February Notes from the Presidents Desk.
Strange but until Rod Mills brought his Humvee for club members to climb all over I had no idea what a Humvee looked like, in fact until a few Months ago I had not come across the word. Yet a friend has loaned me a novel to read by Robert Ludlum and there in the fast moving script the hero is faced by rows and rows of Humvee's. Thank you Rod for allowing club members to view what is I believe one of only 14 Humvee vehicles in Australia and allowing me to enhance my personal education.

Well our 2003 programme has kicked off well. The shack visit to Kathy & Phil Paveys was enjoyed by all present, many thanks to them for arranging a pleasant evening. Thanks to too Chris VK3QB for introducing us to the very

portable Buddy Pole. I am sure we are going to hear more about these antenna's. Our Australia Day weekend away to Neerim South and environs was enjoyed

by those hardy souls who braved the extreme temperatures and thick smoke.

But we were rewarded not just with good company but also with delicious foods from the various country outlets we visited and the hotel meal on the Saturday evening. Thanks to Ian & Val Benson and Ian & Dianne Jackson for organising things.

We have again been given room by the local library group to showcase Amateur Radio to the reading public. Thanks to Russ White a display cabinet has been set up in Pakenham Branch Library for this month, thereafter to move for a month at a time around the district. The display includes various pieces of radio equipment, call books, club magazines and information on GGREC and our forthcoming radio classes. We are grateful to those who have loaned the items used in the display.

Keep your eyes on the event Queue for future happenings, we have speakers arranged through until May on meeting nights. The Labour Day trip to Heyfield/Sale has been cancelled but I believe a few members will still be making their own arrangements down there for this holiday weekend. The Pub meal on the 28 or29th of March will be at Trios Grant St Cranbourne a deposit of $5 per chair refundable on the night will be expected.

The QSL cards for our VI3BJA activity have been ordered and will be available soon. We will get all the VI3 users together soon for a marathon QSL writing session.

Our speaker for February is Mr Harry Papas, a wild life officer who will talk on the use of radio tagging of birds among other things about his daily work.

Some dates of special note- Club AGM on the second Friday of April, ie 11/04/03. The Hamfest /Sale at the new and bigger site will be on Saturday July 19^th. Please start spreading this date to your AR friends.

That seems enough from me for this Month I look forward to seeing you "on air" or at the next meeting the theme of which will be, RDF or Away with the Birds.

73s to all.

Peter. VK3VB.

Link to top of Page

GGREC Event Queue

Link to top of Page


GGREC General Meeting Minutes – 17 January 2003

Date: 17/1/03 Start time: 8:50pm. Chairperson: Peter VK3VB Minute Taker: Ian VK3BUF
Present: All on the list that was passed around
Visitors and Guests: Nil Apologies: Mike KTO & Nareé, Andrew HFA, Mariana, Keith Sadler HSS, Ivan ARV, Bruno BFT
Correspondence Received: Mags from other Clubs, AMP account change
Treas Rpt: Read by: BUF, Moved: Ian BUF, Seconded by: Reg VK3UK Carried: Yes.
Prev Minutes: Circulated by: Gateway, Moved: Helmut DHI 2nd: Pat OZ
Business Arising from Previous Minutes:

• John XJW still eating the Christmas Hamper
• Booking of Cranbourne hall for Hamfest sale is confirmed.
• AOCP class – all on track
• DF Hunt 22^nd of Feb, rule changed for single vehicle teams planned.
• VI3BJA made almost 1200 contacts last year, QSL cards now to be ordered.
• An Exam is scheduled for 1/3/03 at Peters place. Applic. Cut-off is Feb22
• Thanks to Rod Mills for demonstrating his Hum Vee vehicle.

New Business:

• Library display of radio gear to go ahead this year, Russ White to organise.
• Trip to Lake Goldsmith steam rally in May considered. I5 interested people.
• Colin VK3HR said that Frankston bike track is open for a possible bike event.
• Australia Day weekend to Neerim South is prepared ok.
• Labor Day weekend in sale has been considered. Only for sites so far.
• 2003 Callbooks not yet available.
• Club trip to Flinders Ranges over 2 wks for Sept 2003 attracted good interest.
• John ZK has compiled a CD of freeware SSTV programs and digital SSTV.
• An enclosure for the Club BBW to be built, a volunteer is sought.
• AGM moved to April 11 to avoid Good Friday near Easter.
• Reg has a fish tank for sale. (the fish needed more lemon juice)
• Chris VK3QB may bring his new HF antenna to the next prac night
• Club Shack project – options discussed, more investigation to be made with council.
• Meeting closed at 9:05pm

Link to top of Page

Digital SSTV

Way back in the good old ‘60s, Copthorne McDonald stunned the amateur radio world with his

FAX-like SSTV, a convenient means to transmit pictures to any amateur radio station anywhere in the world. This system featured WWII radar tubes with "long persistence" phosphors. However, these soon dried up and SSTV systems had to use "fast-to-slow-scan converters" for SSTV transmission and reception (manufactured by the likes of Robot Research Inc.).

Today, amateurs have been sending pictures with very high resolution and colour, using computer packages, such as JV Comm 32, Chroma Pix and Mscan. But if you have just upgraded your favourite SSTV package, consider the fact that, very soon, it will be a good candidate for Pharaoh’s tomb, being an analog system, BECAUSE SSTV HAS JUST GONE DIGITAL!

After you have donated your analog SSTV "dinosaur" to a museum of your choice, obtain the "DigSSTV" digital SSTV package. Such comes in two varieties: one for Windows 98/Me and the other for Windows XP. Contact either Erik, VK4AES or Chris, VK3DNH. I have also circulated a CD-ROM which I have compiled, which contains DigSSTV.

So, who is responsible for this new SSTV marvel? Early SSTV pioneer Don, W9NTP had the first version of this method of error-free file transfer, and Barry, KB9VAK, is the author and "guru" of this new SSTV system. Under the GNU agreements, this package is an absolute "freebee."

Unlike analog SSTV, you will not be able to view the picture as it is being transmitted. You will have to wait for about 20 seconds to about 8 minutes for the picture to be transmitted, plus extra time for the received audio to be conditioned and converted before the picture appears on the screen. When sending an image, you must first convert the image to a ".WAV"-file (in the program package itself) and then transmit the image after such has been generated. The two photos, above, are an example of the high quality that can be expected, even on a band, such as 80 Mx. However, it is still possible, at times for the file to become corrupted, either during transmission or at the receiving end.

Also, you are not confined to a 320 x 256 picture, as per analog SSTV. Any screen size and aspect ratio can be transmitted. And it is not limited to just SSTV pictures. You may transmit any PC file, provided the transmission time does not exceed ten minutes. It is even possible to transmit a twelve-second,

full-motion video clip, provided that it does not exceed twelve seconds duration, and it is rendered into a low-resolution, ".WMV"-file, with 8 KHz-sampled, 8-bit audio (file size (approx.) 42 k-bytes). The receiving station can then use Windows Media Player to view your transmitted ".WMV"-file.

HOW DIGITAL SSTV OPERATES
When a picture is loaded, it is converted to a jpg file of the chosen compression. High compression gives a poor picture, but a small file which may be preferred on a slow computer. This file is then automatically converted to a special ".WAV" file ready for transmission. The wait for this to complete depends on the file size and computer.

Pressing the TX button will send this file via the soundcard with PTT if selected. To RX, pressing the RX button will begin file capture. This must be started before the picture tones begin. Do it when the first two tone signal is heard. Press again when the tones are finished. The captured audio is then placed into a buffer and converted into a ".WAV" file. This wav file must then be converted to a samplerate of 11025 and 16bits per sample to be accepted by the decoder. Your particular sound card settings do not matter.

The ".WAV" file consists of three main segments, the leader, main body and trailer. The conditioned ".WAV" file is then sent to the decoder and there will again be a wait till decoding is finished and a perfect picture or error message will appear. In very simple terms, The decoder uses information in the leader to compensate for some mistuning. It also senses and corrects timing differences the sender's sound card and the receiver's sound card. The main body contains the file data and the trailer signals the end of file.

It is most important to have RX and TX linearity. Use the "Send Tuning tones" to initially let the RX station tune to frequency and to check your transmitter linearity. The two tone signal has three audio amplitude steps. Each step should reflect a 3db change in TX output. Compression and alc are to be avoided. On RX, line up the 2 tone spikes with the two white lines. The RX must also have a linear response. Avoid clipping (audio overload or high noise blanker settings.) Noise blanker clipping is generally OK if the clipping threshold is higher than the peak data, sub-carrier level. FM, particularly, must be adjusted correctly

If the SSB voice sounds OK, the freq will be good enough but the scope can be used to fine tune. The freq can be a bit off but: DO NOT CHANGE THE TUNING AFTER CAPTURE BEGINS! Even a few cycles may fail the decoding. Thus the TX must also have good stability (most do). Also, let tasks complete before starting the next. eg: Don't try to make a ".WAV" file, TX or RX at the same time or there may be unexpected results. Avoid frantic button pushing. If the program is crashed, then remove all traces with the "ctrl-alt-del" (the "Vulcan Neck Pinch") method. There may be two instances running.

Reduce CPU loading, if possible, such as background processes. A CPU at 2GHZ is great, but the program will work with slower computers but the decoding especially will be slower. Turn the scope OFF when not being used. Always leave it OFF with slow computers. In "setup" use "Low Quality" to start with till you become used to the program. Use 20 redundancy also.

CONCLUSION

It is all part and parcel of the digital revolution! Like Copthorne McDonald’s original monochrome SSTV system, today’s analog SSTV packages will shortly become candidates for a museum. It is free, it works and you will be keeping up with the "Joneses" by having the latest digital SSTV system. And by using the ".WMV" video file system, one day, you could transmit on 20 Mx a 12-second video clip, with audio, of yourself, your family and your station.

Link to top of Page

Open up TV waves to wireless
By Richard Shim
Staff Writer, CNET News.com
January 16, 2003, 2:51 PM PT

The Federal Communications Commission is quietly considering opening the television broadcast spectrum for use by other wireless devices, including Wi-Fi products.

The proposal, revealed in a notice of inquiry adopted last month, would allow devices using unlicensed spectrum--bandwidth not licensed to broadcasters--to operate in the TV broadcast spectrum. However, they would tap into only those parts of the TV spectrum not being used and only be allowed to do this when they wouldn't interfere with authorized services.

The Dec. 20 notice will take effect when it is published later this month in the Federal Register, said an FCC representative. At that point, the agency will kick off a 75-day comment period.

The regulatory body is expecting a dogfight from TV broadcasters who in the past have been very protective of their territory--opposition that could derail the proposed changes or delay them.

"We're in for a bit of a bumpy ride," said Alan Scrime, chief of the policy and rules division in the FCC's office of engineering and technology. "TV broadcasters are an influential bunch. We're not expecting this to be a real quick one."

The FCC has been pushing TV broadcasters toward digital television, in order to free up the analog TV spectrum for uses such as wireless home networking technology.

The agency is looking at TV spectrum because it provides significant amounts of bandwidth per channel. In addition, the frequencies and amount of unused TV spectrum varies in different regions, leaving more opportunities for use, according to the notice.

Current 802.11b-based, or Wi-Fi, wireless home networking products operate in the 2.4GHz band and can interfere with other devices--such as cordless phones--in the same band. Expanding the spectrum of unlicensed devices would mitigate many interference issues, and could pave the way for new types of devices that can operate in other bands.

Scrime said that manufacturers have been developing products that can sense when they would interfere with other devices.

The FCC and specifically its chairman, Michael Powell, have promoted the adoption of broadband access by consumers. Wireless home networking technology has been viewed by the regulatory body as a significant complement to broadband, because it makes the service more valuable by allowing multiple consumers to share access wirelessly.

Others in Washington have been promoting the use of Wi-Fi technology. Late Tuesday, Sens. Barbara Boxer, D-Calif., and George Allen, R-Va. proposed the Jumpstart Broadband Act, which would allocate additional radio spectrum for unlicensed use by wireless broadband devices and add wireless technology as a third method of improving the establishment of broadband access.

The notice of inquiry to be published does not specifically identify Wi-Fi wireless home networking technology. However, as technology that uses unlicensed spectrum, Wi-Fi products would get a boost.

Wi-Fi products operate in the 2.4GHz and 5GHz bands, which are unlicensed parts of the radio spectrum. Analog TV stations operate in 6MHz channels and the FCC is targeting the 54MHz to 72MHz, 76MHz to 88MHz, 174MHz to 216MHz and 470MHz to 806MHz bands.

"Wi-Fi should benefit, if this comes to pass," Scrime said.

The point of the notice and similar efforts by the FCC are to make more efficient use of the radio spectrum, as wireless devices become more popular among manufacturers and consumers.

"The FCC wants to encourage the sharing of spectrum and take advantage of it when it's not being used, as long as there is not interference," Scrime said. "Long term, we want to make sure there is enough of it available so that it isn't crowded to the point where it doesn't work."

Link to top of Page

Australia Day Weekend 2003
By Dianne Jackson VK3NDI
The Neerim South Caravan Park was the perfect venue for the GGREC Australia day Weekend. We had a large camping area reserved for us, with plenty of shady spots for caravans, tents and social gatherings. There was also a covered barbecue area. Both Helmut and Peter Pavey set up extensive antennas in the park.

Saturday
A group of 28 people were in attendance at our rendezvous at the Robin Hood Hotel. The Drouin West Berry farm was our first stop for the day, where the strawberry icecream and milkshakes were very tasty and nice and cold. I bought some Raspberries that melted in the mouth, unfortunately most of them ended up in Ross’ mouth instead.

On to the Jindivick Smoke House, where we sampled many different kinds of smoked meats. Some said that the smoked eel was very nice although I wasn’t game enough to try it for myself.

The Piano Hill Cheese Factory was next on the agenda, they had very good air conditioning, and, some excellent tasty cheese.

At the Wooden Goose we stopped to have a look at some weird and wonderful antiques. The proprietor there Garry Miles gave us a dozen free range eggs to take with us. After the antiques dealer visit, it was on to Rokeby for a picnic lunch.

The 44º heat was making itself felt by this stage, so we went our own separate ways, to try and keep cool. A cold shower and a nap in front of the air conditioner, did it for me until the power in the area failed. Some went to the local Swimming Pool, while others headed straight to the pub. (for the air conditioning of course.)

Dinner at the Kings Arms Hotel, in Neerim South was very pleasant, the meals were huge and the desserts were delicious. We watched a spectacular sunset from the Hotel balcony before we left. Back at camp as we were talking, Bruno spotted the space station orbiting overhead. Peter VK3KCG had some problems with the battery running his fridge and had to re-direct power from the spare battery in our van.

Sunday
At 4:00am a hot north wind woke up many of the campers as it roared in at 32º and stayed there until a cool change came at 7:30am. Warragul was our first stop, where we watched the Australia Day Parade, featuring Ian and Val Benson in their old Buick. After the flag raising we went back to camp for some lunch.

A few of us drove out to Noojee after lunch and inspected the old trestle bridge. Then we drove out to see the 270 year old ‘Ada’ Tree. It was a lovely walk through the rain forest, to the ‘Ada’ Tree, which was a very impressive 65 metres in size. Extensive new board walks made the going much easier on the way back. During our evening barbecue dinner at the caravan park, we were cooled down by a good shower of rain that lasted most of the evening. We congregated in the covered barbecue shelter and indulged in coffee and conversation well into the night.

Monday
Packed up the camper and drove home. Some of the others stayed longer, but I think, despite the heat, we all had a great weekend.

Link to top of Page


Highlights from the Australia Day camping weekend.
Can you answer this quiz?

Link to top of Page


High Mobility Multipurpose Wheeled Vehicle (HMMWV)

Paul VK3TGX

The High Mobility Multi-purpose Wheeled Vehicle (HMMWV) is the replacement vehicle for the M151 series jeeps. The HMMWV's mission is to provide a light tactical vehicle for command and control, special purpose shelter carriers, and special purpose weapons platforms throughout all areas of the modern battlefield. It is supported using the current logistics and maintenance structure established for Army wheeled vehicles. The HMMWV is equipped with a high performance diesel engine, automatic transmission and four wheel drive that is air transportable and droppable from a variety of aircraft. The HMMWV can be equipped with a self-recovery winch capable of up to 6000 pound 1:1 ratio line pull capacity and can support payloads from 2,500 - 4,400 pounds depending on the model. The HMMWV is produced in several configurations to support weapons systems; command and control systems; field ambulances; and ammunition, troop and general cargo transport.

LTV HMMWV M998-series multipurpose wheeled vehicle variants include:

• M998 cargo/troop carrier without winch
• M1038 cargo/troop carrier with winch
• M966 TOW missile carrier, basic armour, without winch
• M1036 TOW missile carrier, basic armour, with winch
• M1045 TOW missile carrier, supplemental armour, without winch
• M1046 TOW missile carrier, supplemental armour, with winch
• M1025 armament carrier, basic armour, without winch
• M1026 armament carrier, basic armour, with winch
• M1043 armament carrier, supplemental armour, without winch
• M1044 armament carrier, supplemental armour, with winch
• M996 mini-ambulance, 2-litter, basic armour
• M997 maxi-ambulance, 4-litter, basic armour
• M1035 soft-top ambulance, 2-litter
• M1037 S-250 shelter carrier, without winch
• M1042 S-250 shelter carrier, with winch
• M1069 tractor for M119 105-mm light gun

Primary function: The HMMWV provides a variety of wheeled vehicle platforms. These are cargo/troop carrier, armament carrier, TOW missile system carrier, shelter carrier and two ambulance variants (2- and 4-litter). The HMMWV will also be the prime mover for the AN/TRC-170 Radio Digital Terminal and the Pedestal Mounted Stinger System.

Length: 15 feet (4.57 meters)
Width: 7.08 feet (2.16 meters)
Weight: 5,200 pounds (2359 kilograms)
Height: 6.00 feet (1.83 meters) reducible to 4.5 feet (1.37 meters)
Engine: V8, 6.2 litre displacement, fuel injected diesel, liquid cooled, compression ignition
Horsepower: 150 at 3,600 RPM
Transmission: 3 speed, automatic
Transfer case: 2 speed, locking, chain driven
Electrical system: 24 volt, negative ground, 60 amps (Generator, not alternator) optional 250 amp generator

Brakes: Hydraulic, 4-wheeled disc
Fording depth:
without preparation: 76 centimetres (2.5 feet)
with deep water fording kit: 1.5 meters (5 feet)
Fuel type: Diesel
Fuel capacity: 94 litres (25 gallons)
Range: 563 kilometres (350 miles) highway
Unit Replacement Cost: $50,000 (US? in 2000)

Text from "www.fas.org" web site - just search for "HWWMV" for further information

Searching for "HUMV", "HUMMER", etc will lead you to the non-military version.

Link to top of Page

GGREC IRLP/70cm Repeater Project
The GGREC 70cm REPEATER VK3RLP is on the air! Frequencies are 434.475MHz input 439.475MHz output. The repeater is operating from my QTH as we are still working on the cabinet for its final location. Connection to the IRLP can only be accomplished using the VK3RLP repeater.

Unable to get a front end filter on the correct band for the repeater. I decided to modify the filter already in the repeater. After rewinding 8 helical filters and some mods to the local oscillator tripler, I achieved 0.2uV at 10dB sinad which is very good for this type of receiver.

The transmitter in its present form, would only produce about 16W, which is far below its 50W capability. By adding some capacitors in the power amp, I was able to get about 48W which I think is about its limit.

The controller was constructed using a PIC12C671 microprocessor and a CTCSS module for the muting of the CW identify for IRLP. The microprocessor controls the PTT timeout, the CW identify timing, generation of the CW tones and CTCSS control.

Using one antenna for both TX and RX on a repeater requires a Diplexer which can reduce transmit power some 25 to 50% and receive sensitivity 2 to 3 dB. A split antenna system , that is one antenna for TX and one for RX removes the diplexer so that full TX power and receive sensitivity is achieved. With a split antenna system some 25 to 50 ft of separation between antenna’s is required to stop receiver overload from the transmitter. At my QTH I am using a split antenna system for the repeater, with about 30ft between antenna’s. Slight receiver overload is present, but if I use one of the cavity filters from the Diplexer (6 of them are used in the diplexer) in the receive antenna line, the overload problem is removed. This will only reduce the receiver sensitivity by 0.5dB. At the repeaters final location this will all change as antenna separation and different antenna’s will be used.

I have made up a front label, for the transmitter and receiver and it is temperately installed into a small rack under my work bench until its cabinet is finished and installed.

73s John VK3XJW

Link to top of Page

GGREC Fox Hunt 2003 (Sat 22^nd FEB)
I would like to have everyone meet at the Indoor Sports Complex --- Henry St Pakenham. Melways reference is Map 317 D7. The time to meet is 9am. Lunch will be in a park somewhere and a BBQ will be provided. Please bring ALL your own food etc.
We will be attempting a new format for the hunt where each car is an individual hunter which gives potential for a better hunt. (Well I hope so anyway)

Each team will need the following:
A car (hopefully in good working order.)
A pencil or 2 (in case one gets busted)
A flat surface to lay the maps on to better gauge the direction of the fox. (namely me)
A compass is a definite advantage.....
and so is a ruler.
AND if you dont have a 2mtr rig capable of operating on 146.225 at least, plus a DF antenna, then you just dont fit the criterion for this event.
All your own food and drinks.

Albert Hubbard
VK3BQO (Alias "The Fox")