Devoted to Radio Experimentation Since 1995
Devoted to Radio Experimentation Since 1995
We are a group of amateur and professional radio experimenters who get together informally for coffee once a month to plan projects and experiments on the ham band and on other radio service bands. The club is not limited to amateur radio. Meetings are held at 204- 2526 Government Street or at a coffee shop or restaurant at 7:30 PM on the first Thursday of each month. Call 384-8392 for details if you are interested in attending.Club Projects are intended ...
1/ To provide useful radio resources in the community.
2/ To supply phone patches and IRLP nodes to visiting hams.
3/ To encourage and give classes in homebrew radio projects.
4/ To encourage experimental activity in other radio fields besides Amateur radio including CB and FRS bands. Computer to radio interfaces are a specialty of the club.
5/ For the development of commercial products through the assistance of amateur experimentation.
6/ To promote friendly co-operation among radio enthusiasts of all types.Club Organization and Policy
We are totally unstructured as a club and are neither registered as a corporation nor do we have a bank account. In reality we are just a bunch of hams who meet for coffee at restaurants to plan projects. All radio systems are built by club members and funded by the builders themselves. The club offers technical help but the operation of each system is under the control of the owner who funded it. We place no control over our membership's experimentation. Maintaining the "freedom to play" is sometimes hard work in the Victoria radio community. All of our systems are open to the community to enjoy ... there are no secret codes. Have fun with them.The Changing World of Radio Regulations
Industry Canada's interpretation of the radio regulations are always kept in mind. As a club we push the limits of these regulations as much as possible to open up new areas for exploration. Rules and regulations are meant to change as society evolves. A bit of harmless "civil disobedience" can often accelerate change. Forcing an issue to court ... such as building a radio tower in defiance of municipal laws ... is quite often an important first step in accelerating legal reformation.The Radio Amateurs of Canada (RAC) are always working to reform our radio regulations and to protect our radio spectrum. Far too few amateurs are members of our group. Check out their website at http://www.rac.ca/ ...
Radio Breakfast Meeting Saturdays
A breakfast meeting is open to all that are interested in radio. It happens at the Kitties Hideaway (near Mayfair Mall on Douglas St.) at the back of the Vacation Inn at 7:30 AM and sometimes also at 9:30 AM on Saturdays. This is not a club activity ... we are just announcing it here. It is a fun social event and it gets announced on some of the local club repeater systems. All are welcome from the CB, Amateur radio and scanner community.
Current Projects
Low Frequency Band (1 to 200 khz)
Experimentation in the low frequency bands are underway. This rarely used part of the radio spectrum has recently been demonstrated to allow for communication across the Atlantic. We are only just starting to experiment in this area as of December 2001.The club has applied for a 1 year experimental licence to work within 1-200 khz. Currently this is not part of the ham bands but through our club efforts and the work of the RAC we should be able to establish amateur radio allocations within this part of the radio spectrum.
Many construction ideas are offered through the Radio Society of Great Britain's low frequency pages.
The RSGB site is highly recommended as a source of circuit diagrams.Several members of our club program microcontrollers for industrial applications. It is apparent that LF frequencies can be achieved using Microchip microcontrollers, thus providing a simple way to synthesize these frequencies. In addition simple phase locked loop chips which are intended for audio frequency detection can be applied to LF operation. Equipment is very cheap and easy to build. A typical transmitter can cost as little as $10.
IRLP Neigborhood Simplex Nodes
The IRLP system, invented by David Cameron of Vancouver, was originally designed with simplex operation in mind. We are building this kind of system because it is suitable for neighborhood IRLP nodes, being cheap and easy to build. Several other neighborhood IRLP nodes similar to the node 117 on 147.585 Mhz are under construction, 2 more for 2 meters and others are planned for higher and lower frequencies.Through the construction of neighborhood nodes, a number of hams can work IRLP at the same time. ... Kind of like an HF radio for each part of town. The cost of an IRLP node is about $200 each plus the sharing of someone's high speed internet at their house. Medium scan TV is planned for international transmissions between Victoria and other IRLP nodes. A special node would be reserved for TV and would be on a 70cm frequency.
Several members are interested in building neighborhood IRLP nodes on HF frequencies. This would allow people on 2M to call into the node and attempt to make contacts on the HF band. This is probably the simplest approach to a 2m to 10m cross band simplex mode repeater and can make use of the existing IRLP node 1170 on 146.54 Mhz.
A cross band repeater / IRLP system offering full duplex operation is in the planning stages. Theoretically IRLP supports full duplex but is rarely used in this mode. This would allow full duplex cross band radios to make telephone quality connections between neighborhoods.
Classes in IRLP Node Building
During the spring of 2002 the club will be offering classes to help other hams build their own IRLP nodes. With a minimal knowledge of computers and some help in setting up their node many people will find it easy to maintain their own system. The cost to build your own node is equal to the cost of an old 2M radio, an old computer (100Mhz 486 minimum with 32 meg RAM) plus the $160 kit that is purchased through the IRLP site at www.irlp.net and is well within the budget of any amateur. You need to be on line with high speed internet.IRLP Micro Node Construction
Node 1520 in Victoria BC was constructed using the RadioShack HTX-404 handheld. This radio offers CTCSS and will put out 5 watts on high power. Both the HTX-202 and HTX-404 radios have been used for 100% duty cycle on high power with the addition of a low speed power supply fan blowing directly on the back of the radio. The all aluminum backed radio is ideal for this purpose.COS or Carrier Operated Squelch is required for IRLP operation. Wiring for HTX-404 and HTX-202 Handhelds was found by experimentation and below are the diagrams for doing it.
For our antenna on UHF we used TV flat lead for both the antenna and for the transmission line. If both ends of the flat lead are perfectly matched for 300 ohms there is less than 2db loss at 400 mhz over 50 feet. We used a folded dipole for the antenna mounted vertically and we used a 1/2 wave piece of 75 ohm tv shielded cable as a balun to bring the 300 ohm line down to 75 ohms. We ignored the slight mismatch and used an adaptor to connect to the BNC on the radio. The resulting system can be worked from 4 kilometers with a handheld running only 50 milliwatts. The purpose of the node was to talk on the IRLP while fishing several kilometers from the house out on the Pacific Ocean.
HTX-404 / HTX-202 showing white wire COS connection
(Used on Node 1520)
HTX-404 / HTX-202 Closeup of Cos Line
Ericcson PMH45A Commercial Radio for IRLP/ EQSO / Echo Link
The Ericcson PMH45A Commercial Radio is easy to find for free because it is wide bandwidth FM and commercial radio has gone to narrow band. The beauty of the radio is its signal processing and auto squelch with CTCSS. It puts out 40 watts. We found that you can turn it down with the pot closest to the output to 30 watts. With a small fan mounted behind it the radio does not even get slightly warm running 100% duty cycle at 30 watts for hours. The radio is highly recommended for tone quality and immunity to the most severe interference. When the radios were new (6 years ago) they cost $1500 or more depending on features. Now you will find them as cast off industrial junk.
The option connector, which is located conveniently beside a rubber grommlet covered hole in the case allows you to get access to the other lines for IRLP use. Make sure to use non polarized 1/2 microfarad capacitors to decouple the Speaker and Microphone lines. These lines carry a high current 13.8 volt source on them and the capacitor will protect your computer from these voltages.
The option connector pins are ...
PTT = pin 7 If PTT is shorted to ground the radio will transmit.
Speaker = pin 3 (Caution, must use decoupling 0.47 uF cap. to stop 13.8V power signal.)
Microphone = pin 4 (Caution, must use decoupling 0.47 uF cap. to stop 13.8V power signal.)Nodes 1170 and 1845 are now running this type of radio. One of the things that makes these radios a challenge to use for IRLP is that the Carrrier Operated Squelch line does not come out of the radio. The Victoria Communications Club studied the shop manual for the radio and found something even better ... the Tone Operated Squelch line. This allows you to have CTCSS active for an IRLP node. If you do not have CTCSS programmed into the radio, the same line becomes a COS line.
It is easy to tap into the TOS line using wirewrap wire and a small soldering iron. The radio is surface mount, so you have to use very low heat or you will end up removing the part that you are trying to attach the wirewrap wire to. We have converted 3 radios so far and are converting 3 more for IRLP / Eqso applications
Ericcson PMH45A Commercial Radio Cos Line Diagram
(Used on IRLP nodes 1170 and 1845)
EQSO internet linking
EQSO is another linking system that runs on Windows and links amateur radios to the internet. Click below to Build your own eQSO node for $7 and an old 2M radio.
Our First Commercial Product
The RatTail Antenna Booster will improve the effective radiated power of most handhelds by 400% as measured at a distance of 2 km. This will double the range of a handheld 2M radio, marine radio, or aircraft handheld. It is patented in 2002 by 3 club members and is marketed through Microsec R&D. Click on the picture below to go to look at our product. The profits are shared by those inventors in the club who worked on its development according to the work and investment by each of them.
The IRLP is spreading to other star systems
... To boldly go where no Node has gone before!
(Malcolm Scrimger, VE7DAO)
Two IRLP Students, Ferrengi on the left and Romulan on the right.
The Aliens were visiting Quarks Bar and Restaurant, Las Vegas.Contact us and please include VCClub in your subject area.
Ian Soutar (VE7DJI) Vancouver Island Canada
IRLP Node 1520
Have fun experimenting
... give us a call if you need help
... or get together for coffee and chat.
Meeting 1st Thurday of each month
at 7:30 PM
Links of Interest
RadioZone of Victoria
Famous Inventions
The Victoria Communications Club is an RAC Affiliated Club
last updated on 13th March 2004
