Tech Net Notes December 10, 2009

We had a very short net on this evening. No questions (until the end) and very few comments.

ke5cub, Lee, made the announcement that he has a CD full of Ham Radio manuals that go back to 1928. If anyone needs a manual for an older radio, Lee will run you off a copy for no charge. If you can reimburse Lee for his ink/paper expenses, that's fine, but not required or expected.

If you have a need for a manual for a piece of ham gear, contact Lee, ke5cub, by phone at 245-0788, or by email at ke5cub@cox.net.

kk5edd, Ed, checked in and said he's trying to decide between an auto tuner and a manual tuner. He would like to know what the pros and cons are. Especially he's interested in folks who may have found advantages of one over the other. This will probably be a topic for our next TARC Net, January 29th.

See you on Wednesday, January 13th!

Tech Net Notes November 27, 2009

After enjoying Thanksgiving Day, and it being a holiday weekend for many, we convened the November, last-Friday-of-the-month, Tech Net on TARC's repeater system at 9:00 PM.

kd5und, Travis, checked in with a problem he's been having with a hum in his radio only when he uses an electret mic. When he changes to a dynamic mic, the hum goes away. When he changes radios, but keeps the electret mic plugged in, the hum is there. He's checked his grounding, changed power supplies, checked his mic shield and tried other radios and had narrowed it down to a problem with the electret type microphones only. Since it happens with other electret microphones, it probably not a problem with the microphones. When the hum is there and he places his finger on the radio chassis, the hum goes away. So the question is "What is the microphone picking up, and from where, and how can it be corrected?"

kd5und, Travis, also mentioned that he's got fork lift batteries for his back-up power and is using a UPS charging circuit out of an old APC unit (with bad batteries) to keep them charged up.

wb5mxo, Guy, checked in and mentioned a w3ff BuddiPole he saw mounted on a three wheeled bicycle. This was in response to an earlier e-mail communique.

n5kh, Will, suggested to kd5und, that he try lifting the ground pin to the AC house wiring to see if there was something coming in on the ground.

ke5wph, Andrew, said that he's getting prepared to put in a 45 ft. Rohn 25 tower and has a question, "What is the optimal guy tension for the guy wires. Regarding Travis' problem. Maybe an RF choke on both positive and negative.

kd5und, Travis, suggested to ke5wph that he tighten his guys to 3 - 6 inches of deflection on the guy cable.

n5kh, Will, mentioned an RF choke as well. Also, does putting a battering in parallel with the power supply filter the noise out? Are there cables running parallel to something that might induce a signal into the power cable. kd5und, Travis, mentioned that the problem does go away with a battery, but that he has not put the battery in the power circuit. It sound like it's either in the power supplies of the AC service to the shack.

kd0cdk, Don, suggested that the 2008/9 ARRL Handbook has a lot of information on noise problems and troubleshooting them. Also he suggested taking the house out of the power circuit with power going only to the shack to see if maybe there is something in the house wiring letting something in. If, during isolation, the problem goes away, you know it's something in the house. Also, have you tried installing a capacitor from the mic positive to ground? Also, are your computers on when you have this problem? kd5und, Travis, answered that he's turned the computers
off and the problem persists.

kd5njr, Scott, suggested that you can check the noise on the AC line with an oscilloscope by taking a few turns around the hot and connecting it to the 'scope probe. That ought to induce enough voltage to see what's going on without putting too much current into the 'scope.

n5kh, Will mentioned that Travis may want to keep an eye on the UPS charging system for his fork lift batteries as many of those UPSs are designed for a particular duty cycle, and the fork lift batteries might exceed that level.

kd5und, Travis, replied that he will start doing that and monitor the output voltage. He said he's been using that system for about 6 months with no problems yet and the system triggers it's alarms whenever he changes the load too greatly.

n5kh, Will, said that the idea to use the UPS charging system is a great idea.

End of Net

Continental Code vs. Morse Code

According to w2csl, Bob, what we now know and use as Morse Code was originally called "Continental Code". It was an upgrade from the first Morse Code that was developed in an effort to standardize code with other countries.

The picture shown above was found by David, my most recent AT&T U-verse installation tech. Dave responded to a call for help from me after I moved my computer back into our "office" from a recent remodeling fiasco.

We had AT&T out about two months ago to put in another Internet drop. The tech that responded then added a line to a temporary location in the house. He did not wire it into the system, but told Jim, our tile installer, how to wire it in when we're ready. So when we moved the computer from the office into our den, we just had to splice in the new wires. That tech told us that we could just leave it that way when we moved back to the newly tiled "office". When we did move (eventually) back into the office, we could not get the internet back up.

David showed up and found that the, now unused, temporary wiring still hooked to the system acted like an antenna and allow enough noise into the system that the signals would not sync in. Our 3-in-one package left us without TV, internet, and phones. All David had to do was disconnect the unused pairs and the system popped back up.

David noticed some of the HAM paraphernalia in the office and we talked a little about it. David mentioned that he had found a handwritten table of Morse Code vs. Continental Code inside a 1901 printing of Longfellow's Poems, brittle from age, which he bought at a garage sale.

David scanned the old document and e-mailed it to me. That is it pictured above.

A teeny bit of code history.



ke5omv
Don

Tech Net Notes October 30, 2009

We didn't get very far into the tech net before the repeater went Ka-bloooey. During a transmission the repeater timed out...and that seemed to have done something to disable it's operation.

Thanks to those who tuned in...or at least, tried to.

Sorry, we'll give it another shot:
November 11, 2009 - 146.910 - 7:00 PM
November 27th, 2009 - 147.045, 443.850 & linked system - 9:00 PM

Enjoy the weather!

Don
ke5omv

Tech Net Notes October 14, 2009

On this one we started off again without a topic.

w5ydl, Dan, changed all that with a question: He said that he's planning on putting up a 6 meter dipole and working 50.125. He asked "Is there anyone who can tell me a little bit about working 6M?

(NOTE: See kd5njr, Scott's comments on this by scrolling to the bottom of this post and clicking on "comments".)

kb5vdb, Ron, checked in and reminded us of Paul's upcoming deployment to Afganistan. In addition Ron passed on the recent new of a husband, wife, and son who died while installing a ham radio antenna. It fell into a 13,000 volt transmission line. Apparently they were not hams, but putting it up for a friend.

ke5yoo, Mike, mentioned that kd5njr, Scott's loop antenna was at about 50 feet. Orientation was the bigger question, with vertical giving you a possibly lower take-off angle. In addition Mike mentioned that ke5otq, Dennis is going to make some 2M loops.

kk5edd, Ed, said that he has been doing PSK31 on 20 meters lately and has plans on mounting an HF antenna onto his 5th wheel, if he can get a good idea of a good way to do that.

ke5yoo, Mike, mentioned that height-wise, one wavelength off the ground is good, but with 6 meters and greater, the higher you get the antenna, the better.

kd5cny, Tom, suggested to kk5edd, Ed that screwdriver antennas usually work well on motor homes and such. He also said that a long wire, hung from trees works better with a tuner. He mentioned that another option might be a vertical.

kk5edd, Ed asked, "Is the vertical you're speaking of, a multi-band?"

kd5cny, Tom answered, "If you have a tuner, the vertical should be able to take care of working multi-band." He added, regarding antenna height, "It's good to get the load of the antenna over the 1st wavelength." He said that between the 1st and 2nd wavelength, there's not much noticeable difference... abpve the 2nd wavelength, there's a lot of difference. He also mentioned that kd5cuz, Craig, has had a problem working his Garmen GPS with his 10 meter radio. He said that when Craig turns on his 10 Meter radio, the GPS quits working. It wont receive satellite data. Turn the 10M radio off, and the GPS starts working again. The radio does not have to be transmitting, just turned on. No problems when he fires up on 2M or 440mhz.

kb5vdb,Ron says that it sounds like the IF is interfering with the GPS and causing the
signals to the GPS to cancel out.

ae5ln, Paul, said that he (also) has been messing around with PSK31. "Where's a good place to pick up a signal?"

kk5edd, Ed answered, "14.070 on 20 meters".

ae5ln, Paul said that on 20 meters he locks up his computer.

kd5cny, Tom, suggested that Paul check the shields on his coax jumpers.


End of Net

Tech Net Notes September 25, 2009

ae5ft, Gene, suggested that "The 2 Meter Band Plan" be a topic for the Tech Net. So tonight this is what we put forth. The following information was taken from an ARRL Repeater Director with a little info mixed in that I found on the net:

Frequency Spacing
States East of the Mississippi - 20 kHz
States West of the Mississippi (excluding Texas) - 15/30 kHZ

Popular Simplex Frequencies Nationwide
146.49
146.505
146.520 National Calling Frequency
146.535
145.55
146.56 (in Texas)
146.58

Simplex
146.4 - 146.58
147.42 - 147.57

SSB
144.200 Calling Frequency
144.20 - 144.275


ke5cub, Lee, was the first to check in with a question. The question was, "What's the difference between resonance of the antenna and low SWR, and how to they affect each other?

We had a few check-ins but no takers until ad5pe, Jay, offered an explanation to Lee's question. I wish that I could repeat Jay's answer, but I did not have my recorder set up and my note-taking failed me. With that in mind I will try to encapsulate that which I can remember. I will do this with the help of:
http://www.radio-electronics.com/info/antennas/basics/resonance.php
http://qsl.net/g3yrc/antenna basics.htm


To start off with, resonance is a vastly overrated concept. But what is antenna resonance?

An RF antenna is a form of tuned circuit consisting of inductance and capacitance, and as a result it has a resonant frequency. This is the frequency where the capacitive and inductive reactances cancel each other out. At this point the RF antenna appears purely resistive.

The capacitance and inductance of an RF antenna are determined by its physical properties and the environment in which it is located. The larger the antenna or more strictly the antenna elements, the lower the resonant frequency.

The magnetic field that your antenna puts out will produce an electric current on any metal surface that it strikes, however if the metal that the signal strikes has a length relation to itself, the current will be much stronger on the object. If the object that the magnetic wave strikes is 1/2 wave length, 1/4 wavelength, or 1 full wavelength, then the induced current will be much higher than if the signal struck an object that was not some appreciable fraction of the wavelength of the signal. An antenna is "tuned" at for an exact wavelength. For that exact frequency that antenna is resonant. Every antenna has at least one exact resonance point.

Antenna resonance is the frequency, in MHz, where the antenna is in a state of electrical balance, which is determined by the length of the antenna.

SWR (Standing wave reflected) is the phenomenon that exists when power which initially was sent into the antenna is reflected back toward the radio. The SWR is measured in a ratio, for example 1.5:1 (or 1.5 to 1). How much power gets reflected back into the radio is dependent on the impedance of the radio/coax/antenna. If it's matched perfectly, the power reflected will be near zero (or said another way, an exact match, 1:1).

The impedance of the antenna is a function of the frequency being transmitted and the point at which the antenna is resonant.

Though your antenna may be resonant at a particular frequency, It is more important that the SWR not surpass levels that would be harmful to your radio. You can talk fine on an antenna that is not very resonant, but a high SWR can burn up the
"finals" in your radio.

ke5cub, Lee, added that "Resonant means that the antenna vibrates at it's assigned frequency. Keep the SWR below 2.1:1."

ae5jz, Tom, checked in and said that on his "waterfall" on PSK 31, there is a signal line less than 7 cycles wide at various places along the band, without modulation. He asked if anyone had any ideas about what that was.

k5bbm, Brian, asked, "At what frequencies do you transmit PSK31 on 2 meters?

kk5edd, Ed, suggested that it may be (according to his reference material) that 144.144 for vhf and 432.2 for uhf.

I don't recall who it was, but I believe someone suggested that the 7 cycle line on Tom's waterfall may be associated to some of Tom's equipment.

With that there were no more check-ins, and the Net ended.

Tech Net Notes September 9, 2009

There was no topic for the Tech Net this time. Instead... we had rain. Lots of rain. Even though Tulsa proper did not get buckets full, Northeast Oklahoma received steady rain for the day and somewhat previous.

w9nbc, Steve, came on during the intro to report street flooding on Memorial from 101st to 111th. Though the rain was settling down a bit, the water, the rain, and the lightning was on our minds.

w2csl, Bob, was the first to check and posed two questions:

1. Why are we called "Hams"?
2. How many Hams checking in tonight have been commercial operators, licensed by the FCC?

kb5vdb, Ron, came on to take a stab at the first question. He mentioned that he had heard that it may have had to do with Hiram Percy Maxim, who is considered to be the "father of Ham radio". Ron said that his initials, HPM , may have been the source from which HAM was derived, although there is no known evidence to say that is definitely the case.

w9nbc, Steve, checked in and said that he had been FCC First Class licensed with radar.

ad5jl, Bob, said he remembered something in QST being written about the "ham" moniker, but doesn't recall exactly what was said. Bob was also licensed through the FCC as First Class. In addition he posed the question, "How do you check to insure that the safety ground lug in a receptacle in your house is wired correctly, going back to a ground rod?

wb5uuw, Earl, checked in and mentioned that he was FCC Licensed First Class. Regarding checking for a ground he said that first you verify that you have a physical ground (rod) tied to the breaker box. He mentioned that the ground should be connected to the ground bus in the breaker box. If that is the case, go to the receptacle and check the AC+ against the Safety ground socket for 110 (120) VAC. If it check's OK, check the return (wide part of the socket) against the Safety ground socket for 100 (120) VAC. If no voltage, that's good. You can then check for continuity between the return (wide part of the socket). There should be continuity.
It is important to mention here that you follow that sequence. Check for your voltages before you check for continuity...and...(of course) do not check for continuity between the AC+ (narrow part of the socket) and the Safety ground.

NOTE: Understand? If you've got voltage between two points and you try to check for continuity, it may melt your meter into your carpet...and it's so hard to get melted plastic out of your carpet. Plus it may blow up your meter and send the indicator needle through your forehead and into orbit. Those indicator needles are hard enough to replace as it is!

ke5lnn, Dave, said that he has one of the line testers (plugs into a receptacle and analyzes voltages and grounds) and that it's served him well. Dave also made the point that the the piece of equipment that your connecting to a ground needs to be opened up to make sure that the chassis is wired to the ground of the AC power cable into the unit.

ke5otq, Dennis, added that there are ground fault detectors that can be purchased which will do the trick. Regarding the origin of "Ham" he suggested that it may have related back to one of the first guys licensed.

Linking Repeaters

Linking repeaters is done all over the country. When one repeater is linked to another, whoever keys up on one, can now be heard on both. This can extend the range of a radio.

And if several, well placed repeaters are linked together, the ability to communicate over the total area of all the involved repeaters can be a valuable asset to communications (especially emergency, public service, and disaster related communications). Most of us are familiar with TARCs UHF network which serves much of Eastern Oklahoma with repeaters in:

Tulsa 443.850
Manford 442.000
Tahlequah 442.225
Cavanal Mt. 442.250
Muskogee 443.100
Stillwater 444.525
Mounds 444.600 (having some problems at this time)
Ponca City 444.700 (having some problems at this time)
Bartlesville 444.975 (having some problems at this time)
McCalister 444.975
Edmond 443.250
Fayetteville, AR 444.925
Decater, AR 442.850
Ketchum 444.875 (temporarily out of service)
Daisy 444.400

Also I just found that there seems to be a linked system that covers much of Western Oklahoma. This was pulled from the internet at: http://www.srh.noaa.gov/oun/skywarn/.

"The NWS Norman SKYWARN Radio Network should be thought of as a "liaison net" during severe weather. It is not intended to collect individual spotter reports, but rather to serve as a collection point where local spotter networks can relay information to the NWS. In other words, the individual storm spotter should use their local frequencies and procedures to report severe weather to their local organization. When the local spotter net receives a report of severe weather, a liaison from that group relays the report to the National Weather Service via the liaison net. Amateur radio operators at the NWS Office will also provide radar information and the latest warnings and statements to the liaisons, who in turn pass the information on to their local spotter network.

Spotters and anyone else interested in keeping track of severe storms are encouraged to monitor these frequencies, but traffic should be limited on the liaison net. You should attempt to report severe weather to your local spotter groups instead of on these frequencies."

Much of the following is taken from http://repeater-builder.com/rbtip/repeaterlinking.html


There are other areas around the country that have linked systems as well. For example:

Alabama - 29 repeaters

Arizona - 22 repeaters

West Texas (Davis Mountain)

Cactus Intertie - icludes parts of California, Arizona, New Mexico, Nevada, Utah, Colorado, & Texas.

Colorado - 15 repeaters

South Carolina - 4 repeaters

Illinois/Indiana

Tennessee

Target Link - Parts of Pennsylvania, Maryland, Virginia, and West Virginia.


The "Remote Base" type link system is the most common because of its simplicity and low cost. Basically a second radio (even an old hand held or mobile rig) is connected to a repeater that you want linked to another. It uses that new radio as if it was a regular "user radio" on the other system. The "link" radio need not be duplex because of the way the link and repeaters are configured. Naturally the link (remote base) radio will need to be on the same band, frequency, split, and PL as the repeater you are linking to.


ae5ft, Gene, had the following information on IRLP as a mode for linking radio systems.

http://www.irlp.net/

The aim of this project is to reliably and inexpensively link amateur radio systems without the use of RF links, leased lines, or satellites.

The IRLP uses Voice-Over-IP (VoIP) custom software and hardware. Coupled with the power of the Internet, IRLP will link your repeater site or simplex station to the world in a simple and cost effective way.

IRLP operates a worldwide network of dedicated servers and nodes offering very stable worldwide voice communications between hundreds of towns and cities. All this with unsurpassed uptimes and the full dynamic range of telephone quality audio.

kd5cub, Lee, asked if anyone had any information on the FT-2000 100 watt with pep upgrade. If anyone has information on this equipment please contact kd5cub.

wa5vxi, Manuel, asked if other repeater systems use modes other than rf to connect up between repeaters (in particular, maybe using the internet).

ke5okt, Jim, mentioned that the newly running 430 repeater in Sapulpa was recently connected to another repeater (I believe in the OKC area) via Echolink (which is via the internet) but that it is not normally linked up. It can be done (and is likely being done in other places).

kd5guu, John, said that he regularly checks into an Echolink repeater on a Railroad Net on Tuesday evenings that is run out of Wisconsin. He mentioned that is a very operational and effective system.

ae5ft, Gene, added that our (TARC's) system is rf to rf, but IRLP is a very valid and easy to operate system for internet linking. He provided the IRLP info a few paragraphs up.

ke5zcz, Mike, announced that he is a scout leader and that the scouts are selling popcorn, as a fund-raiser, and that those who may run across a popcorn-selling scout, please consider buying some to help support this very worthwhile organization.

End of Net -

Tech Net Notes July 31, 2009

Here lately the Broken Arrow Amateur Radio Club has been doing some work on their 145.450 repeater located in the Bixby/Leonard area. In addition TARCs 443.850 repeater was just repaired today after a few weeks of low audio.

Also, in the recent past, RCWA's repeater got hit by a surge or a lightning strike and was off the air completely. As an interim solution, ww5wow Larry, used a repeater set up he had that would receive your signal and then re-transmit it on the same frequency. Your transmission would be stored in memory and then re-transmitted. You would hear, along with everyone else, what you just said. And this would all occur in simplex mode. The repeater would be listening and repeating on the same frequency. It made for slower transmission rates, but it did accomplish the goal of boosting a signal beyond it's limits (in most cases).

As an extension of that repeater work going on in the Tulsa area, we will be talking about repeaters here on the Tech Net tonight.

kb5vdb, Ron, sent in this explanation of repeaters:

A ham radio repeater is basically a radio system that receives the weak signal from mobile and portable radios, and re-transmits the signal on a different frequency at a much higher power level. Repeaters are usually mounted on TV and Radio broadcast towers, tall buildings, high hills, or mountains to extend the range of the station as far as possible.

The basic components of a repeater are the receiver, the transmitter, the controller, the power supply, the feed-line, the antenna or antennas (whichever applies), possibly a power amplifier, and a duplexer (cans) if one antenna is used.

There are two ways to construct a repeater:

1. Mount a single antenna as high as possible, and use it to both transmit and receive. Feed it with a single feed-line after running the signal through the duplexer. The big problem with this design is:

a. The cans are expensive, ornery, and delicate.
b. They have to be properly tuned, which requires a lot of EXPENSIVE equipment and a very knowledgeable technician.
c. They have a tendency to drift and become un-tuned.
d. They cause a lot of signal loss. (You also have to figure in feed-line loss for long runs.)

2. Mount separate transmit, and receive antennas as high as possible, separating the antennas by at least 100 feet. The big problem is expense of two antennas, two feed-lines, and of course, having to place the antennas at different levels on the antenna support. The big plus is no cans (and subsequently no loss through the cans) and if the repeater operator can locate the repeater box as close as possible to the antennas, you get most of your signal out.

There is a little delay every time that you key up, with some delays being substantial. Always allow a second or two before you start to talk.

The controller, by the way, allows a radio to become a repeater by allowing the transmitter and receiver to both operate at the same time.

ac5jm, Jerry, checked in and mentioned that there are a lot of variations to repeater set-ups but that Ron's explanation was a good summary. The on-frequency repeater, ww5wow's, is especially good for an emergency or disaster situation. It also might have an application on 10-meters since there is only 100 khz bandwidth, but nearly impossible to do without a dual site antenna. It's a good back up to have stashed away in case you need it.

The low audio problem on the 443.850 machine was a level problem. The site owner changed the temperature in the equipment room which allowed the pots to go out of tune.

ae5ft, Gene, asked. "Regarding the cans that have to be tuned: How does that fit in with repeater operation?"

k6jxy, Paul, answered, "The cavities keep the transmitter from getting into the receiver. They operate as a set. They are usually a six-pack on a set."

ke5okt, Jim, said, "I still have a KendeComm repeater that I'd like to get running on VHF. If anyone has any information on this brand or type of repeater, please e-mail me at jim@mounds.org.

ae5mn, Hank, asked, "Is there circuitry that separates the signal by detection of signal direction?"

ac5jm, Jerry, answered, "The receive side of the duplexer filters out the transmit and vice versa. The cans are manufactured for a specific range of frequencies and have to be tuned to be resonant to the frequencies used.

ke5zcz, Mike, asked. "Which repeater is better to have, one antenna/duplexer or two antennas, for a base repeater and what is the price range?"

kb5vdb, Ron, answered, "If you have a tower tall enough to separate the antenna by about 100 ft. and can get the radio close enough, you don't have the duplexers and the problems associated with them. If you don't have a taller tower, it's best to go with a duplexer. As far as costs... in the neighborhood of $5000.

ke5vas, Tim, asked, "Are there other linked repeater systems that cover as wide of an area as this one? How is the care and maintenance of the other repeaters handled?

kb5vdb, Ron, answered, "Maintenance is taken care of by the areas clubs, volunteers, and whatever funds they can raise. There was a linked system called Buffalo. It's not around anymore.

ac5jm, Jerry, added, "There are a lot of different clubs that have joined because of the affiliation with the National Weather System. The linked system is laid out to support the NWS. Ther are a few exceptions to this: Stillwater, Edmond, and Ponca City.

Tech Net Notes July 8, 2009

On the day of the Net we had a bit of unexpected rain. For most of us, rain, and especially lightning, affects our radio activity. To reduce my exposure to lightning, I usually will move my radio operation to a battery powered radio hooked to an attic antenna. The base radio gets unplugged from AC. I physically unplug my power supply from the wall. In addition, I unscrew the PL-259 connector from the back of the radio and let it dangle, not allowing the antenna connector to touch anything. I do not ground the plug.

My question, to those who check in tonight is: What do you do with your radio equipment during a storm?

Ron, kb5vdb, said that he didn't know if there is anything you can do to protect yourself from a lightning strike. Air is the best insulator that we know of, and lightning passes through air easily. He mentioned that he unplugs from the AC source and may hook to a magnet mount antenna. He mentioned that he had a friend that was hit by lightning while driving a tractor. The lightning hit him in the head and came out of his foot; he lived.

The story below was found at: http//www.dailycognition.com/index.php/2007/04/27/story-of-a-man-who-was-struck-by-lightning-7-times.html.

"US Park Ranger Roy C. Sullivan from Virginia holds the record for the person most struck by lightning - and living to tell the tale. Between 1942 and 1983, Roy has the dubious distinction of being struck by lightning seven times. He was known as the Human Lightning Rod.

The first lightning strike in 1942 happened as he was working in a lookout tower and the lightning bolt shot through his leg and knocked his big toenail off.

In 1969 while he was driving along a mountain road a second strike burned off his eyebrows and knocked him unconscious. Another strike just a year later, while he was walking across his yard to get his mail, left his shoulder seared.

He was standing in the office at the ranger station in 1972 when lightning set his hair on fire and Roy had to throw a bucket of water over his head to cool off. A year later, after his hair had grown back, a lightning bolt ripped through his hat and hit him on the the head, setting his hair on fire again. It threw him our of his truck, knocked his left shoe off and seared his legs. A sixth strike hit him in 1976 while he was checking on a campsite, injuring his ankle.

The last lightning bolt to hit Roy in 1977 happened while he was fishing. It sent him to the hospital with chest and stomach burns.

Roy Sullivan was never killed by lightning - he committed suicide while in his 70's in 1983 reportedly distraught over the loss of a woman."

Mike, ke5yoo, added that on a direct hit, there's not a lot that you can do. As long as you have a good solid single point ground at your antenna, then you shouldn't have a problem. As the voltage increases from a surge, the potential may rise in all of your equipment, but your equipment needs to be unplugged. If you get hit by lightning in another part of the house, and the lightning finds another path through your equipment, you'll have damage.

It stands to reason that your exposure to lightning, or subsequent power surges resulting from lightning, is related to the exposed inputs into your equipment. For most of us there are two avenues that allow this. The AC input to your equipment is one and the antenna input to your equipment is the other. If you have computer or other devices connected to your equipment, they may also provide an avenue.

The ARRL has a two-part article that addresses Lightning Protection. The first part is found at: http://www.arrl.org/tis/info/pdf/0206056.pdf . The second part can be found at: http://www.arrl.org/tis/info/pdf/0207048.pdf .

Tim, ke5vas, mentioned that American Power Conversions has a number of Uninterruptable Power Supplies that provide a level of protection against surges, particularly power drops. He said that he is at the end of a line and suffers a lot of power drops.

APS UPSs are available from office supply stores such as: Office Depot, Office Max, and Staples. They can also be found at electronics stores, like Best Buy.

More can be found on APS at: http://www.apc.com

Paul, ae5pb, suggested the use of Polyphaser as a source for protection. "Various amateur catalogs (AES for sure) stock some Polyphaser products. Electronics supply houses generally stock a more comprehensive inventory. You can find bunches of them on the internet. These are the industry standard - USACE uses tons of them in radio and also remote sensing applications. I'll bet I've written purchase orders for over a hundred of them. Their lightning protection handbook is the best out there.

Hoffman boxes are NEMA (National Electrical Manufacturers Association) spec enclosures. Though this is a specific brand, it's kind of like kleenex or band aid, and has come to mean any such box.

AES sells one that will hold Polyphaser copper single point ground panel, with in/outs for two coax lines. I'm going to use one with three coax ports, with the Polyphasers on the ground panel inside."

Polyphaser's website is located at: http://www.polyphaser.com .

Dave, ke5lnn, said that he has extensively used Polyphasers on his rig on every coax. He had the electric company put in a surge suppressor on the other side of the meter. During a storn he unplugs everything that has a wire in it. The idea is that the coax comes into a connector outside with a copper plate. He said that he's also heard that you can use a glass insulator, like a bottle to put your connector into inside. But that could create a glass bomb!

Note: I couldn't find anything on the internet that mentioned the use of glass insulators for isolating your PL-259 connector. If anyone knows anything about this, I'd be interested in hearing about it. I imagine that unless the glass is pure with virtually no air pockets, then the heat from a lightning strike could possibly cause the air in the pockets to expand, quickly, causing a "glass grenade", much like what Dave mentioned above.

Hank, ae5mn, mentioned that his exterior antenna gets disconnected during a storm and that in the future he intends to disconnect the power as well.

Ron, kb5vdb, added that most antennas are DC grounds anyway, but that Hank's, being a j-pole, will not be.

NTS - National Traffic System

In this post we will attempt to explain NTS, what it is and what it does. The information here was taken from: http://www.arrl.org/FandES/field/nts-mpg/ and loosely paraphrased. My deepest apologies!

What did I just hear?

Do you remember the game where you would pass a message around a group of folks standing in a circle? One person would whisper a message into the ear of the next person, who would then whisper the message into the ear of the next person, until it made it all around the circle and back to the originator. Oftentimes it was humorous and sometimes amazing to see how badly the message was maligned during it's trip around the room.

In that instance, the entire group of people was like a conduit and each person was an interface that had to re-transmit the message as if a link in this chain of communication. And, as said in the proverbial analogy, "the chain was only as good as it's weakest link". It was a fun game and well illustrated how perverted a message can get when relayed down numerous "links".

In an emergency situation communication becomes supremely important and is often viewed with solemnity and reverence. When lives hang in the balance, the time for frivolity has passed, and the time for focus and sobriety is at hand. To be a link in the chain of emergency communications becomes a serious matter. If you have the opportunity to be a link in that chain, at that time, you will likely want to be a strong link.

This is much of what NTS does. It organizes, trains, prepares, and tests the links of communications. When the time comes, you just revert to your training, instead of trying to re-invent the wheel. If done correctly the information you pass along may make a difference in someone's life.

The ARRL manages and operates the National Traffic System to assure a continuing and reliable structure to handle formal message traffic in the US. Though it may not be as "lay-back" as a comfortable ragchew on an informal net, there is great value to be had knowing that you can pass traffic effectively and efficiently. When time is of the essence, there may be no valuable substitute for effectiveness and efficiency.

We, as amateur radio operators, have many resources at our disposal for communicating. Not only to we have a number of bands available, but we also have a variety of modes available, such as voice, CW, SSB, and digital, and we have a multitude of delivery systems, horizontal, vertical, NVIS, or reflected off satellites. When an emergency occurs, we often have the means to relay vital information.

"The Fingerbone's connected to the Wristbone, and the Wristbone's connected to the Armbone"

So how do we all connect to each other in order to facilitate effective and efficient emergency communication? It all starts at the local level with ARES. The Amateur Radio Emergency Service. When you affiliate with ARES, you become a link in this recognized chain of communication.

Local ARES Nets link to
District Nets who link to
Section Nets and Traffic Managers who link to
Region Net Managers who link to
Area Net Managers who link to
NTS who links to
ARRL HQ

Of course, it may be a bit more complicated than that, but that is a general idea of how it works.

Tech Net Notes May 29, 2009

On this evening's net the topic was NVIS. After a brief description of Near-Vertical Incident Skywave (much like the post below this one), we opened the net for check-ins.

ke5okt, Jim, checked in with a question. He has a KendeCom, model KRP-5000 repeater and can't find much information on it. He asked if anyone has information on this brand, such as how to find parts and documentation. kb5vdb, Ron, mentioned that aa5v, Steve, may have a repeater of that brand in his garage, and may know something more about them. Steve is a member of TRO and may be contacted through the club. If anyone has information they think Jim might be able to use about the KendeCom repeaters, he can be contacted at jim@mounds.org.

n5tda, Rex, mentioned that he has a G5RV up at about 25 ft., which would be less than 1/4 wavelength and would fall into the NVIS category. He mentioned that he was not able to get within the 500 mile skip zone at that height.

ke5lnn, Dave, asked if NVIS is in wide use by any particular amateur radio groups. In addition, Dave has a TE Systems 1412G, 2 meter amplifier. He says it works fine on two meter but doesn't work on 70cm. He has heard of a mod that can be done to allow it to work on 70 cm and wants to know if anyone knows how to install that mod. w5ydl, Dan, says he also has one of those amplifiers and that he too would like it to work on 70 cm, but doesn't know how to install the mod. Dave mentioned that he may be able to reach someone at TE tech support who can help.

ka0oxn, Rich, said that he had a 160M installed at about .o4 wavelength height that was good out to about 400 miles. He also had a 40M installed at 10 ft. that was good to about 300 miles.

na5dw, Dan, said that he would like to find a way to get his HF signal from Fairplay, CO to Denver, CO, about 90 miles. He tried a dipole hooked up to his truck's tailgate, on one end, and to a signpost on the other end, about 3 ft. high, 20M or 40M, and couldn't quite make the trip.

ae5ft, Gene, said that n5fem, Steve, was talking into the Dallas, Texas area on 40M, on the NVIS dipole mounted at 5 ft. at the last Route 66 event in Chandler Park. He also mentioned that he uses an NVIS antenna every day to check into the Oklahoma Sooner Traffic Net, which is a part of the National Traffic system Net. His antenna, he calls an "extreme" NVIS antenna, which is a G5RV mounted along the top of his wooden fence at about 6 ft, with about 10 ft. of wrap on each end, fed with about 30ft. of twin-lead and a short piece of coax. He says that he is about 90% effective getting into the net on 80M. He says he's worked both coasts during the Route 66 Contest where folks were trying to make contact with him as a Route 66 station. So it may not be all that good of a test, coast to coast.

ae5mn, Hank, mentioned that this might be an HF solution to his problem of finding something that would fit in with his neighborhood covenants.

kk5edd, Ed, said that he's in the process of building an NVIS antenna, from plans of Dr. Carl Gellenik, n6vng, with two 38ft. elements and then at 90 degrees from them, two 25 ft. elements. The design calls for a threaded center conductor on a SO-239 plug, which Ed is having trouble finding/fabricating. Ed would appreciate hearing back from anyone who might have information on how to find a threaded SO-239 center connector such as this.

ae5ft, Gene, mentioned also that in NVIS applications, we have to look at the maximum usable frequency. That is the maximum frequency that will bounce of (versus penetrating) the ionosphere. That "maximum frequency" can depend a lot on conditions, sunspot activity, and etc. Gene mentioned that 40 M is "iffy" on NVIS, which may explain na5dw's, problem making a 90 mile trip in Colorado. The other thing Gene mentioned, is that when you're looking at 80M NVIS, that's what most dipole installations are, to at least some degree. Few of us can afford to construct 120 ft towers for your dipole!

ke5und, Travis, checked in and mentioned that he's used NVIS technology inadvertently. He understands the principle but now knows what to call it. Travis asked if NVIS relates more to angle of take off. ae5ft, Gene, answered that yes, angle of take off is one of the parameters that NVIS defines. Travis mentioned also that this is probably why he can make it in to Albuquerque, NM but can't quite make the trip into Arizona.

NVIS (Near-Vertical Incident Skywave)

What is NVIS?

Near-Vertical (meaning somewhere around straight up) Incident (an event, something that happens) Skywave (the reflecting of a signal, usually RF, off the ionosphere). Think of it as pointing your antenna straight up and having the signal "shower" down all around you.

NVIS - compared to what?

Think of the two modes of antenna orientation with which we are most familiar: vertical and horizontal.

Vertical - line of sight, groundwave propagation

Horizontal - long-distance, skip

'Splain yourself!

If you can talk about 50 miles on a vertical antenna predictably, and on the horizontal plane you can pretty much count on shooting over most stations that are closer than 500 miles away, NVIS is a method that you can use to fill the gap (skip zone). NVIS allows you to have more reliable communications with stations within a 100-200 mile range.

Great! How do I do it?

You do this by directing your signal straight up. Rather than pointing your beam directly overhead, you can do it the easy way. Cut a dipole to the desired frequency, and install it less than 1/4 wave above ground. Last September at the Route 66 event in Chandler Park, N5FEM, Steve, installed one at about 5 feet and did very well with it. By installing it closer to the ground, you are using the ground as a reflector. In a sense, it becomes an upward pointed beam.


Putting One On Top of a Hill

Well...yes you can...but...with valleys generally containing more moisture than hilltops, often-times you get a better reflection in a valley. And, after all, you're directing your signal upward, so a valley may be more advantageous, especially if you're trying to avoid detection (military applications).


What Bands?

Generally speaking, 160M, 80/75M, 60M, & 40M is where you can use this system most effectively. As we have learned, the higher frequencies will tend to penetrate the ionosphere more, and reflect off the ionosphere less.


Why bother?

In an emergency or if you have friends within the dreaded skip zone (200 miles), this allows us to have fairly predictable communications. Skipping on the horizontal plane is not that predictable, and where it is predictable, may not be that useful. On the vertical plane, line-of-sight may not cut it. You often need more. NVIS fills the gap between the two.

You can read more about this at: athensarc.org/nvis.asp

Tech Net Notes May 13, 2009

Without much of a topic, the net began with a string of check-ins from Ron's, kb5vdb, group. There were storms looming around Oklahoma and Ron kept an eye on things for us with regular updates.

ke5yoo, Mike, started off with a question regarding a problem he was having with RFI. On 10 meters, Mike has been getting into his (and worse yet, his neighbors') wireless phones. Mike wanted to know if that was a common problem (on 10 meters) and if anyone had experience with fixes for that kind of problem. ke5omv, Don, stated that he had a similar problem on 10 meters, on with his computer, when he keyed up the computer locked up.

w2csl, Bob, asked what frequency the phones were on and mentioned that (older) 50 Mhz phones are near a harmonic of 10 meters. ke5yoo, Mike, responded that the phones were in the 2 Ghz range.

kb5vdb, Ron, suggested that K-COM makes a line of telephone filters that are sold through AES and can probably be found in AES's online catalog. In addition, the higher he could get his 10 meter antenna, the better for reducing chances of nearby RFI.

ae5mn, Hank, checked in and mentioned that his Fong Dual-Band Twin-Lead J-poles are doing well. He mentioned that he was surprised at how well his smaller Fong antenna was doing mounted in the attic. He said he enclosed it in a protective sleeve normally used around fluorescent tubes. It's a thin, clear tube of plastic with caps. Hank has it installed near a gable in the attic. Though he normally has problems getting into the 910 repeater, with that set-up, he seems to be doing fine.

ke5wga, Ray, checked in and gave a report on his GP9 look-alike, the Tram WP 1481. Ray just installed it last week and has it about 25 ft. in the air. Ray mentioned that he felt he did fairly well moderating the Saturday Night Simplex Net with it. He said he was able to talk to all that he heard.

ke5yoo, Mike, was asked what kind of antenna he was using that caused the RFI with wireless phones. Mike responded that it's a G5RV junior.

wb5uuw, Earl, cautioned to make sure that the coax, where you hook up to the balun is 35 ft. long. The ladder line should be about 17 ft. long with a 4:1 balun.

ke5uiu, James, said that he has a G5RV (full size) with 45 ft. of ladder line, a 1:1 balun, a 100 ft. of coax and can talk well on it. He would like to be more directional and is planning on a rotating dipole for sometime in the future. Being in Porum, he can hit the 910 repeater with his 4-element beam on low power. To get to Bartlesville on 2-meter he has to bump the power up to 25 watts.

kk5edd, Ed, questioned if anyone had built an NVIS, 4 radial, antenna. ae5pb, Paul, came back and mentioned some positive experience he had with it, through the military and that two legs are cut for 80 (moderator: I think!) and the other two are cut for 60 meters.

ke5icx, Tom, checked in from a Broken Arrow motel room. He is visiting the area and heard the net.

End of Tech Net

(Note: If you have any corrections or additions to these notes please leave them in the comments section. I did not take as good of notes as I would have liked, so if there are other cogent points that were made (or that you would like to now make)that I missed, please let me know.

Another contest station - these guys are serious!

http://www.qth.com/w0aih/

Tech Net Notes April 24, 2009

We opened up the net at around 9:00 p.m. and were immediately plagued with problems, kf5rd, Pete, had trouble linking things up through his HT and had to tap ae5ft, Gene, for some help. Then as we began talking and asking for check-ins, the QRM went crazy. It sounded to me, at first, like the squelch tail was incredibly long on the VHF machine and that someone was trying to get into a linked UHF machine and wasn't making it. So it would take several seconds (maybe 10-20, it seemed) for things to settle down.

But we pushed on.

The topic was logging software. I had posted several logging programs on this blog with their web address and cost just a few days ago. (It is two down from this one.) So most of the programs that came up were mentioned on the blog already. That being said, the big question was, "What experience have you had?" My experience was limited, but there were several folks who had good info to share.

It went like this:

kc5eqj, Scott, mentioned that the University station in Fayetteville uses N3FJP logging software. He had used it but was interested in hearing about any software that might be better suited for personal use. ke5lnn, Dave, said that he had recently been looking at G8PUT, which was recently reviewed in QST. ae5ft, Gene, added that the N3FJP software is excellent logging software, especially for contesting, and the cost is reasonable $50 for all the options. He agreed with ke5lnn, Dave, that G8PUT looks like it has some great features. He added that XMLOG is free, and the one he uses, MicroLog is only $10 and includes an up-to-date logbook.

ke5lnn, Dave, added that he just downloaded G8PUT, and has started using it. He said that he's been contacted by the company that an update is already in the works. One feature he likes is that you can push a button and see if you've ever made contact with the folks you just logged in.

ke5zcz, Mike, liked the sound of the G8PUT mentioned in QST, but thought he might need something simpler to start out with.

ae5ft, Gene, further mentioned that if simple is what you want, try eQSL. It is an on-line logging system and offers a whole set of electronic awards. It allows you to make and send electronic QSL cards as well. But if you want a program that you download into your machine and can use, independent of the internet, MicroLog is simple and has the added feature of the callbook data.

wa5vxi, Manuel, mentioned just using a Microsoft Excel spreadsheet. He also said he was aware of Ham Radio Deluse having a logging function along with it's radio control software package.

kc5zqm,Doug, said that he didn't have a lot of logging experience, but when he did log, he used a form that he designed with AutoCad. He also suggested a future Tech Net Topic of "Mobile Installations and Operations". (Note from moderator: That sounds like a great topic to me!)

ae5ln, Paul, had a question, "How does logging software track a frequency?" ae5ft, Gene, clarified with an explanation that new radios sometimes have a feature that allows a plug in the back of the radio to cable up to a plug to your computer, with the radio supplying the usable data to the computer. Older radios often lack that feature.

kc5ert, Jeff, mention that he bought a copy of MicroLog at Green County Hamfest this year and is looking forward to trying it out on Field Day. He likes it because it works, "stand alone" without the need to be hooked up to the internet. He said he had heard that if you have an old copy of MicroLog, you can download the current call book information. ae5ft, Gene, mentioned that Jerry (the owner of the software company) mentioned that he does not have that available for downloading and that you must buy a new CD to get the callbook (only $10 at hamfest, $12 over the net).

End of Tech Net

Tulsa Amateur Radio Club Meeting - k3lr

Last Tuesday TARC's program was a visit from Tim Duffy, k3lr. Being a relatively newly licensed ham (almost 2 years now), this was one of the most interesting programs that I've seen. Tim brought a powerpoint/video presentation that showed and explained his involvement with Amateur Radio, and in particular, contesting.

For those of you who are not much into contesting, you would still have loved this presentation. Tim is passionate about ham radio. His enthusiasm and his ability to communicate to folks like me (semi-technical) and folks who are very technical made for a truly enjoyable HAM experience.

Pictured above is one (that's right, only one) of his many antennas. His radio room is 30' x 30'. What goes in all that space? Check out k3lr.com ...he's got pictures...lots of pictures.

Logging Software

Below is a list (not complete, I'm sure) of some of the logging software available. As you can imagine, with computers, logging can be made easier for those who wish to use it. If you make a lot of contacts, and you want to document those contacts, logging software can assist you in that endeavor.

eHam.net has review of 27 logging programs at: http://www.eham.net/reviews/products/27,
where they provide a listing of the various programs, any reviews they have received from users, a numerical rating, and the Manufacturer's Suggested Retail Price.

Gene, ae5ft, came away from Green Country Hamfest with two copies of "MicroLog" last March. He was a MicroLog user before, so he jumped at the chance to buy the program and callbook for $10 from Jerry, wa0h, http://www.wa0h.com,. As it turns out Gene won one of the hourly drawings and...guess what the prize was...yep, a MicroLog CD, just like the one he had just paid $10 for.

Gene says that the MicroLog software has some shortcomings, but overall, works fine. The real-time only logging feature uses the call book data base. He says the built in maps are great. Other features include band plans, prints QSL cards and/or labels, grid square, CQ Zones, DX country lists. It also has import/export functions. But best of all is the callbook information. Gene says, "If I buy a copy from Jerry at every Green Country Hamfest, then I have up-to-date callbook every year for $10."

Thanks for the great information Gene!

Here's that list of some of the software available.

Microlog--http://www.wa0h.com--$12 (includes callbooks)
Ham Radio Deluxe--http://ham-radio-deluxe.com/--free
Amateur Contact Log--http://www.n3fjp.com--$19
Logger32--http://www.logger32.net--$49
Winlog32--http://winlog32.co.uk--free
DX 4 Win--http://www.dx4win.com--$90
Shortwave Log-http://shortwavelog.com--free (I think)
Log Window--http://www.scoincsoftware.com--$4.96 per yr.
DXKeeper--http://www.dxlabsuite.com/dxkeeper--free
XMLog--http://www.xmlog.com--freeware
Klog--http://www.kreso.com/klog--free
59+Log--http://hamradio.idealog.net--Shareware $25
CQLog--http://www.cqlog.com--$39
AALog--http://wareseeker.com/free-rz4ag-analog/--free
DXbase2007--http://www.dxbase.com--$99
DXtremeStationLog--http://www.dxtreme.com--$89
Easylog--http://www.easylog.com/world.htm--$89
B-log--http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=10531
SwissLog--http://www.icap.ch/--free

On-Line Logging

ae5ft, Gene, also has contributed this information on two Online Logging systems:
The first is:

eQSL - available at: http://www.eqsl.org

"This is a free log online. I used this as my very first log file when first licensed. You can enter contacts online and they are stored for you. Others can add their contacts on their log and when the two match, you have a "verified" contact. You can take this as far as you want. The site offers its own set of eQSL awards. You can design on online qsl card that is sent electronically when someone logs a contact with you."

"Currently the OMISS net recognizes the eQSL confirmation for their awards and CQ allows the use of eQSL for their awards, too."

"No fabulous features other than the electronic contact verification and automatic logging of awards."

"Well worth checking out."

The second is:

The Logbook of the World: http://www.arrl.org/lotw/

"The Logbook of the World is supported by the ARRL and is much more formal than eQSL. You must sign up and your call certified to enter your logging information. Not useful for single contact logging, but really good for uploading bulk files or contest files. When two stations have matching information, a QSL is logged and verified. These are used to confirm contacts for WAS and other ARRL awards. This logbook is used worldwide and is well recognized and supported by the DX community.

Everone should be a member if doing any work on HF or for anyone working gridsquares or DX activity.

73, Gene"

Cross-Band Repeat Addendum

Radios That Support the Cross-Band Repeat Feature

Alinco
DJ 586
DR 610
DR605
DR635

Yaesu
FT-8100
FT-8800
FT-8900
FT-5100
FT-5200
FT-847

Icom
2720
2820

Kenwood
TM-732
TM-V7A
TH-79
TM-V71
TM-D700E

Tech Net Notes April 8, 2009

Cross Band Repeat

What is cross-band repeat?

This is where a radio is set up to receive on a frequency on one band and then repeats what it hears on a frequency on another band. In most cases, when the cross-band feature is activated it works in duplex mode. That means that whatever it hears on one frequency, it repeats on the other. To be activated, it is necessary to program both frequencies into the radio and then activate the feature.

Application? For example, if you can't make it into a VHF repeater from your HT at home, if your home station has the capability, you can set it up to listen (and talk) to your HT on UHF, and to relay your transmissions onto the VHF repeater's frequency. With that activated you can walk around the house (or anywhere within range of your home station) and get into the VHF repeater through your HT.

In the above example, your home station has become your own personal repeating relay station. Of course, anyone transmitting on the same UHF frequency within range of your home station will be able to get in to the VHF repeater as well.

It should be noted here that you do not necessarily have to "repeat" into a repeater's frequencies. This can be done on simplex as well. For example, if you want to enjoy an evening of grilling on the patio at the same time your favorite Saturday Night Simplex Net is being run, you can now do that without moving your equipment outside. You can program in the Simplex frequency and the HT frequency into your home station, activate the feature, and from the comfort of your patio listen to and check in to the Simplex Net. Burgers never tasted sooo good!

If your mobile unit has the capability, it can act as a relay station as well. For example, you park your car on a hill where it can get into your favorite repeater and now you can talk through your HT to the repeater via your car's radio as you're hiking around the hills and valleys within HT range of your car.

If you operate the cross-band repeat station using a battery as a power source, realize that the radio will be transmitting anytime anything is heard on either frequency. If your power setting is at the highest level, and the frequencies are fairly active, you may run the risk of overheating your radio and/or running down the battery. For this reason it is recommended that you use the lowest power settings possible (especially on your HT).

ke5wsi, Ray, wanted to know if anyone knew how to set up his FT5100 for cross-band repeat. He doesn't have the manual for it anymore and needs help figuring it out. w5okl, Richie, mentioned that he has seen radios that will do cross-band repeat that don't have that feature documented in their manual.

ke5yoo, Mike, mentioned that he read that there are some ID requirements that may need to be met while in the cross-band repeat mode. ke5omv, Don, said that he had seen the same issue addressed in an article on the internet, and that it was suggested in the article that even if you are just "listening" while in cross-band repeat mode, it is necessary to identify every 10 minutes. The automatic code identifier can be annoying to other operators, so it's best to do it through voice transmissions.

ke5wga, Ray, asked if radios must be "dual receive" or said another way, have the ability to receive two separate frequencies at one time, in order to cross-band repeat. ke5lnn, Dave, replied that yes, radios must have the "dual receive" feature.

ke5lnn, Dave, added that he uses the cross band feature when he can't be in his shack for a net. He also cautioned that you need to make sure you turn the cross-band feature off when you're not using it. Sometimes it can get hung up, so you need to monitor it's use.

kc5uoq, Larry, said he's never used the cross-band feature, but a friend at work would use it inside the building where they worked to cross-band to the radio in his jeep. It worked great.

ke5ubr, Hank, said that he has been working with his cross-band repeat and that he had it disabled at this time because he did not want it hanging up the repeater. He has had that occur on occasion, and doesn't want to cause problems for the net. He sets his power to low on UHF and to high on VHF.

ke5mxh, Don, said that he had a visit from wb5mxo, Guy. Guy dropped by to show Don how to tune his amplifier. He added that on the Oklahoma City Tech Net, to reduce problems from doubling, they suggest to start your transmission with "This is..." then un-key, listen for others who may have keyed up, and then if clear, continue on with your transmission.

kc5qgq, Dan, suggested that when in cross-band repeat to set your squelch at minimum, then set your power at the minimum you need to get in, they adjust your squelch back up. Also, to reduce hanging up the transmitter, he suggested to the the transmission time ("tx time") to a shorter time, which would produce a shorter squelch tail.

ke5swu, James, asked if anyone had experience using Ham Radio Deluxe with a Yaesu FT-897. w5ydl, Dan, answered back that yes he has used it and that it works great. He added that you can completely control your radio with your computer.

kf5acd, John, asked what would be a good radio for cross band repeat. ke5omv, Don, suggested the Yaesu FT8800 and mentioned that Kenwood and Icom both have radios that cross-band repeat. kc5qgq, Dan, suggested the Yaesu FT-8900 quad-band radio and the Kenwood 733A as being radios he had good experience with. He added that the Kenwood's manual doesn't say anything about it, but he found out how to set it up from another ham and that it works.

ka5tro, Tony, said that the Alinco DR605T is an older radio, but that the cross-band feature in it worked very well.


Added Note: I ran across a website that explained the procedure that Ray would use to activate the Cross-Band Repeat on his Yaesu 5100. It is: http://www.radiomods.co.nz/yaesu/yaesuft5100.html

Tech Net Notes March 27, 2009

In the above diagram, the interface device, RigBlaster, is pictured in the middle toward the bottom (where the microphone is plugged in). This came from wb5mxo, Guy, via ke5lep, Stan. Thanks to both!

PSK31

The topic for the March 27th edition of the Tech Net was PSK31. We were lucky to have Guy, wb5mxo, sit in and be our "Elmer".

To start off, Guy gave us a brief summary of what PSK31 is: He compared it to teletype over the ham frequencies. Typically, in today's world, four items are needed to send and receive in the PSK31 mode:
1. A radio transceiver
2. A computer
3. In interface device between the two
4. A program for the computer

Since most of us have computers and radios, usually all we need is the interface device and the program. The interface device that Guy likes is the "RigBlaster", but Guy advised us that there are many available that will work and some you can build for yourself.

Once you have the interface device, you just need software. Guy mentioned here that there is a ton of software available, some free, some for sale. He said that much of the free software works just fine.

One issue that came up while in QSO with w5ydl, Dan, was that he had heard that even when the bands are dead, PSK31 gets through. So that even in poor conditions contacts can often be made. Guy, more or less, confirmed that by saying that there is a drop off at night on some of the bands, but daytime contacts are usually possible and often abundant.

In additon Guy mentioned that a lot of information can be found regarding PSK31 on wm2u's page at http://www.qsl.net/wm2u/psk31.html

Not only does wm2u describe how PSK31 works, but he has schematics for interface devices and mentions the software and other products available to make contacting easier. In addition, he has a lot information on contesting, if you're in to that sort of thing (as many PSK31'ers are!).

Also Guy furnished another link that has info on PSK31. It is http://www.mymorninglight.org/ham/psk.htm

Guy made a particular point in driving home two important issues.
1. Don't over-modulate your signal. That's a big no-no in the world of PSK31 in that is uses more bandwidth that is needed and practical, and it interferes with other PSK31 signals. You just don't need to do it, and it botches things up for others.
2. PSK31 is used on specific frequencies on each band on upper sideband only.

w5okl, Richie, related that he had downloaded some free PSK31 software and found a website (somewhere in Europe) that allows you to operate a receiver and listen in on PSK31 traffic. He was able to get a "taste" of this mode of communication without hooking up an interface or even using his radio. It will be necessary to look around internet for the site, but it turned out to be a great way to check things out.

kc5rbh, Jeff, asked if you can do this as licensed only as a Technician. Guy said that it is possible but, practically speaking, the bulk of the PSK31 traffic will be found in the General class frequencies.

w5okl, Richie, provided the following three address to sites that he has visited to "listen in" and control the radio in the PSK31 mode.

http://websdr.ewi.utwente.nl:8901/

http://www.globaltuners.com/

http://www.remotehams.com/

Welcome To the Tulsa Tech Net Blog

NOTE: THANKS TO AD5PE, JAY, FOR SENDING THE PIC OF THIS ANTENNA. TOWER HEIGHT IS 330 FT. THE 80M BEAMS ARE AT 300 FT. AND THE 160M AT 270 FT. TOTAL WEIGHT IS 80,000 LBS. THE 160M IS 3 ELEMENTS, 12.9 dBi GAIN, 26 DEGREE TAKE OFF ANGLE. THE 80M IS 5 ELEMENTS, 15.7 dBi GAIN, 12 DEGREE TAKE OFF ANGLE. FRONT TO BACK RATIO FOR THE 160M IS 20-30 dB AND 20 dB FOR THE 80M.



The purpose of this blog is to support and promote the 2 meter Tech Net hosted by Broken Arrow Amateur Radio Club's w5bbs repeater on 146.910 on the second Wednesday of the month and Tulsa Amateur Radio Club's w5ias repeater on 145.110, and 443.850 and the linked system, on the last Friday of the month.

The purpose of the Tech Net is to focus discussion of technical issues related to Amateur Radio. A big part of that is to provide a forum in which inexperienced (or less experienced) Amateur Radio operators may ask questions and thereby receive advice.

So if you have a question that you’ve been dying to get an answer to, you can do a “shout out” on Tech Net Night. Or feel free to leave us a question/comment on this blog in any one of the posts.

Tech Net Notes March 11, 2009

The net started with a query that wb5vst, Ben, relayed to me on the March 10th RACES Net. He was interested in knowing how to go about hooking up several radios to the same speaker.

With four or so radios in his car and speaker space sparse, having the radios share a speaker would help him manage the available space. What he wants is the ability for one speaker to carry the signals from four radios all at the same time (as if you have four radios on). So a switched speaker system would not necessarily work.

On the RACES Net, kd5und, Travis, suggested a mini-mixing board. A mixing board would tend to isolate the signals from each other and send them to one speaker output.

To start things off on the Tech Net, ke5yoo, Mike, relayed some information he discovered that related to the last Tech Net on February 27th, regarding coax. There was an issue of how to use various types of coax. Mike mentioned that RG58 is not a very good coax to use. It's only good for about 150 watts of power on VHF. In addition, Mike told us that as the frequency goes down, all coax types tend to work better.

ke5zol, Casey, checked in and had a question about the performance of his station. He said that yesterday evening, he copied the RCWA Net quite well, but could not make it in from about 31st and Harvard. He is talking on 10 watts with a magnet mount antenna on a piece of sheet metal in his garage.

kc5wsi, Ray, replied that Casey's equipment performance was understandable and that it is really performing well. Getting into the RCWA repeater with that set up, that far away, is not likely. In fact, Casey is doing well to get into the BA repeater as well as he is. ke5omv, Don, agreed.

ae5ft, Gene, related to Casey that he had a similar set-up when he placed an ultra-light MFJ magnet-mount antenna upside-down on his ceiling vent. Gene went on to mention that with that set-up, at his location, he was able to get into all of the Tulsa area repeaters.

ae5fa, Rob, (regarding 4 radios/1 speaker) suggested that installing a 4 to 8 ohm resistor on the signal side of the audio line coming out of each radio and hooking into the speaker with the return lines (or shield) wired in common and to the shield side of the speaker may work to keep signals from back-feeding into the other radios.

ke5wsu, James, suggested using diodes instead of resitors.

ae4fa, Rob, mentioned that diodes would just "clip" the audio and it would not work well.

kb5vdb, Ron, said that he found a device that you can use to hook up 6 radios to one speaker in the AES catalog, but that it may not allow you to listen to all of the radios at once. The part number is NCS 3220.

wx5lib, Matt, said that he has used a commercially available product to hook up four radios to one speaker in emergency vehicles. It is called a 4-channel combiner amplifier. The website for that is: http://www.fleetradioproducts.com/htm/model301b.htm

kb5vdb, Ron mentioned that you could re-wire a quadrophonic headphone to allow for a 4-input headset.

kc5wsi, Ray, said he found the four into one device from AES and it is called an interface kit with catalog numbers 3240 and 3230.

kc5uoq, Larry, announced the Storm-spotter training in Claremore for March 17th.