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VE3ERC-LUB

MARCH 2013 

Volume 3 Issue 3 

IN THIS ISSUE 

DX PROPAGATION PRIMER P.2

SDR DONGLE BASED RADIO P.4

WED. NITE NET P.5

RFM22 RADIO P.6

MARCH MINUTES P.7

 

President: Al, VE3TET

Vice-President: Johan, VA3JBO

Secretary: Bob, VE3IXX

Treasurer: Reg, VE3RVH

Trustee: open

QSL Manager and Lighthouse: Bill, VE3WBJ

Repeater manager and maintenance person: Carl, VE3FEF

Website Admin: Johan, VA3JBO

VE3QB, Bruce’s antenna system. The white shed just behind the evergreen tree is his dedicated “ham shack”.

Now that many more amateurs can now use the HF bands, I thought it might be useful to explain the most basic elements of DX propagation.

The sun emits electromag-netic radiation and matter as part of the nuclear fusion process. Electromagnetic radiation in the ultraviolet region ionizes the F region, radiation in the soft x-ray area ionizes the E region, and radiation of the hard x-rays ionizes the D region.

The F region (made up of F1 and F2) is the prime region for ham radio DX operation.

SUNSPOTS (not to be confused with Solar

Flares) are areas on the sun emitting ultraviolet radiation. Thus they are tied to the ioniza-tion of the F region. The spot in the centre of the picture would swallow the earth. The Smoothed Sunspot Number (SSN) is calculated using six months of data before and after the desired month, plus the data for the desired month. Because of this amount of smoothing, the official SSN is one-half year behind the cur-rent month. Unfortunately this amount of smoothing often masks any short-term unusu-al solar activity that may enhance propagation, and so the eSSN (effective SSN) is more useful on a daily basis.

A DX PROPAGATION PRIMER

Or HOW YOUR SIGNAL GETS FROM

YOU TO ANOTHER HAM

Part 1 Compiled by

Bill Graham VE3ETK

SOLAR FLARES are guided into the ionosphere along magnetic field lines and thus can only impact high lati-tudes where the magnetic field lines go into the earth. Solar matter (which includes charged particles—electrons and protons) is ejected from the sun on a regular basis, and this comprises the solar wind. On a “quiet” solar day the speed of this solar wind heading toward earth aver-ages about 400 km per sec-ond and so there is a delay between the happening and the effect. The sun’s solar wind significantly impacts

Earth’s magnetic field. Instead of being a simple bar magnet, Earth’s magnetic field is compressed by the solar wind on the side facing the sun and is stretched out on the side away from the sun (the magnetotail, which ex-tends tens of earth radii downwind). The sun’s electromagnetic radiation can impact the entire ionosphere that is in daylight.

There are two measurements of this effect: the daily A index and the three hour K in-dex. The A index is an average of the eight three hour K indices, uses a linear scale and goes from 0 (quiet) to 400 (severe storm). The K index uses a quasi-logarithmic scale and goes from 0 to 9 (with 0 being quiet and 9 being severe storm). Generally an A index at or below 15 or a K index at or below 3 is best for propagation.

SDR Dongle-based Radio by Terry VE3XTM 

At our February meeting I gave a talk as well as a demonstration of “dongle” based Software Defined Radio (SDR). These dongles are devices that plug into your computer’s USB port. They were originally designed for DVB-T which is for receiving European digital television. The dongles do not work for North American TV as we use a different digital standard here.

However, SDR for these dongles began when DVB kernel developer Antti Palosaa revealed that an ecnomical USB EzTV 668 DVB -T/FM/DAB USB dongle based on the RealTech RTL2832U chip, could be used to stream raw I/Q samples to most PC’s. Since that time enterprising amateurs and software developers have written several programs to present this digital data in a very versatile open source software defined radios that are available for a free download on the Internet.

A recent article in QST titled, Cheap and Easy SDR, by Robert Nickels, W9RAN, outlined how to get SDR up and operating on your PC.

http://www.davegardner.org/Ham/PDF/EasySDR.pdf

Basic USB dongles such as the Terratec dongle are capable of receiving radio frequencies from about 54MHz up to about 2GHz. There are some that are capable of going lower in frequency down to 24MHz. The dongles will receive all modes, AM, FM, FM stereo, USB, LSB, DSB and CW. These dongles cost about $20 and with the proper antenna one can listen in on the VHF, UHF and microwave portions of the band, including stereo broadcast FM .

The article by Nickles outlines how to download and install the software using a simple batch file install procedure. The soft-ware version that most are using is the SDRSharp or SDR#.

SDR# screen shot showing the panadapter and waterfall screen Source http://sdrsharp.com/ 

The software allows the setup and frequency correction calibration of the radio, as well as adjustments to sampling rates, sen-sitivity and a range of other features, including the storage of favourite frequencies and a recording/playback of band activity, all in the VHF and UHF bands.

But all is not lost for those who prefer to work in the HF bands. Recent development have seen the design and availability of reasonably price up-converters that allow the use of the dongle in our favourite amateur bands. The up-converter boards are available for about $50. A few SMA adaptor cables are all that is needed to complete a basic SDR radio that will cover the range from the AM broadcast band up to the lower part of the microwave spectrum. For a review of the various up-converters available see the link below.

While we cannot expect these dongles to rival commercial radios at this time, they do give amateurs an introduction to SDR and the ability, with the panadapter, to see the signals on the various bands. We are only at the beginning of this new radio technology and the future will hold many more developments through the creative use of software and digital processing of signals.

WEDNESDAY NITE NET CONTROLLERS

APRIL 3 – DOUG VE3CXU

APRIL 10 – CARL VE3FEF

APRIL 17 – BILL VE3ETK

APRIL 24 – M E E T I N G

 

MAY 1 – AL VA3TET

MAY 8 – RALPH VE3EUC

MAY 15 – HARRY VE3EIX

MAY 22 – M E E T I N G

MAY 29 – WALLY VE3LCR

 

THE RFM22 RADIO PROJECT

BY JAMES LITWILLER VE3JLC 

The RFM22 is a low-cost ISM (Industrial, Scientific & Medical) FSK (Frequency Shift Keying) transceiver module which offers communication at tuneable frequencies in the 70cm band. It has an adjustable output power of up to +17 dBm. The wide operating voltage of 1.8-3.6 volts, plus a low current consumption makes the RFM22 an ideal little project.

This is the 3rd or 5th iteration of my RFM22 FSK radio project proto-type. These are won-derful little radios that can have you dreaming about the wildest software projects. Also the choice of the Arduino Pro mini 3 volt prototype board makes many things quickly possible and can easily enough run two radios at the same time.

I’m not sure yet how this is going to come together, as just a fox hunt radio that makes a little puff sound on the amateur radio 70cm band or other more advanced possibilities. To-day, I thought it might be interesting to try to construct a compact antenna to accompany the radio. Previously, a 1/4 wave length wire was used, which was fine, but opportunities exist for many possibilities.

Two 40mAh lithium batteries are intended to power this project. Connecting them in parallel could have complications, but I don’t think it will cause a power outage (Hi Hi) and some tests have shown that with precautions it can be done safely. Software projects will need to attempt power considerations. The container for an SD memory card (as shown in the photo) works as a god case for the project.

Further information can be found at:

Www.sparkfun.com/products/9821

http://arduino.cc/en/

http://playground.arduino.cc/

 

MINUTES FOR THE MARCH MEETING

 

WILF VE3HYV

ROB VA3AHP

JIM VE3JLC

REG VE3RVH

GREG VA3GSM

BRUCE VE3QB

JOHAN VA3JBO

PAUL VE3PVB

TERRY VE3XTM

JIM VE3JMU

CARL VE3FEF

RALPH VE3EUC

AL VA3TET

GORD VE3EOS

RICH VE3DCC

DOUG VE3CXU

HARRY VE3EIX

BOB VE3IXX

 

The meeting was begun with each member introducing their name and call sign. Gord VE3EOS, who was visiting, was warmly welcomed.

The first order of business was the Treasurer’s Report. Reg VE3RVH handed out his annual statement and reminded everyone that the membership fees are due. The ERC has $2,551.68 in the bank. Reg made a motion to accept the minutes and it was se-conded by Bruce VE3QB.

The second item on the agenda was that Al needed some-one to help assess the equipment from the estate of Bing Harris. Ralph (VE3EUC) volunteered to go with him. There will also be a need for volunteers to dismantle Bing’s tower and 4-element beam. Johan VA3JBO, Jim VE3JMU and Terry VE3XTM will set a date with Al to get the job done.

For new business, Bruce VE3QB explained some of the diffi-culties he encountered to re-configure the IRLP on his computer when he changed servers. It took several phone calls to Dave Cameron before he finally got it up and running well again. Our thanks to Bruce for his hard work. Bruce suggested that the club make a cash donation to the IRLP service and made a motion to send them $50.00. This was seconded by Ralph VE3EUC.

Reg VE3RVH giving the Treasurer’s Report.

Al spoke about the fleamarket on June 2 and about the need for more volunteers to run the Ontars net. He said that we will need about five people to cover the hours. Paul VE3PVB, Bob VE3IXX offered to help Al. Rich VE3DCC and Harry VE3EIX may possibly be able to help as well.

Al reminded all members to mark their calendar for the Field Day (June 22 and 23) at Bob’s (VE3IXX) farm. Al moved that the Sunday meal again be the traditional steak or roast beef dinner. This was seconded by Johan VA3JBO.

The final item of business was a discussion of the Lighthouse weekend (in Au-gust) at Point Clarke. Given the difficulties with a decent antenna last year and the fact that the lighthouse was still under re-construction, Al wondered whether it was even worthwhile to participate this coming August. He suggested that if the lighthouse is still not useable this summer, we may just forget this project.

Having finished the business part of the meeting, Al began a discussion of the up and coming ERC projects for this year. The first idea was for an HF pre-selector using a Cascode amplifier. Using schematic diagrams on the board, Al explained how this am-plifier works.

The second project idea was an EH antenna using a cone shape. While the flute shaped EH antenna (which Al and Paul had built a prototype) was more desirable, the cone shape is much simpler to build and works well. The EH antenna is only about three percent of a wavelength (great for smaller spaces), has a low noise level and works like an isotropic antenna.

EDITOR’S NOTE:

A special Note of thanks to Bruce VE3QB for his many frustrating hours of work trying to get his computer to run the IRLP for the ERC repeater.

We can all appreciate how difficult computers can be at times. Having the IRLP available to all who use our repeater is a great asset.

 

VE3ERC-LUB

FEBRUARY 2013 

Volume 3 Issue 2 

 

IN THIS ISSUE 

40M MAGNETIC LOOP ANTENNA P. 2

EASY & CHEAP CW KEY P. 7

WEDNESDAY NITE CONTROLLERS P. 8

MINUTES FOR THE ERC FEBRUARY MEETING P. 8

 

President: Al, VE3TET Vice-President: Johan, VA3JBO

Secretary: Bob, VE3IXX

Treasurer: Reg, VE3RVH

Trustee: open

QSL Manager and Lighthouse: Bill, VE3WBJ

Repeater manager and maintenance person: Carl, VE3FEF

Website Admin: Johan, VA3JBO

 

It’s no wonder that Ken VE3KCY puts out such a power-ful signal from his high elevation vil-lage of Alma. Take particular note of his EH antenna on the top of the long tower. Thanks Ken for the photos.

 

VE3ERC-LUB

 

Volume 3 Issue 2

 

Page 2

 

A 40M MAGNETIC LOOP (IN THE GARAGE ATTIC) 

By Bill Graham VE3ETK

A fter I had my stroke it was clear that my wife and I needed to move to a one floor house. The result was the lovely present QTH, but it came with antenna restrictions. Already interested in magnetic loops I bought an MFJ-1786 for 20-15-10M (with magnificent results – not a 5 element beam at 100’ – but great just the same) and built a 40M loop, which is what this article is about. First contact Cuba, second Germany, and after a while Turkey, so I’m happy with this one too.

I must give credit to K8CIT as that’s where I got my starting point – from his design as found on W2BRI’s web site. The concept is to fold the loop so it takes less space and will still give a decent Q

It is all made from .” copper pipe (inexpensive red grade) with every elbow and connection soldered. The electrical resistance of the antenna MUST be low (we’re talking fractions of an ohm) to get a good Q and a tiny bit of oxidation will make the resistance rise very quickly! The uprights are 60” long, as is the long bottom section. The top sections are 28” long each, and the bottom short sections are 27” long, although I trimmed one of them shorter to make the shortest possible connection to the tuning capacitors. I think Fig. 2 shows some of this more clearly, as well as the support base and some of the insulators I made using PVC plumbing ‘Ts’. They had a short PVC pipe section inserted and hot glued into a matching hole in the base. Hot glue also provided the adhesion needed to keep the pipe in place. Solder the elbows on first!

 

 Fig. 1 shows both the structure of the loop and the resulting pattern when the bottom of the antenna is 10’ high (garage attic).

 

The points x/x are where the tuning ca-pacitor system connects (more on that later). The purple dot on the structure is the Gamma feed point (more later also).

 

Here you can clearly see the placement of the motorized tuning capacitor (some serious upgrades have been done here, which I will describe and show shortly) as well as some details of the Gamma match.

I had some great help getting the antenna in place from my good friend Rick Harrison (who also took the pictures) and Al Macdonald VA3TET (who has done my upgrades) – they will attest to the soldering.

Fig. 3 is looking up at the antenna top joints. The insulator/support is a nylon cutting board from the dollar store. You can also see how it is OK to fit the antenna around the roof struts.

In my original design I built a motor driven capacitor with glass insulation and copper plates in a wooden frame as seen in Fig. 2. It worked wonderfully, but after a couple of years it didn’t stand up to the cold and dampness.

 

VE3ERC-LUB

 

Volume 3 Issue 2

 

Page 3

 

I had also used some little R/G8 coax stubs as added capacitance. Let me caution you against using this ap-proach across a loop. It was found that putting 80 Watts or more into the loop then heats the coax capacitors that are in parallel with the loop, causing them to change capacitance and detune the loop. These were re-placed with a variable capacitor (about 15pf mid position that was still needed in the latest update) that reso-nates the loop to 40M. This capacitor has wide spaced plates to handle the voltage. A lot of “On Air” time has proven this approach is stable and reliable.

Fig. 4 shows the latest motorized tuning system. The motor driven capacitor was modified into a split stator capacitor so that there are no moving contacts to cause resistance that would lower the Q. The other ‘little’ capacitors were made from the leftovers from the conversion and limit the range of the main capacitor’s tun-ing, something you don’t need to do if you are happy with the motor’s speed and your needs.

Let’s get a better look at the Gamma matching.

I used the shield of RG8 coax to form the Gamma ‘rod’ and held it away from the antenna leg with ceramic insulators, not because the insulation was needed but because the length and mounting was right and simple.

 

Page 4

 

I used the shield of RG8 coax to form the Gamma ‘rod’ and held it away from the antenna leg with ceramic insu-lators, not because the insulation was needed but because the length and mounting was right and simple.

Fig. 6 shows the antenna feedpoint coax, the Gamma match capacitor and it’s connection to the Gamma ‘rod’ (RG8 coax) by the white wire.

Fig. 7 shows the front of the control panel: Placement of the parts behind the panel is not critical, and this diagram should explain the rest:

 

Page 5

 

THE GAMMA MATCH: In K8CIT’s design he fed the loop via a ceramic toroid. That intrigued me as I like working with toroids. However, the early stages of testing showed that, while broadband (K8CIT wanted to work both 80M and 40M with one antenna), the effi-ciency was poor. I tried a Gamma Match and improved efficiency about 20 fold. The computer software RF Tools has a section to make Gamma Match calculations. As my Gamma Rod would have to bend up one side of the loop I choose to use RG 8 coax with the outside braid as the conductor. Fig. 8 shows my calculations.

CONCLUSION: This was an inexpensive and rewarding project to build, and the “On Air” results have been equally rewarding, and I had a lovely chat with K8CIT, loop to loop, one evening. Tuning the antenna while operating is very simple, and it has opened up the 40M band for me from this QTH. I encourage anyone who would like to work 40M and has limited antenna space to build one.

A capacitor from my junk box com-pleted the Match. Although it has only 1/8” plate spacing this is a low impedance point, and hence a low voltage point. As I said, the ‘rod’ needed to bend up one of the verti-cal elements, and a point was found, and soldered, that produced 1:1.1 SWR at 7.2 MHz.. Fig. 2 shows the ‘rod’ held off the vertical element with ceramic insulators.

 

Page 6

 

Page 7

 

BUILD AN EASY AND CHEAP KEY FOR CW 

A few years ago, I built myself a simple code oscillator to practice cw (I needed the practice then and still do!). It consisted of two items; a nine volt battery and a high pitched buzzer. But what I needed was a decent key. Rather than go out and purchase a commercial key, I saw an article in a magazine to build this simple, but rather attractive key- one that you’d be proud to show off. Unfortunately, I can no longer remember what radio magazine, or the author, so I cannot give proper credit. However, by show-ing the pictures of the finished prod-uct, you can see how easily it can be put together. All that is needed is a flat piece of wood, a tee hinge, a knob for a cabinet door, a small spring from an old ball point pen, two short pieces of wire and a few machine screws with accompanying nuts.

Bob VE3IXX

 

A

 

B

 

C 

 

B

 

C

 

Figure 1

 

Figure 3

 

Figure 2

 

Figure 2 shows the side view. The ma-chine screw at A comes up from the bottom of the board at B. Slip on the spring from the ball point pen, then push the screw through the “V” part of the hinge. The nut at the top at A is used to adjust the gap at C.

Figure 3 shows the bottom side of the key. The wire is attached from C to one of the connectors at the front. I grooved out the wood along the wire so the board will lie flat. The two connectors on the front each have two nuts.

 

Page 8

 

WEDNESDAY NITE CONTROLLERS 

MARCH 6 – HARRY VE3EIX 

MARCH 13 – WALLY VE3LCR 

MARCH 20 – REG VE3RVH 

MARCH 27 – M E E T I N G 

APRIL 3 – DOUG VE3CXU 

APRIL 10 – CARL VE3FEF 

APRIL 17 – BILL VE3ETK 

APRIL 24 – M E E T I N G 

 

ERC Meeting February 27, 2013 

Members present

Terry

Al

Bruce

Andy

Johan

Reg

Bob

Gord

Dennis

Jim

Jim

Carl

Wilfred

Doug

Ken

Harry

Rich

Terry took a few minutes before the meeting to set up his display of the computer, a projector and the Don-gle.

The formal meeting then started at 19:37. There is a need for help to take care of Bing Harris’ estate. A volunteer will be required to take stock of Bing’s equipment.. Johan, Jim, Reg and Dennis volunteered for the market.

Reg gave his financial statement. There is $2401.68 in the kitty.

Bruce seconded to accept the report.

All approved

 

Al gave an update on a project for the software defined radio by Terry. (60 MHz to 2 MHz, no HF band.)

For the HF band for the Dongle, a 2 MHz to 102 MHz up converter is required. (Basically it is a Oscillator and a Mixer). 50 Ohms in and 50 Ohms out. The basic version should be $15 or thereabouts, the full blown version will be close to $30.

There will be further technical discussion on this project by Al.

Terry gave his presentation on

SDR or software defined radio. Will need to ask Terry if the presentation can be made available for the meet-ing report.

The software is freeware and the dongle is $16 and of course there will be several upgrades possible.

Al adjourned the meeting at 21:10.

Johan

 

Page 9

 

A special note of thanks to Johan, VA3JBO for taking the minutes in my absence.

Bob VE3IXX

 

DO YOU HAVE A STORY, 

A PICTURE, 

AN ARTICLE ABOUT SOMETHING YOU’VE BUILT 

OR WANT TO BUILD??? 

SEND IT TO 

robertkoechl@yahoo.ca 

Or 

ve3ixx@rac.ca 

THERE IS A WIDE AUDIENCE WAITING FOR YOU! 

Bob VE3IXX

Another successful evening. Al discussed several items and most of the time was spent on the EH Antenna and its various shapes and forms.

Bob will present us with a proper meeting report as soon as his computer has been repaired. Unfortunately his equipment suffered major failure and needs to be hospitalized.