Wormhole Newsletter January 2017

January 2017

Hello Worms

We meet at the Oakhurst United Methodist Church located at 13400 Park Blvd. I will not make this meeting. I will be at the Tampa EOC activation for the 2016 college football Championship Game. Our esteemed Vice President will preside so everyone be on good behavior 😉

Talk-in is on the Wormhole repeater and I will be monitoring the simplex call frequency, 146.52. There is a 30% chance of rain, pretty much normal.

 

*MARKET FOR $400 PREPPER RADIO?*

By Dan Romanchik, KB6NU

A couple of days ago, a reader wrote:

“I would like to know if it would be feasible to build a radio with the following features:

  * SSB operation (only SSB is required, CW would be an additional benefit)
  * 20 – 50W of power
  * Portable-friendly (lightweight, capable of operating at lower voltages from small portable batteries)
  * Low receiver current drain
  * Coverage of 40m and 80m bands. Very limited coverage is acceptable. Even channelized coverage of a few select frequencies would be acceptable.
  * S-meter

“It strikes me that there is a large market for ham radio products for “preppers,” and there has been a lot of interest in the Baofeng line of radios from that market.  I think there would be a LOT of interest in a radio that could go far beyond line-of-sight and contact friends or family hundreds of miles away.  Preppers would have little interest in contacts more than a state or two away, and no interest at all in novel operating modes.  I wonder if a radio that trims away excess features (all-mode operation, wide frequency coverage, high power output, sophisticated audio filtering) could be produced for a lot less cost than currently available HF rigs.  If so, and it was paired with a decent NVIS dipole and some General-class study materials and sold as a package deal, it could be a huge hit – Something you could tuck in a bug-out-bag, set up in the field, and use to make contacts in a reasonably local area, or set up in your backyard at home and use minimal power to operate.

“Is there a reason why I don’t see radios like this on the market, some kind of technological limitation that would make this sort of thing impractical?  If something like this was built, what kind of cost and performance would you expect?  I’m certainly not expecting any kind of detailed analysis, but even just a speculation about if such a project could be feasible would be appreciated.”

I replied:

“I think one of the reasons you don’t see radios with the feature set you describe is that more full-featured radios are already pretty inexpensive. The Yaesu FT-450D, for example, costs less than $800 and offers 100W output. The FT-817ND, which is designed for portable operation, costs less than $700. Is that too much for preppers?

“While it might seem like you could sell a radio with fewer features for less, I think that you hit the law of diminishing returns. At some point, removing features, doesn’t reduce the cost all that much. For example, removing the CW capabilities from a transceiver capable of SSB operation really doesn’t save that much because in a way CW operation is really just a subset of SSB operation. You’ll save the cost of a key jack, but how much is that? Maybe a buck or two. Having said that, it could be that the big amateur radio manufacturers are overlooking an opportunity here.”

We swapped a couple more e-mails about this. He noted, “Most preppers would probably rather buy a high-end AR-15 or several months worth of storage food for $800 than a radio.” I suggested, “If there was a catastrophic event, and you really needed to communicate, wouldn’t it seem silly to have not spent the extra $400 on a really decent radio?”

What do you think? Is my analysis a little too simplistic perhaps? Are amateur radio manufacturers ignoring a potential market?

==================================

Dan, KB6NU, is the author of the “No Nonsense” amateur radio license study guides, and blogs about amateur radio at KB6NU.Com. You can contact him by e-mailing cwgeek@kb6nu.com.

* HOW DOES COAX WORK*

Coax cable is for the purpose of transferring RF energy from the transmitter to the antenna. I have heard remarks that coax can be used as a poor radiator. Putting a tuned circuit at the end of your coax will cause this to happen.

Actually most antennas are a tuned circuit. Other than loops, it has the characteristic of a Series-Resonant circuit. These antennas do the radiating, coax does not. However, if you use discreet components (capacitor and inductor) as the antenna, will the coax radiate?

You will have a resonance like the antenna. What will be different is the Radiation Resistance. The antenna develops a Radiation resistance anywhere from 20 ohms to 200 ohms approximately. This resistance is a result of the antenna radiating. The discreet resonant circuit has a Radiation Resistance that is very low. This is not only a mis-match to the coax, but it resembles a shorted circuit. This is great for circuits in your radio, but not for a radiating antenna. However, at the same time, the coax will not become the radiator. If it does, it needs replacing.

There is a condition called Common Mode Currents or Voltages. This is when RF energy, due to skin affect will travel on the outside shield of the coax at the feedpoint of the antenna. This small percentage of energy will radiate. However, it is only a fraction of the power you put to the antenna. It mainly produces interference problems in your own station. Any antenna can develop this situation. How is this corrected? Normally a simple choke at the antenna. This could be made from coaxial cable, toroid cores or ferrite beads. I have had all of these used on my antennas with much success.

My first article is dealing with feedlines. Here it is again so you can see why good quality coax will not work as an antenna.

Many are familiar with Ladder Line. Two wires in parallel from the transmitter to the antenna. If the 2 wires are spaced very carefully with little variation, one side will be of a positive value (voltage or current) and the other will have a negative value exactly equal. The 2 RF fields cancel each other. This does not take away the RF energy, but keeps it from radiating into the atmosphere and follow the wires. In affect it makes a very high resistance to the atmosphere and a low resistance along the Ladder Line.

The draw back with Ladder line is it is affected by nearby objects. Something close to the Ladder Line will unbalance it. Therefore coax was developed to reduce that problem.

Coax is doing the same thing as Ladder Line electrically. The center conductor has one polarity while the shield has the opposite. The same principal of cancellation is taking place. The shield is not really a shield in that RF is contained inside of it. There is just as much RF energy on the shield as the center conductor.

Due to the physical shape of the coax, the shield can be kept at a zero voltage in respect to your grounding. So if you had an RF volt meter you would in theory measure 0 voltage from the shield to your grounded installation such as radio chassis, tower or mast, walls of your home and so on. Now a nearby object has little affect on the balance of the coax.

At times this balance can be disrupted slightly. The result is RF feedback, interference to other electronic equipment, common mode currents or voltages, higher than normal SWR readings and more. The problems with coax are not severe, just at times a bit challenging.

73,

Ralph WD0EJA

BILAL CO.

*THE Q OF AN ANTENNA SYSTEM*

By Ralph WD0EJA, Bilal Company

What is the “Q” of a circuit? Q means quality factor. In a circuit or antenna it is a consideration of the reactances (X) and the pure resistance (R) of the circuit.

An antenna is a tuned circuit at the end of the coax or feedline. The design and size of the components affect the Q of the circuit.

The higher the Q, the narrower the bandwidth or frequency response the circuit has. The lower the Q, the wider the circuit reacts.

Q is affected by amount of pure resistance a circuit offers.

To get an idea of the Q, it should be measured at the exact resonant point of the antenna or circuit. At this point, either the inductor or capacitor value need to be known. Then, it can be looked up on a reactance chart as to the amount of reactance or resistance it offers at the resonant frequency. It will be the same for either component.

The Q equals the reactance value in ohms divided by the series resistance of the circuit. Q = X/R What does this mean?

In a series resonant circuit, if X = 350 ohms and R = 5, then the Q = 70. This will mean that a current of 1 at resonance will drop to .1 in only 8% deviation from the resonant point. At this point the loss is 90% of the current that would be at the resonant point.

Does this mean the antenna is a poor radiator? No, at the resonant point it may be good, but a small deviation would mean loss.

Antennas that have lower Q’s and wider bandwidths will have more resistance to give it the lower number. It will also increase bandwidth. Does this mean an antenna with a wider bandwidth is less efficient?

Not always, to get an idea of what Q is doing, you can liken it to the energy passing over the conductor of the circuit the amount of times as the Q. Therefore, if the Q is 10, it passes through the conductors 10 times before radiating. Does this hurt performance?

Maybe, to determine resistance, you just do not measure the ohm value of the wire. At RF (HF) the energy only uses about .0006 inch of the conductor diameter due to “skin affect”. This drastically reduces the amount of conductor it uses. If this amount of conductor develops 5 ohms, then it is like 50 ohms with a Q of 10.

Measuring Q and efficiency can be quite involved and obscure. There are antennas with very wide bandwidths that are very efficient. This is not due to high resistance in the conductors.

Therefore, it is not a good analysis to determine if an antenna performs well by a “Q” value it measures. There are other factors beyond the scope of this article and me too. The bottom line is, are you being heard and are you hearing?

73,

Ralph WD0EJA

*SAMSUNG NOTE 7 TO BE DISABLES REMOTELY*

 

INFOPackets by John Lister on December, 13 2016

Samsung is to remotely block the controversial Galaxy Note 7 phone from recharging. It’s an attempt to persuade users who’ve hung on to the potentially-exploding handset to return the device for a refund.

The phone was officially recalled by Samsung after reports of handsets overheating and causing burns, and in some cases catching fire. While Samsung is yet to release an official report into the causes of the problem, independent analysis suggests the phone’s thin design put too much stress on the battery.

To date, around 93 percent of the Note 7’s sold to the public have been returned for a refund and made their way back to Samsung. The problem is that the remaining seven percent equates to around 175,000 handsets. Even if some of those are currently with retailers or in transit, that’s potentially tens of thousands of handsets still being used.

Samsung’s latest move is to issue a software update that prevents the phone from recharging. The idea is that the handset will quickly run down and become useless, stopping people from continuing to operate it. The phone will continue to work while connected to a power outlet through a charger, but the battery won’t top up.

However, the way Android device updates works means that in the US at least it will be up to cellphone service carriers to send the update to phones. Three of the major carriers have scheduled the update with T-Mobile planning a release on December 27, AT&T on January 5 and Sprint on January 8.

Controversially Verizon says it doesn’t plan to issue the update. It said: “We will not push a software upgrade that will eliminate the ability for the Note7 to work as a mobile device in the heart of the holiday travel season. We do not want to make it impossible to contact family, first responders or medical professionals in an emergency situation.” (Source: verizon.com)

Measures in other countries have varied. In the United Kingdom the software update will allow charging but only to 30 percent of the battery’s capacity. In New Zealand, however, carriers have agreed to shut off cellphone service to the device completely. (Source: samsung.com)

 

*NEW RANSOMWARE: SCAM TWO FRIENDS TO UNLOCK YOUR PC*

INFOPackets by John Lister on December, 14 2016

A new form of ransomware offers victims the chance to escape the release fee by fooling two friends into paying up instead. A security expert likened it to a malware version of a pyramid scheme.

Traditionally ransomware involves malware getting onto a computer and then encrypting all files, with an on-screen message demanding the victim pay a fee to regain access. It’s unknown what proportion of people pay up, but some big organizations such as hospitals and police forces are known to have paid the fee in the past, rather than lose sensitive data or access to control systems.

The new variant is dubbed Popcorn Time. It has no connection whatsoever to software of the same name that allows people to use the Bit Torrent file sharing system to easily view Hollywood movies without having any technical knowledge (or any desire to question the file’s copyright status).

Bounty Encourages Shady Behavior

As with other ransomware, Popcorn Time has a release fee. In this case, it is one unit of the virtual currency Bitcoin, equivalent to around $778 at the time of writing. That’s just a little over the average ransomware demand, a figure that has risen steeply this year. (Source: channelweb.co.uk))

The twist is that there’s an alternative to paying up. The Popcorn Time instructions claim users can instead get a custom link that carries a reference code and, when clicked, will attempt to install the software.

Tactic Preys On Good Relationships

The idea is to pass on the link to other people such as friends, family or colleagues in the hope that they’ll be more likely to click on it than a message from an unknown contact. According to the instructions, if two other people get infected by the malware through the custom links and go on to pay the fee, the original victim will get their files back free of charge. (Source: theguardian.com)

There’s no evidence yet of how many people have tried to take up this offer or if the scammers really do give out the reward for passing on the link. It’s worth remembering of course that as well as being ethically horrific, spreading malware to try to gain the reward may well break local or national laws.

 

*CLUB MEETING*

Talk-in is on the Wormhole repeater system.  For those coming to the meeting who cannot hit the repeater we will be monitoring 146.520 simplex, the national calling frequency. We will keep an eye peeled for you. We will take advantage of the cooking facilities with an after-the-meeting Social and wormdog luncheon.

*CLUB NETS*

Check in on the club net Thursdays at 1930.  442.625 + with a 146.2 tone or the 2M side at 146.850 – also with a tone of 146.2.  We are always looking for volunteers to be the net control operator.  Anyone interested, talk to one your club officers.

*LOCAL NETS*

MONDAY

1730 147.030 + Receiver sites and tone info http://www.qsl.net/wd4scd/

St Pete Yacht Club ARC St Petersburg

1830 147.060+ no tone St Pete ARC daily net St Petersburg

1900 144.210 USB CARS, vertical polarization Clearwater

1900 147.135 +146.2 Zephyrhills ARC Zephyrhills

2000 147.165+ 136.5 Brandon ARS from Brandon

2000 50.135 Pinellas ARK Pinellas County

2030 NI4CE system EAGLE Net, NTS traffic net, NI4CE system

2030 145.450 Pinellas ARK Pinellas County

TUESDAY

1830 147.060 no tone St Pete ARC daily net from St Petersburg

1900 50.200 USB 6M net Brandon ARS

1900 28.450 WCF section net Clearwater

1900 NI4CE system WCF Section VHF ARES NI4CE system

1930 145.170 & 442.4 both pl 156.7 Pinellas ACS net Clearwater

1930 444.900 +141.3 Sheriff’s Tactical ARC Tampa

2000 NI4CE system WCF Skywarn net NI4CE system

2000 147.105+ 146.2 Tampa ARC net from Tampa

2000 28.365 USB simplex Brandon ARS

2030 NI4CE system EAGLE Net, NTS traffic net NI4CE system

2100 28.465 USB 10/10 net from Orlando

WEDNESDAY

1830 147.060 no tone St Pete ARC daily net from St Petersburg

1930 52.020 simplex Suncoast 6’ers from St Petersburg

1930 NI4CE system WCF Section Digital Info Ne NI4CE system

2000 147.105 146.2 Greater Tampa CERT net from Tampa

2000 146.97- 146.2 Clearwater ARS from Clearwater

2030 NI4CE system EAGLE Net, NTS traffic net NI4CE system

2100 NI4CE system Tampa Bay Traders Net non-affiliated

THURSDAY

1800 146.52 simplex Hillsborough ARES/RACES North Tampa

1830 147.060 no tone St Pete ARC daily net from St Petersburg

1900 444.750 +146.2 Fusion net from Tampa

1930 146.850- & 442.625+ both pl 146.2 Wormhole from St Petersburg

1930 146.6385 -127.3 Lakeland ARC from Lakeland

1915 224.660- no tone St Pete ARC from St Petersburg

2030 NI4CE system EAGLE Net, NTS traffic net NI4CE system

FRIDAY

1830 147.060 no tone St Pete ARC daily net from St Petersburg

2000 147.360+ pl 127.3 METRO ARC Friday Net from St Petersburg

2030 NI4CE system EAGLE Net, NTS traffic net NI4CE system

SATURDAY

0830 3.911 (7.281 Alt.)+/- QRM WCF Section HF Net from Pinellas County

1830 147.060 no tone St Pete ARC daily net from St Petersburg

2030 NI4CE system EAGLE Net, NTS traffic net NI4CE system

SUNDAY

1830 147.060 no tone St Pete ARC daily net from St Petersburg

1930 NI4CE system WCF Section Net NI4CE system

2000 147.550 simplex 550 Simplex Net Pinellas County

2030 NI4CE system EAGLE Net, NTS traffic net NI4CE system

2100 144.210 USB Clearwater ARS vertical orientation

*FOR SALE / WANTED*

Anyone having something for sale or who might be looking for an item let me know.  I will not print phone numbers or email addresses unless specifically told to since this newsletter might end up on the web.  The exception is when I get the information off the web.  If you are a member of the Wormhole then you have all the information you need on a club roster and if you are not a member  .. why not?  OK, if you are not a member you can contact me at the email address at the end of this newsletter, I will give you the information to contact the person involved.

FOR SALE, 13 element, 14.5 ft 220 beam. Wormhole property, $20, contact Bill AG4QX or any other officer. Free to any Wormhole member or other club. Pickup at Bill’s house.

 

*HAMFESTS*

2017

January 28 DeSoto County Hamfest, Arcadia, Turner Center Exhibit Hall, 2260 NE Roan Street, Talk-In: 147.075 (PL 100), contact Dougb Christ KN4YT at 863-990-2507. The website at http://desotoarc.org has no information yet

February 10-12 Orlando Hamcation, Central Florida Fairgrounds, 4603 West Colonial Drive, Tickets $13 in advance, $15 at door. Talkin 146.4760 – no PL or D-Star 146.850 -, all the information at www.hamcation.com or call 407-841-0874

February 18 Brooksville Hamfest, Sand Hill Scout Reservation, 11210 Cortez Blvd., talk-In 146.715 – no tone, contact John Nejedlo WB4NOD, 813-838-5432, website is http://www.hcara.org/.

February 25 West Central Florida Section Technical Conference (3rd Annual TECHCON), Sarasota, Sarasota Red Cross, 2001 Cantu Court. Looking for presentations and displays. For info see http://www.arrlwcf.org/ or contact Darrell Davis KT4WX at kt4wx@arrl.net

May 27 WormFest 2017, Pinellas Park,  FREE,  Freedom Lake Park, 9990 46th St N, southeast corner of US 19 and 49th Street, 33782.  Park opens at sunrise, hamfest from 0800 till…  Talkin on 442.625 + or 146.850 – both with a tone of 146.2.  For a map and directions see http://www.TheWormholeSociety.org .

 

*OTHER EVENTS*

Last full weekend January Winter Field Day, http://www.spar-hams.org/index.php

Late January Gasparilla celebration

March/April MS Walks

March/April Mass Casualty Exercises

Late April Southeastern VHF Society Conference, http://www.svhfs.org

Late April Walk For Babies (was March of Dimes)

Late April Florida QSO Party

Mid-May Annual Armed Forces Crossband Test

Mid May MS 150 bike ride

Mid-May Florida Hurricane Exercise

Late May Wormfest

Early June Museum Ships on the Air

Fourth weekend in June Field Day http://www.arrl.org/contests/announcements/fd/

July 3/4 Midnight Run in Largo

August International Lighthouse/Lightship Week

October, 3rd weekend JOTA, Scout Jamboree-on-the-AIR

Early December ALS bike ride in Walsingham Park

December, first full weekend Ride & Run With The Stars in Fort DeSoto Park

December, Second full weekend Tampa Bay Hamfest

*YOUR WORMHOLE OFFICERS*

Bill AG4QX is President and editor of this newsletter, Vice-President is Mike K4ZPE,  Treasurer is Jim KD4MZL, Paul KA4IOX is the Secretary, Dee N4GD is the Repeater Trustee and Neil W4NHL and Mike K4ZPE are our club webmasters.

*YOUR WORMHOLE REPEATERS*

442.625 +  PL 146.2

146.850 –  PL 146.2

The Wormhole repeaters are both now dual mode Yaesu DR-1X. FM analog as always and now Yaesu Fusion, a C4FM/FM digital mode. The repeater crew updated the software on May 3, 2016.

The Wormhole website is at: http://www.TheWormholeSociety.org.

West Central Florida Section website:  http://www.arrlwcf.org/.

The ARRL website is at: http://www.arrl.org/

This newsletter is written for The Glorious Society of the Wormhole, an ARRL affiliated amateur radio club located around the Seminole section of Pinellas County Florida. Anyone wishing to be added or removed from The Glorious Society of the Wormhole mailings please write to me at the address below and thy will be done.

73,

Bill Williams

AG4QX

ag4qx AT arrl DOT net

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