August 2007
Spark LogoARRL Logo 
The SPARKGAP

Southern Peninsula Amateur Radio Klub

MEETING

Date and time: Tuesday, August 7, 2007 at 7:30 p.m.
Location: Salvation Army Building, 1033 Big Bethel Road.
Subject:  tbd

NOTE FROM THE EDITOR
This issue has a lot of pictures. That might make for problems for some. I apologize for that. SPARKGAP is republished on the ARES VA web site ( http://www.aresva.org/aresva.html ), usually only a few days after you get your personal copy. If you click on district news there is usually a link to the latest issue. Also, on the district news page, click on District 7 and find links to previous editions. Again, I want to express my appreciation to webmaster, Dan Edwards, AG4YU.

More articles and comments are needed.

There are some upcoming events everyone needs to be aware of. September 8th and 9th at Hampton's Bay Days, HPT will set up a station at the CERT booth. The following week end, September 15th and 16th, is the Virginia Beach HamFest and ARRL Roanoke Division (that includes us) Convention. See their flyer elsewhere in in this issue and visit their web site for up to date information. Finally, the following Saturday, September 22nd, a new Technician class starts. That's a busy September and will be followed by October, late November and December with their usual public service events. This is a good time for hams to get involved, there's a lot to choose from. See the District 7 in the public Service Section for some specifics.

Due to new conflicts, John, WA4WDL, will not be able to attend Tuesday night meetigs. Therefore, he felt, for the good of SPARK, he needed to tender his resignation as Vice-President. I for one will miss his comments at the meetings.

73,

Stu, N4STU
[Note: click on the BLUE callsign to send email to the editor]

The next edition will be mailed about August 28th.  Articles and comments due by August 26th.

CALENDAR contact me for specific information and to add future events
August
September
EMERGENCY RADIO SERVICES
Check the ARES VA web site at:   http://www.aresva.org/aresva.html
Knife Edge RF Diffraction:
An Experiment in UHF Mountaintop Propagation

Tom Goyne, N4NSP and Earl Evans, KE4NBX




Abstract: Typically UHF frequencies perform poorly when trees, mountains and/or man-made objects form significant RF obstructions, making them less suitable for voice and digital emergency communications. This article discusses a UHF RF diffraction experiment that provided communications adequate for simulated Search and Recovery (SAR) operations by using a UHF repeater to transmit a strong, directed signal over an intervening mountain to a mountaintop ‘incident site.’    

Key Words: UHF, Mountains, RF Obstructions, ‘Knife Edge’ RF Diffraction, Emergency Communications, SAR Operations

Background
The ability to reliably send and receive voice and data over radio waves is essential when establishing radio communications whether over a local, amateur repeater or through a Radio Wave and Laser Experimentsstatewide digital packet network. The presence of RF obstructions such as dense stands of trees, mountain peaks, and man-made objects can limit UHF radio communications particularly in the western, mountainous areas of Virginia when a signal must propagate along a phalanx of tree-lined mountain ridges. The situation is worsened if one of the radio stations is located on a valley floor or in a RF shadow next to an adjacent mountain.

Radio Wave and Laser Experiments
Experiments have shown that when radio waves are transmitted over a ‘knife-edge’ mountaintop projection, that diffraction will cause some of the signal to enter the valley or RF ‘geometric shadow region.’ [1] The same principle generally applies to laser beam diffraction when transmitted over the edge of a sharp object, such as a razor blade.
 (This photograph courtesy of ITS.) 

Experiment Parameters and Equipment
In this experiment, the authors used a mountain ridge as a topographic ‘knife edge’ to determine if UHF RF diffraction could be reliably used for Experiment parameters and Equipmentemergency communications. A 45-watt UHF repeater and radio operators were located at an actual emergency helicopter landing zone known as LZ-7. Radio operators were also located at the ROCKD mountaintop ‘incident site,’ as might be done during SAR operations for an air crash. Medevac LZ-7 was established as an Eagle Scout project and is near the crossing of the Appalachian Trail and a U.S. Forest maintained road in Rockbridge County.

Radio operators were equipped with commercial 4-watt UHF portable radios. The experiment was to determine if the radio operators at the LZ could remain in contact: 1) while at a LZ, 2) while driving along mountain roads approaching ‘incident site,’ and 3) while hiking up to the mountaintop. The complicating factor was that a mountain – or the topographic ‘knife edge’ for this experiment – was located between the repeater and the ‘incident site.’ In this photo of LZ-7, the mountain on the left, under a clear, azure sky, presented a sizeable RF obstruction in height, length, and in distance, commercial 6-element UHF yagimaking an ideal test range for RF diffraction experimentation.

A commercial 6-element, rear-mounted Maxrad® UHF yagi (10.2 dB gain) was placed ~8 feet above the valley floor and was pointed slightly upward and directly at the distant mountain ridge. A short run (~20 feet) of LMR-400UF coaxial cable connected the repeater to the antenna. The UHF yagi produced an ERP of ~360 watts with a 42 degree forward lobe. Depending on the height of the ridge or mountain, the RF diffracted signal can be 15 to 20 dB below the primary light-of-sight signal. A strong signal, nevertheless, was needed for the experiment to work. To limit potential RF exposure hazards once the repeater was turned on, no one was permitted to stand directly in front of the antenna.  (The RF field was strong enough to lock the doors on my 4x4 Ford pickup truck with the keys inside.)

Experimental Test Results
Tests results showed that when going through the 45-watt repeater at LZ-7, 4-watt portable radios were adequate to reliably communicate from the LZ to the mountaintop, as might be required during SAR operations.

On the back slope of the mountaintop ‘incident site,’ the 4-watt portable radios did not have a strong enough signal to accomplish reverse RF diffraction to reach the repeater at the LZ valley.  However, it demonstrated that the principal thrust of this experiment worked. When on the back slope, a 35-watt UHF mobile with a roof-top gain antenna was needed to reach the repeater. Even then, the signal was about half-scale with some ‘white noise.’ This indicates communications quality RF diffraction is dependent upon: 1) distance, 2) antenna height, 3) RF power output, and 4) antenna gain, preferably using a yagi or beam antenna.

As the team progressed up the mountain, they briefly encountered several areas of marked fading, presumably from secondary obstructing ridges and rock outcroppings that blocked the signal. Once they were in UHF simplex range, the repeater and the use of RF diffraction were longer necessary. Overall, this experiment demonstrated that an innovative approach to UHF communications could be used with good success on amateur and public safety frequencies.

Photo Credit
[1] Telecommunications: Glossary of Telecommunication Terms, Institute for Telecommunication Services, Boulder Colorado, 1996. www.its.bldrdoc.gov

About the Authors
Tom Goyne, N4NSP, is the newly appointed DEC7 and previously served in this position. He is a medicolegal death investigator, an EMT with Gloucester Volunteer Fire and Rescue, and a member of York County CERT.  Tom is the control operator of ROCKND on 145.730 MHz.

Earl Evans, KE4NBX, is the EC for Gloucester County and Mathews County. A master electrician of many years, Earl has installed and repaired mountaintop packet nodes in the VDEN system and helped to conduct this RF diffraction experiment. He served with the Appalachian Search and Rescue Council for 10 years, where he recovered remains from mountaintop air crashes. He has extensive experience semi-technical and technical (vertical) rope rescue and in SAR tactical public safety communications. 

PUBLIC SERVICE EVENTS

Please send me information about upcoming events and post-event articles.

Hampton Roads' Disaster Volunteer Day (DVD)
A very informative conference was held July 14th, 2007 at Liberty Baptist Church in Hampton.

The Hampton Public-Service Team coordinated the parking for the event. All the vehicles were successfully directed to the various designated parking areas. There were over 200 attendees and (I'm guessing) over 50 other event volunteers. The operators involved with parking were AA4AV Addison, AG4JE Bob, AI4OO Cindi, KC4F Chris, KE4LUJ Harold, KG4TAX Rick, KI4JZU Wayne and XYL Sharon, KI4VPI Steve, KI4WKS Greg and WD0FYV Ed. We had an enjoyable time. A special thanks is due KC4F Chris for getting, setting up and returning the white trailer. Many people toured and were impressed by the trailer during the outside demonstration time. There were also some other impressive rigs on display. Amateur Radio made a good showing.

There were many interesting sessions that provided good information.
Red Cross Disaster Assessment Training
A class is scheduled for August 18th at 9 am at the Red Cross Building on Mercury Blvd. Watch for e-mail announcements.
DISTRICT 7 NEWS
The District 7 Advisory Council (D7AC) met July 30th. All hams in District 7 are members of the council. (District 7 is the Peninsula from Hampton to James City County and Gloucester and Mathews Counties.) Here is an unofficial, edited account of the meeting, provided by KC4F.

A trailer steering committee will be (initially) Darrell (KF4HJW), Rick (KG4TAX) and Joe (KI4LXT). The committee will have a mission to organize things and propose actions to the D7AC as a whole. They will not make decisions on major issues. If you wish to be on this committee, please let KC4F or a committee member know.

There was a presentation on Public Service Events (PSEs). Besides the actual public service we are performing, PSEs do three things for us. 1) they provide the public a chance to see us involved. 2) they give us a chance to work together and get to know each other and 3) they give us a chance to practice tactical operations.

In addition to the benefits listed above, a representative of the group (D7AC) has been signing contracts for us, committing the D7AC to support events. That makes the fact that we have been receiving a poor showing at these events more significant. We really need to make as many of these events as we can.

The group voted to actively support the last three events for the year:

October 6th & 7th is Newport News Fall Festival for car parking. We will park cars both days. This event will utilize the white trailer and require 30 total operators. The Navy dive team can provide 15 and we need at least 15. D7AC normally gets a cash honorarium for its support.

November 30th is Holly Dazzle for car parking. This event will also utilize the white trailer and require 30 operators. Again the Navy dive is willing to provide half the manpower. D7AC normally gets a cash honorarium for its support.

December 1st (the next morning) is the Gloucester Holiday Parade. Same as previous years, we will provide overall float control. This operation will not require white trailer support and will only require 12 ham operators (no Navy). D7AC does not get an honorarium for this support.

The honorariums listed fund the equipment used by the D7, such as the white trailer and its contents.

The D7AC will address next year's events at a future meeting.

Future meetings:
The next meeting will be August 27th at 6:30 pm in the JCC EOC.
D7AC will begin meeting the 4th Monday every other month starting September 24th but the location is TBD.
D7AC is meeting both August and September due to the need to get things moving in the district and help get the PSEs off the ground.
DIGITAL
check the VDEN web site at  http://vden.org

The Virginia Digital Network website is located at http://vden.org and has lots of interesting info for digital users. This is from the the website.

Background and Purposee
The Virginia Digital Emergency Network (VDEN) was established on October 1, 1995 to provide amateur radio-based digital communications for supported agencies during emergencies, exercises, and other public service events.  VDEN is designed to route traffic to and from the Virginia Department of Emergency Management (VDEM) or the Virginia EOC (VAEOC) on behalf of supported Eoc’s and other agencies.  The VDEN system may also be used to send and receive digital traffic on behalf of the National Weather Service (NWS) Skywarn program.

NOTES

The Hampton Public-Service Team (HPT) is raffling radios donated by Bruce, WA8KLH, and Mike, KQ6IN. It is 1 raffle and 2 separate winning tickets will be drawn. Both radios are Radio Shack HTX-10's which are 25 watt, 10 meter mobile rigs. The rig operates on SSB and FM but not CW as the previous version (the HTX-100) did. One is brand new in the box, only tested to check that it is receiving. The other is in very good condition (almost new).

The winning tickets will be drawn at the HPT monthly breakfast, either August 25th or September 29th. The HPT Board of Directors will decide the exact date at their next meeting in a few weeks. The date will be announced in another email. The monthly breakfast meeting is open to all. It is at 8:30 am for the August meeting and probably 8:00 am for the September meeting. The breakfast is at the Golden Corral on Mercury Blvd, next to Hampton Chevrolet.

Tickets are $5 each or 3 for $10. Tickets may be requested by email to N4STU as indicated at the bottom of the newsletter.  I will reply with your ticket numbers. Your email is your IOU. Checks may be made out to W4HPT and mailed to 115 Garrett Dr., Hampton, VA  23669. Other arrangements can be made by e-mailing me.

Good luck to all.  Stu, N4STU

SPARK members participated in Field Day with Hampton Public-Service Team (HPT) members. We had a great time and the event was very successful! The setup was on the field behind The Northampton Church of Christ on Todds Lane (Hampton). The pictures below are just a sample of those on the HPT Yahoo site (unfortunately available only to HPT members). (Note that KC4F did not reset the date on his camera.)

This information was provided to ARRL:

Bonus points claimed: Total Points Claimed:  2104
Band CW QSO Phone QSO
160 0 3
80 0 135
40 24 114
20 52 147
15 5 9
6 0 1
GOTA 0 6
Totals 81 CW 415 Phone
         

Callsigns of all operators and number of QSO's completed of the GOTA Station:
KI4TPB - 3,  KI4RWZ - 3
2 stations inside tent1 station under roofstation activitytent and GOTA

Virginia Beach Hamfest
Electronic Flea Market & ARRL Roanoke Division Convention
SEPTEMBER 15 & 16, 2007
Virginia Wesleyan College

http://www.vahamfest.com
Email: Hamfest © exis.net

Show open to the public from 9:00 A.M. till 5:00 P.M. Sat and till 3:00 P.M. Sun

For Individual tickets please contact:
Lynn Lilla, W9DJQ
848 Stacey Place
Virginia Beach, VA 23464
Email: w9djq © arrl.net
Received from Joe, K4JJS.  There is going to be a W5YI ham radio testing session in Gloucester Saturday, August 4th, at 0900 at Abingdon Vol F-R Station 3 on Rt 1216 in Hayes. 

Directions to the testing location:  The testing site is located in Gloucester County in Hayes, Va. State Route 1216. If you are coming from South of the York River, drive North on US Highway 17, and cross the York River at the Coleman Bridge. Continue North for 2.2 MILES (4th Traffic Light). Turn left on State Route 1219. There will be a Hardee's on your left at this stop light. After turning left at Hardee's drive 0.1 mile to the stop sign. Turn right at the stop sign onto State Route 1216. Then drive 0.5 mile. The testing site will be on your left, the large white building with a large parking lot. This is the Gloucester County Abingdon Fire-Rescue Squad building. Anyone coming from the North and traveling South on US Highway 17 would turn right at State Route 1219 (At Hardee's), and then follow the same directions.

The E911 address is:  2676 Hayes Road Gloucester, Va.

For a Google map of the location go to this URL:
http://www.mparc.net/index.php?page=directions (this is the same location as where the MPARC meetings are held).

For general information pertaining to the testing session please go to this URL: http://www.mparc.net/index.php?page=license-testing

TECHNICAL STUFF
Future articles wanted.

HEALTH and WELFARE

Please send me information and comments.

Humor from Jim Wise, W4PRO
Donkey Story

One day a farmer's donkey fell down into a well. The animal cried piteously for hours as the farmer tried to figure out what to do.

Finally, he decided the animal was old, and the well needed to be covered up anyway; it just wasn't worth it to retrieve the donkey.

He invited all his neighbors to come over and help him. They all grabbed a shovel and began to shovel dirt into the well. At first, the donkey realized what was happening and cried horribly.

Then, to everyone's amazement he quieted down.

A few shovel loads later, the farmer finally looked down the well. He was astonished at what he saw. With each shovel of dirt that hit his back, the donkey was doing something amazing. He would shake it off and take a step up.

As the farmer's neighbors continued to shovel dirt on top of the animal, he would shake it off and take a step up.

Pretty soon, everyone was amazed as the donkey stepped up over the edge of the well and happily trotted off!

Life is going to shovel dirt on you, all kinds of dirt. The trick to getting out of the well is to shake it off and take a step up. Each of our troubles is a stepping stone. We can get out of the deepest wells just by not stopping, never giving up! Shake it off and take a step up.

Remember the five simple rules to be happy:
Free your heart from hatred - Forgive.
Free your mind from worries - Most never happen.
Live simply and appreciate what you have.
Give more. Expect less
NOW ...........

Enough of that crap . . The donkey later came back, and bit the farmer who had tried to bury him. The gash from the bite got infected and the farmer eventually died in agony from septic shock.

MORAL FROM TODAY'S LESSON:
When you do something wrong, and try to cover your a**, it always comes back to bite you.


AREA REPEATERS, VOICE

[information from SERA Repeater Journal, except 146.940]

Please send me corrections, additions and deletions

freq
offset / tone
call sign
location
 53.250 ( – / 100.0) KT4QW Newport News
145.230 ( – / 100.0) W4MT Newport News
145.370 ( – ) W4HZL Gloucester
145.410 ( – / 127.3) KF4ADM Williamsburg
145.490 ( – / 100.0) KE4UP Hampton
146.670 ( – / 173.8) KG4NJA NASA - not back in service yet
146.730 ( – / 100.0) W4QR Hampton
146.760 ( – / 118.8) KB4ZIN Williamsburg
146.940 ( – ) ? KI4LAO ? Hampton - experimental, QRP
147.105 ( + ) KB4ZIN Williamsburg
147.165 ( + ) W4CM Newport News
147.195 ( + / 100.0) WT4RA Smithfield / Isle of Wight
147.225 ( + / 136.5) KA4VXR Hampton
147.300 ( + / 131.8) W4LG Franklin
224.540 ( – / 100.0) WB4PVT Hampton
224.620 ( – ) W4GSF Gloucester
442.900 ( + / 100.0) W4MT Newport News
444.100 ( + ) KB4ZIN Williamsburg
444.550 ( + / 167.9) W4QR Hampton
AREA NETS - not guaranteed, frequencies in MHz

Please send me corrections, additions and deletions

Sunday 9:00 p.m. - Franklin, 147.300
Monday 6:30 p.m. (first & third Mondays of month) - ODEN, 3.947
  7:15 p.m. - HPT Training, 145.490
  8:00 p.m. - York County / Poquoson, 146.670
Tuesday 8:00 p.m. - LPEN, 147.165
  8:15 p.m. - LPEN Packet, 145.730
Wednesday 7:30 p.m. - Williamsburg/James City County, 146.760
  9:00 p.m. - Coastal Linking (possibly still active), 147.300
Thursday 7:30 p.m. - D10/WTRA, 147.300
  8:00 p.m. - MPARC, 145.370
SPARK OFFICERS
Charlie Stokes, WB4PVT President
Ed Brummer, W4RTZ Executive Vice-President
vacant Vice-President
Cindi Verser, AI4OO Secretary
Jim Wright, WA4IVM Treasurer
Chris Hosman, KC4F Call Sign Trustee
John Howe, KE4UP Repeater Chairman
ABBREVIATIONS

BoD - Board of Directors
DEC – District Emergency Coordinator (ARES)
EC – Emergency Coordinator (ARES) (of a locality)
HPT - Hampton Public-Service Team
LPEN - Lower Peninsula Emergency Net
MPARC - Middle Peninsula Amateur Radio Club, (Gloucester/Mathews County)
NNACT - Newport News Amateur Communications Team
PARC - Peninsula Amateur Radio Club
PEARS - Peninsula Electronic Amateur Radio Society
SPARK - Southern Peninsula Amateur Radio Klub

NOTE: We have removed all direct email links from this newsletter in order to reduce the spam that folks have been receiving. However, you can still send email to people listed on this newsletter by clicking on their BLUE call sign. This link will take you to the www.aresva.org email processing web page. Other email references have the @ symbol replaced by with © symbol.

Ideas? Comments? Suggestions? Contributions? --- please send some email to The SPARKGAP Editor.
Stu, N4STU

Page last edited on August 1, 2007

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