.895 - N5FDL and 443.825 + PL 107.2 (not linked)

Tracy: 444.850 + KB6EMK PL 127.3

Affiliated Repeaters

Bear Mtn.: 146.090 + and 444.250 + WB6ASU Both PL 114.8 (linked)

Mt. Delux: 145.210 - PL 100.0 WA6SEK (10mi S of Tracy)

All repeaters are open to all users.

Monday
Sep082008

HF Antennas "The Easy Way"

Following up on my previous post on SWR Mythology, I want to point you to a book by my friend John Haerle, WB5IIR (SK). It’s called “The Easy Way — HF Antenna Systems” and puts the comments of Walt Maxwell into practice, sort of taking off from Maxwell’s “Another Look at Reflections” and continuing down a path most hams can understand.

The book is published by WorldRadio and is available for ordering from their web site. Look on their “Products” page. I would have linked directly to the book’s page, but WR has one of those oh-so-fashionable sites where you don’t get actual page links.

The books costs $12 plus $3 S&H and 93-cents sales tax if you live in California.

Here’s some information from the site:

“No-nonsense information on antenna fundamentals, basic wire antennas, special antennas (such as the sloper, DDRR, Beverage, folded unipole), beam antennas, 160M antennas, tuners and SWR bridges.” — L.B. Cebik, W4RNL (SK)

“I can recommend it wholeheartedly, 100% plus. It is a true learning experience and the Amateur Radio Community should be grateful that such a book exists.” — Kurt N. Sterba, K5KNS
    CONTENTS:
    • Feedlines • Balun • Ground Systems • Lightning Protection • Towers • Dipole • Zepp • G5RV • Windom • Coaxial Dipole Myth • Sloping Antennas • DDRR • Folded Unipole • Beverage • Vacation • Antennas • Mobile Antennas • W8JK • Yagi • Two-Element Quad • 160M Band • Receiving Loops
The book was published shortly after John’s death in 1984. He was involved in an accident with a DWI driver while on his way home from a Dallas Amateur Radio Club meeting, where he’d received an award. John used to do on-air code practice and other teaching on both VHF and HF and was a much-beloved figure. You will get a good sense of the man by reading this book, now in its second edition.

I’d been looking around the house for this book for a little while and happened to find my copy over in a friend’s shack. This is a good book to loan people who need to understand antenna’s from a real expert’s perspective.

The title, BTW, is NOT a reference to some magical antenna secret that makes antennas easy, but a comment on how you can do things one of two ways: The hard way or the Easy Way, which John’s book proves to be true.

Hints: Ladder line is a good thing, along with a decent tuner. Baluns, on the other hand, may be bad or good.

    Thursday
    Sep042008

    SWR: Bad ideas that won't go away

    Radio Amateurs should forget most of what they think they know about reflected power on their antenna feed lines and actually learn something. 

    That's not me talking, but it's the gist of a series of columns that ran in QST magazine by Walt Maxwell, W2DU (SK). What's sad is that the columns ran between 1973 and 1976 and the word still hasn't gotten out. 

    Maxwell was a lead antenna designer at RCA. We still use his famous balun design to solve antenna matching problems. His projects included space systems where any power loss in the feed line could be crippling--yet he describes successful satellite systems he built with SWRs of 4.4:1 and 9.8:1. 

    Clearly, there is something those of us--myself included--who yearn for the perfect 1:1 SWR don't understand.

    Maxwell's columns are truly enlightening:

    JUDGING BY WHAT we hear on the air, nearly everyone is looking for a VSWR of one-to-one. Question why, and the answer may be, "I'm not getting out on this frequency because my SWR is 2.5:1. There's too much power coming back and not enough getting into the antenna," or, "If I feed a line having that much SWR, the reflected power flowing back into the amplifier will burn it up," or still, "I don't want my feed line to radiate."  

    Any of these answers shows misunderstanding of reflection mechanics, and are symptomatic of the current state of education on this subject. Rational and creative thinking toward antenna and feed-line design practice has been absent for a long time, having been replaced with an unscientific and thought-inhibiting attitude, as in the days before Copernicus persuaded the multitudes that the universe did not revolve around the earth. 
    Much of what is written today about antennas is just plain wrong, including in some pretty prestigious places. For example, no matter what you hear on the air, an antenna tuner really does tune your antenna system.

    If you want to learn the real truth about Standing Wave Radio (SWR) and antenna feed lines, you need to read Maxwell's columns. They have been gathered into a 68-page collection that is available on the ARRL web site. There is a great deal of free information on that page, created by the League's Technical Information Service. However, to download the Maxwell reprint, you must be an ARRL member.

    This is a great series of articles by a master of the antenna-building craft. They deserve to be read much more widely and I am trying to help that along. Read the Maxwell articles and you can stop spreading antenna voodoo and misinformation--as I already mended my own ways.
    Thursday
    Aug142008

    The New Ham's "Antenna Phase"

    Just a quick reminder about free lunches and antennas that are tiny and efficient: Neither really exists, no matter what people tell you.

    Nevertheless, every new ham goes through a phase of trying the bend the basic laws of physics to make impossibly short antennas work wonders (and some never recover). I guess it's a rite of passage, where your enthusiasm bumps against an unwavering rule of science: Long antennas (up to a point) work better than short ones, and thicker wire beats the skinny "stealth" antenna wire all to heck.

    You want a good signal on 160 meters? You better have some real estate available because there is just no getting around  the fact that a half-wave at 160 meters is over 240 feet long. And the antenna really needs to be off the ground by a quarter wavelength, about 120 feet, for best efficiency. I don't care how big a capacitance hat you put atop a 102-inch mobile whip or even how big the coil is, you aren't doing to burn the ionosphere from your mobile at 1.8 MHz.

    The best choice for a ham new to HF is  a 20-meter dipole and a 40-meter dipole, ideally one without any tricks, like coils used to shorten the antenna. Just basic coax-fed antennas, maybe with a balun in the center.

    Why? Because 20-meters is our best all-around band, though if you aren't ever on-the-air during daylight you might not notice. (Though ask me about my midnight contact with Sweden during Field Day. The secret: Most of the path was in daylight--land of the midnight sun and all).

    Forty meters is a good nighttime band, though if space wasn't a consideration, the new HF'er would also want an 80-Meter dipole, too.

    Which brings us around to the would-be emergency operator. In a real-deal emergency, we can expect to be on 40 during the day and 80-meters at night. Sure, they run the Hurricane Net on 20 and a lot of other good things happen on 14 MHz. as well, but I am talking about reliable regional coverage, not trying to talk to your State Capitol via long path.

    I barely have an 80-meter antenna on my tiny suburban lot and, frankly, it doesn't get out very well. If I need HF during an emergency I am expecting to operate using some wire antennas we're hanging at the fire station. As for home, pending getting a no-radials vertical on top of the house, I am barely HF active,. When I am it's largely on 20-meter PSK, Why? Because most people don't run more than 50 watts on PSK and my 20 meter dipole, being shorter, is much better placed on my property.

    Almost every antenna stuck into the air by almost every ham everywhere on the planet is a compromise. I have read a fair amount about antennas over the years and the closest thing I've found to magic is--not the G5RV, easily the most over-hyped antenna in the universe--but the lowly J-Pole, which comes in so many flavors and solves so many problems--OK, the same problem over-and-over--that I'd be lost without it. Need an omnidirectional VHF, UHF or dual-band antenna? There is a J-Pole ready to meet your needs.

    If new hams could just understand that part of the "attraction" of antenna work is that you can spend your whole life and never quite get it it right, they'd end up much saner people. Better hams, too. The search for the perfect really short HF antenna is fruitless, at least in terms of high efficiency. But, any antenna that gets you on the air is better than no antenna, so have fun. Isopole anyone? I don't think so.

    Tuesday
    Aug122008

    Putting P25 Scanner Audio on the Net

    Recently, my local PD went to P25 digital radios, meaning lots of people were surprised when their scanners suddenly went dead, if they were lucky enough to have a PL tone programmed. People using older/less expensive scanners found themselves listening to the nasty roar of the digital data stream.

    One of the surprised former listeners was my wife and another was her partner, together the staff AMR Medic 90 in our town. Some of the other crews were surprised, too, when their handheld scanners also stopped hearing the cops. (I get the idea that the PD didn't tell allied agencies what they were planning to do).

    My wife had been using a commercial Kenwood talkie that I'd programmed the UHF police frequencies into. She'd often have it on while working, sometimes giving her a 2-minute lead on an incident her rig would eventually be dispatched on.

    (Two minutes can be the amount of time from when the cop says, "Send us a medic unit" until the call is actually toned-out to the rig. It really can take two minutes, which I remember from CPR class, can result in a 20 percent lesser liklihood of survival for a patient in cardiac arrest.)

    Having a radio also let them know when a scene had been secured by the police and they were clear to enter. Another two minutes saved.

    I've thought about purchasing a P25 UHF radio for my wife, though the $1,300 price tag stands in the way at present. My other option is a $500 P25 scanner, which is probably not rugged enough for daily use by an ambulance crew. The scanner is also hard to operate, at least compared to a channelized commerical radio. Turn the radio, pick the channel, and you're done.

    As I said, It's sad I can't get my wife a commercial P25 talkie.

    However, my wife's partner has a data card for her laptop PC which may provide the answer: Maybe I can send scanner audio over the Internet and they can listen to the cops that way? That has to be cheaper than a P25 radio, doesn't it?

    Only kinda.

    I already own a GRE PSR-500 P25-capable handheld scanner radio. But, I don't want to devote it to feeding audio to my Mac desktop and the world beyond. I am planning to write a long piece about this radio, but suffice to say that the longer I've used it, the less I've come to like it.

    The control head of the IC-R2500I do, however, also own an $800 Icom IC-R2500 "black box" dual receiver that I use in my office at home, sometimes with the pretty good Spectrum Manager Windows software from Signal Intelligence.

    Receiving P25 on the Icom, however, also requires a $200+ P25 decoder board, easily installed into the radio. I've been pleasantly surprised at the quality of the recovered audio.

    What I decided to do was take audio from one of the dual receivers in the R2500 and feed it into my desktop Mac and from there onto the Internet, That allows my wife's partner to use her Windows notebook (with the wireless connection when Wi-Fi isn't available) to listen to the audio from the Icom. I am using a $40 program called NiceCast to transmit the audio. It's very easy to use--just install the software, select your audio source, and you're on the air.This shot makes NiceCast look more complex than it really is.

    There are Windows programs that do the same thing, though perhaps not as easily. A challenge for any of them will be available bandwidth--carriers usually offer upload speeds that are only a fraction of the download speed. They also often prohibit servers as part of their Terms of Service. You may also have problems if you don't have a fixed IP address, though there are ways around this.

    The solution works, including right here in the office, where I listen to the audio feed on my portable as I move from room-to-room during the day. It also works in the ambulance, though it is not perfect solution since it requires the PC to be on all the time.

    It's also pretty expensive if you have to buy a radio just for this application. I'd recommend either the Uniden or the GRE P25 models as a less expensive alternative to the Icom black box.

    Scanner audio on the Internet is nothing new, but using my Mac and NiceCast made it especially easy. And it's a solution until something better--like the money truck--comes along.

    Tuesday
    Aug122008

    TAC-COMM TRC-1 Tactical Radio Carrier

    This isn't so much a review as a "heads up" since I haven't actually purchased what I am writing about. But, the ad in QST looked interesting and led me to something I am planning to recommend to a served agency I am working with.TRC- 1

    The TAC-COMM TRC-1 Tactical Radio Carrier ($59.95 and seems a tad expensive) is a metal wrap-around casing into which you mount, using your own bracket or a strap the vendor sells, a radio, power supply, battery, etc., that needs to be made more easily portable.

    The carrier is 7.5 inches across, 10.5 inches deep and the height is variable from 2.6 to 4.8 inches, giving the user the option of mounting tall gear or stacking smaller items, such as a mobile FM rig and a packet TNC.

    The picture seems to show the product pretty well,  except that you're looking at two TRC-1 mounts stacked one atop the other. The picture also shows the carrying handle and the tilt-bail, which gives the mount a nice upward slant for easy viewing.

    On the vendor's web site you can see different sorts of radios and accessories mounted into TRC-1 carriers. These include some photos of radios strapped into the TRC-1 rather than mounted to a bracket inside the carrier.


    I'm interested in these right now because I've been asked to design a couple of portable stations for an agency we're working with. Currently, they have a few portable VHF/UHF stations mounted in Pelican cases. The problem is the case doesn't really do anything for how the radio is setup once it's out of the box. The TRC-1 solves that problem and may even negate the need for the expensive Pelican cases. It ought to be possible to drop a couple of TRC-1's into a plastic box of some sort, pad as necessary, toss in some coax, etc., and be done with it.

    This looks like a good product, one I am sorry I didn't think about first.