Model Yachting Resource News has been in existence for one year – it has been fun! The goal is to still provide information about model boating. This means giving the chance for individuals to write and read information on model boating. Sometimes the information does not have universal appeal and sometimes it does. Again, the goal is to provide information about the hobby of model boating, which hopefully creates new thought and ideas to enjoy the hobby more.

The new International Sailing Federation 2005 – 2008 Sailing Rules are now available! In this issue we’ll start looking at the new rules to better the understanding them and to avoid problems. Of all of the things that can go wrong at the pond, it is arguments are over the rules. Everyone knows the rules make the playing field level and make the event equal, but some may not want go along with that. So the results are an exchange of ill words that can create more harm than good.

I have always supported the ISAF rules. I think teaching the ISAF rules should be one of the top items at each club so club’s members will know and understand the rules. Many times I have heard negative comments at the pond that had a direct relationship to not knowing and following the rules. Again, the solution is simple: all participants should to be willing follow the rules all of the times, no matter what.

At no time am I saying this will be easy. There will be a few who will choose not to follow the rules or want to use their own rules. When everyone knows events will be ran where ISAF rules are being enforced, there will be few if any problems. Fully understanding the rules is not easy, even season veterans can make mistakes, no one is perfect. But if an honest attempt is made to follow the ISAF rules, protests can be taken care of without any issues. All it takes is for everyone participating in a event to follow the rules. Doing so will make the event remembered for being fun and not for the problems. _/)

For you rule junkies, the new International Sailing Federation (ISAF) 2005 – 2008 Sailing Rules are now available on the Internet! They can be downloaded from the ISAF Rules & Regulation Page - www.sailing.org. Before the new rules hit the press, ISAF has made them available six months early to give all interested parties time to go over the rules and get familiar with the changes before they go into effect on January 1, 2005.

One problem with the sailing rules is individuals new to the hobby/sport find it difficult competing in a model sailboat race. The reason is they don’t know the rules well enough to keep out of trouble, and they don’t know their rights. There are a lot of rules to know and understand. To help new skippers learn the ISAF rules faster, some clubs provide a watered down sheet of the main rules. This way new skippers can start learning the rules one step at a time. Once new skippers have learned those rules they can learn more as time goes on.

To some people, the idea of giving a shorten list of the rules to new skippers is heresy and anyone with the idea needs to be stoned. One comment to counter act this thought is when season veterans are racing with newbes (people new to something), veterans love to hold the new skipper’s feet to the fire when it comes to the rules.

The best thing for clubs to do is to have ISAF rules training for anyone that wants or need it. The time to hold rules training is before events, not during the event. If enough time is spent going over the rules, the better the chances there will be fewer problems during race day. This brings up another idea that has been kicked around to help understand the rules.

When reading the official ISAF rules book, most model yachters have to wade through a lot of rules that don’t apply to model yachting, and have to refer to Appendix E for rules that only pertain to model yachting. Would it be interesting if ISAF or AMYA come up with an ISAF rulebook that is only for model yachting? Think about it, an ISAF rulebook only for model yachting that only has rules that pertain to model sailboat racing. The rulebook would have all of the word changes, deletions, and additions from Appendix E, and not have all of the rules that model sailing don’t use. This way newbes and veterans to model yachting can read and understand only the rules that apply to the hobby/sport. Who knows, maybe someday the idea may come about.

While I am on rule books, Dave Perry’s Understanding the Racing Rules Through 2008, a companion book to ISAF’s The Rules of Racing, is currently being produced and will be available sometime at the end of the year. If any book that helps explained the rules of racing, Perry’s is one of the best. Do yourself a favor, when this book comes out, buy it and read it. You will be glad you did. _/)

by Karen Barnett

So, at your club meeting, word of an impending event has everyone talking. Do you speak up and volunteer to take care of part of it, or do you kick back, look around and just see what everyone else does? Some folks think if they raise their hand for an instant, all their free time for the next six months will be gone. They may be right, if too many people depend on too few to get the job done.

Anyone can be a critic, and professionally, critics have their place in society - to review movies, books, or art. In a club, critics can be very harmful. What I say to members that point out a "problem" with the club, is "what are you going to do about it?" A club needs to operate in some ways like a job, but folks mistake the two. For one, its a non paid position, so all that extra time and energy needed to do these changes needs to be done by someone who has a personal interest in the results- it's really a donation to the cause. When a club member feels imposed on or criticized without help to change the problem, the club is going to have major problems. It’s likely that person is doing more than their share, anyway. Now when that person quits the club in frustration, everyone wonders "what happened to him or her?" Some folks need the money motivation to take something seriously - like a paycheck or perks but in a non-profit club, you need to raise the money to sufficiently put on the type event you want, but no more, other than the occasional donut. One motivation for getting things done on time and done well is knowing you can put on a far larger and more elaborate show with a group or club than you can by yourself. You will be known in your community associated with your group name, to whatever extent you want to make the effort.

Getting everyone involved with planning and putting on events keeps everything from falling on just one person. Some key items overlooked at events can cause lots of hassles and take very little time to do well. Knowing Tom is going to be there at 5 a.m. to block off the parking lot, and Paula and Don with the repainted signs at 6 a.m. is a very reassuring thought for a club president, event coordinator, or anyone who cares how smoothly an event goes. Dividing the event into parts, times, or areas among the club members makes sure there is time for everyone to eat and "take five" throughout the day. Knowing some people can't spend the day, but have the time to make a few phone calls, come early to set up, or put in an hour at the registration. It all helps put on a well-run show.

Each time a club puts on an event, it should take less time to organize, and people usually gravitate to the type help they like to do. Its the club organizers job to delegate, but it's everyone pitching in and getting things done, and people having solutions and optimism that keeps away burnout.

Editor’s Note: One problem with getting club members to help is some members become burned out after serving for the club. Another problem is some members do help out while others do nothing. It is like the Little Red Hen – no one is willing to lend a hand to help but always wants in on fun. _/)

by Max Feil

Stetson Flyers & Ottawa Remote Control Club

In the increasingly popular hobby of radio controlled model airplane flying, frequency congestion has prompted a series of changes over the years to allow more flyers to use the same frequency band. [Almost all of these changes apply to out RC Boating activities as well.] Today's dense frequency environment demands that extra precautions be taken to avoid interference problems, which in R/C flying can result not only in the loss of prized aircraft but personal injury or property damage as well.

I will attempt to explain in my own words the issues involved in trying to minimize both congestion and interference problems. I will start with some simple theory, and then apply this to the five main interference problems that can result with radio equipment that is in use today. The goal of this article is to stimulate discussion and increase understanding to allow the members of R/C clubs to update and improve their frequency rules to help provide a safe and enjoyable boating site.

First, some very general, oversimplified theory on radio interference causes. Keep in mind that I am not an RF engineer I am an electronics engineer. I am also trying to keep things as simple as possible for the average R/C modeler. If anybody wants some more detailed, technical information, I have a very good article sent to me by somebody who works in the radio industry that I can pass on to you.

When we talk about the frequency that an R/C radio system operates on, we really mean its "center frequency", since both the transmitter and receiver operate within a band of frequencies that is several kilohertz (kHz) wide. Your transmitter will transmit strongest at frequencies very close to its center frequency, with a decrease in signal strength as you move away from the center frequency. Similarly the receiver will be most sensitive to frequencies very close to its center frequency, with a decrease in sensitivity as you move away from the center frequency. Note that the center frequency of the receiver can be slightly different than the center frequency of the transmitter and things will still seem to work ok, but since power decreases as you move out from the center frequency, range will be reduced. Incidentally, this is why range checks are important. A bad range check may indicate that either the transmitter or receiver is out of tune, and their center frequencies no longer line up. A crystal change can produce the same effect. The radio must be fine-tuned afterwards to ensure that the transmitter and receiver are centered correctly, both with respect to each other and with respect to other radios.

The width of this band of frequencies around the center frequency is a major factor in determining the effects of radio interference. If your receiver encounters a second signal that is too close to its center frequency and the two bandwidths end up overlapping too much, then interference will result. The closer the interfering signal is to the receiver's center frequency, the less power is needed to cause interference. In the extreme case, if somebody turns on their transmitter and is on exactly the same frequency as you, you may loose control even if their signal is very weak, for example if their antenna is down or if they are sailing several miles away. Conversely, if somebody is operating on a frequency that is quite far away from the center frequency of your receiver, they can still interfere if their signal is strong enough. I will come back to this point later.

If this was the only way that interference could result, life would be simple. However there are several other RF interference mechanisms and they are much less obvious.

Pretty well all receivers convert the signals they receive to lower "intermediate" frequencies through the use of one or more special internally generated frequencies. The principle is called "heterodyning" and it involves mixing the received signal with locally generated frequencies in one or more stages. Receivers with one stage are called "single conversion" and almost always use an intermediate frequency (IF) of 455 kHz. Receivers with two stages are called "dual conversion" and usually use a first IF of 10.7 MHz and a second IF of 455 kHz. It is in the mixing process that several problems may be introduced which can result in unwanted signals showing up after conversion to the intermediate frequency. There are two main concepts here: "image frequency" and "distortion".

Each conversion stage in a receiver will have an image frequency. It will convert not only the desired signal down to the intermediate frequency, but also any signal that is twice the IF either above or below the desired signal, depending on the type of conversion being used (high side or low side). For example, if you are using a single conversion receiver, the image frequency will be 910 kHz (45.5 channels) away, either up or down (but not both). If another transmitter in the R/C band is operating at this frequency, you may experience interference. Note that image frequencies are not a problem for dual conversion receivers since at each stage they are far away from the desired signal and therefore easily filtered out beforehand.

The signal mixers that are used to perform frequency conversion in the receiver also introduce a certain amount of distortion. This results in the creation of extra frequencies called "harmonics" and "intermodulation products". Harmonics are simply signals at multiples of the desired or "fundamental" frequency. This is similar to what happens when you hit a piano key or pluck a guitar string. For example, if a radio frequency of 72.030 MHz is present, then distortion will create harmonics at 144.060 MHz (2 x fundamental), 216.090 MHz (3 x fundamental), etc. The power of each successive harmonic (2nd, 3rd, 4th, etc) is generally lower than the previous one. Luckily, harmonics are so far away from desired signals that they are easy to filter out. Intermodulation, on the other hand, is perhaps the most important concept of this article. It takes place when more than one radio frequency is present, and is defined as the production of sum and difference frequencies from the set of original frequencies present. For example, if two frequencies f1 and f2 are present, they will "intermodulate" and produce two additional frequencies f2 minus f1 and f1 plus f2. These are called the 2nd order intermodulation products (2IM).

To help illustrate this, I will point out an effect similar to intermodulation that is noticeable in everyday life. When two tuning forks of almost the same frequency are struck at the same time, a slow pulsating "beat frequency" is created which is quite audible. This is the difference frequency you are hearing. Anybody who plays guitar will also recognize that difference frequencies play a big part in being able to tune their instrument. Now let's go further and note that the 2nd order intermodulation (2IM) products combine further with the original frequencies to again create sum and difference frequencies that are the 3rd order intermodulation products (3IM). Luckily, with each successive order of intermodulation (2nd, 3rd, 4th, etc) the power of the signal decreases. As an example, consider two people flying, one on channel 44 (72.670 MHz) the other on channel 40 (72.590 MHz). The sum and difference frequencies created are 145.260 MHz and 80 kHz respectively. These are the 2IM frequencies, of which 80 kHz is the more important one. The 80 kHz signal recombines with the two original frequencies to produce new signals with frequencies of 72.590 - 80 = 72.510 MHz and 72.670 + 80 = 72.750 MHz. These are 3IM products, and note that they correspond to channels 36 and 48! They are usually not a big problem since the power of third order products is quite low. Also, newer receivers are quite good at keeping intermodulation products generated within themselves to a minimum.

Note that not all intermodulation products are created inside the receiver. Some intermodulation products are actually created within transmitters that are operated too close together. Transmitters will generate significant levels of intermodulation if they are closer than about 20 feet together.

So, now we have talked about the sources of interference for a receiver, namely a signal being too close to either the main frequency or the image frequency, and we have also talked about how various (perhaps unexpected) frequencies are generated both by transmitters and within the receiver through intermodulation distortion.

To lead up to a discussion of specific problems that need to be addressed at today's pond, I will start with a brief history of radios and radio frequencies in use in Canada and the U.S. I will concentrate on just the 72 MHz band, and ignore the 27 MHz (CB) band, the 50/53 MHz ham frequencies, and the 75 MHz surface frequencies.

In the past, the R/C spectrum was not as crowded as it is today. Most R/C activity was restricted to an original set of 6 frequencies which were specified not using channel numbers, but by using a two-color flag system. Purple/white was 72.320 MHz, red/white was 72.240 MHz, etc. These channels were no closer than 80 kHz together, and the original radios were designed around this 80 kHz spacing and used single conversion receivers. In fact, in Canada many of these radios are still in use today, which is why many Canadian R/C clubs, including the Stetson Flyers and the Ottawa Remote Control Club still follow 80 kHz spacing rules on their frequency boards through the use of a 5-pin wide system. The next step, which took effect in 1988, was the establishment of 50 R/C channels, all 20 kHz apart, starting at channel 11 (72.010 MHz) and running to channel 60 (72.990 MHz). Note that the 6 old frequencies fall "in-between" these channels, and therefore are sometimes referred to as "channel 26 and a half" or "channel 22 and a half", etc. At first only even channel numbers were available, with odd channels slated for introduction in 1991. This meant a minimum possible spacing of 40 kHz.

In the several years between 1988 and 1991, radios were being sold that could handle a spacing of 40 kHz, and which were equipped mostly with single conversion receivers. Examples are the Futaba Conquest AM series, and the Futaba 5 channel PCM. Then, in preparation for 1991 and the introduction of the odd channels, these so-called "wide band" radios were phased out in favor of "narrow band" radios. The new 1991 radios being sold today need to handle 20 kHz spacing, and most have state-of-the-art dual conversion receivers. However even in the strict 1991 environment single conversion receivers are still being sold for some radios (for example the Futaba Attack AM series, and some JR receivers which have special circuitry called ABC&W - "Automatic Blocking Circuit with Window").

So we have seen a progression of radio models, basically in three categories based on their capabilities:

80 kHz spacing, single conversion rx, wide band tx.

40 kHz spacing, single conversion rx, wide band tx.

20 kHz spacing, single/dbl conversion rx, narrow band tx.

When we talk about a "narrow band" radio, we mean one that can handle 20 kHz spacing with multiple frequencies in use at the same time. Unfortunately not all 1991 radios come with true "narrow band" receivers, just narrow band ("gold stickered") transmitters. The idea is that the manufacturer attempts to ensure that you never shoot somebody else down. However if your receiver is not narrow band (i.e. not dual conversion or ABC&W), somebody with wide band equipment can still shoot you down. This is rather like the world of automobile insurance, where liability insurance is mandatory but collision insurance is optional.

There are still a fair number of radios in operation from category 1 (above), and many radios in operation from category 2.

Our goal is to make available as many R/C channels as possible while doing our best to ensure that no potential for interference exists. There will always be unanticipated factors such as radios out of tune and interference from external non-R/C signals, but we want to at least avoid known problems. We also want to explore all possible options before making rash hard-to-enforce decisions such as banning certain types of radio equipment or disallowing certain channels.

The following five problems must be handled:

We would like to use as narrow a spacing as possible, however two radios must not operate on frequencies closer than the spacing they are capable of handling. 20 kHz spacing (i.e one channel apart, for example one flier on channel 30 the other on 31) is only possible if both fliers have narrow band transmitters AND receivers. If one of the fliers has a wide band transmitter OR a wide band receiver, then the spacing must be wider, for example 40 kHz or 80 kHz.

Anybody using a single conversion receiver should ensure that no other transmitter is operating 910 kHz away. Luckily this affects only a few people since 910 kHz spans almost the whole 72 MHz band and since one transmitter would have to be on an old half frequency. The only radios likely to be affected (in order from most likely to least likely) are those on channels 14.5 (brown/white), 58.5 (yellow/white), 60, and 13.

No two radios should operate on frequencies such that their difference is too close to the intermediate frequency of any single conversion receivers being used. For example, if somebody is on channel 42, and somebody else is on channel 19 the difference frequency is 460 kHz, which is very close to 455 kHz. This could affect EVERY single conversion receiver in the air. They could all crash no matter what channel they are on. Fortunately, not all single conversion receivers seem to be affected since 460 kHz is not right on 455 kHz, and since they have varying abilities to suppress unwanted distortion. Receivers from radios in categories 1 and 2 (above) will tend to be more affected. (I had one crash and one near crash due to 23 channel 2IM with my Futaba 5 channel PCM that I bought in 1988.) There is no easy way of telling which single conversion receivers are more susceptible than others. The only sure way to avoid this problem if we don't incorporate it into the frequency board is for EVERYBODY to use only dual conversion receivers, but this would obsolete at least 50% of the radios out there. Note that the main reason a dual conversion receiver is not affected by 2IM is that all direct sum and difference frequencies that can be created in the 72 MHz band fall either way below or way above 10.7 MHz. Also note that this is a recent problem. Before the introduction of the odd channels, THIS COULD NOT HAPPEN. Two even channels can never be an odd number of channels apart (23).

While not a big problem, 3IM is still an issue, as it has always been. The best protection for this problem is to ensure that people always stand in their pilot's box when flying so that no two transmitters with their antennas up come closer than 15-20 feet to each other. This is because those intermodulation products that are created within transmitters increase in power if the two sources are close together. Another rule to keep in mind is not to walk too close to somebody else if both your antennas are up.

This problem is quite common. If two boaters are standing relatively far apart, say at opposite ends of the lake, and the first person runs their boat too close to the second person, the second person's radio signal will be so much stronger than the intended signal that the first person's receiver may experience a short burst of interference. This is in keeping with the discussion earlier which explained that an interfering signal need not be close in frequency if it is very strong.

Well, I've said almost all I can. The next step is to design an improved frequency board and/or modify club rules. I will now very briefly list some of the solutions that I have heard other clubs put in effect:

1. Ban odd channels.
2. Allow the use of dual conversion receivers only.
3. Go to a special pin system that forces you to take all necessary pins, for example the pin(s) for channel(s) that are 23 channels away.
4. Go to a special computerized frequency board where the computer decides whether you can fly based on rules similar to those listed earlier.

In conclusion, there are some basic principles involved in radio interference, and these result in about 5 main problems that a frequency board and field layout must overcome. The first and third listed above, namely spacing and 2IM, are the most pressing, especially with the introduction of the new odd channels in 1991.

I have not dealt specifically with interference from non-RC sources, for example pagers (a problem in the U.S.), 2IM from audio of TV channel 4, etc. This type of interference will follow the same basic principles as I stated in the body of the article, but will be unique to a particular site and will require local rules. _/)

Recently, a local club’s newsletter called the "Poop Deck" had a reader send in a question on what is a poop deck. The newsletter’s character "Mort" answered the question. A poop deck is the bridge deck where the captain hangs out and it is where you go to go. At first the answer looked right but after remembering a History Channel show on square rigged sailing ships, I took a second look.

After doing some research on the Internet, the following was found to further explain what the poop deck is. "A poop is a raised deck at the stern of a vessel. Its original intent was to help guard the rear end of a ship from being swamped by large waves coming from astern. Above and astern of the quarterdeck is the poop deck, above the Captain's quarters. The name came from the Middle English poupe, from the Latin puppim, meaning the rear section of a ship. The word derived from the Latin Puppis, meaning a doll or small image. The Romans and other ancient seafaring peoples had a small sacred idol or image affixed to the stern. From the poop deck the officers took navigational sightings and directed the flying of signal flags. During battle, the Captain directed the action from either the poop or quarter decks." - www.geocities.com/starheavens_2000/navigating.htm. So, the poop deck being a place where the captain hung out was correct, but it being a place to go [for relief] needed more research.

Again, I went to the Internet to find the location of the bathroom on square rigged sailing ships. The nautical term for bathroom is the "Head". The head is the uppermost or forward-most part of a ship. In the age of sail, the crew was quartered forward in the forecastle, and the ship’s latrine or head was on the beakhead, overhanging the water – www.desertanchor.com/glossary.htm. Since toilet paper was not yet invented, good vigorous wave action took care of the problem. A side note, on old sailing ships with the aid of a scupper (a drain for the weather deck), there were spots for relief used by particular rank of the men.

So there it is, the poop deck is at the stern of the ship where the captain was, and the head is the latrine and is located at the forward part of the ship. With that, you now have the poop on the information. _/)

Almost every day you hear in the local news about the West Nile Virus in Arizona. What makes this so important, Arizona, primarily Maricopa County has had the most cases of West Nile Virus in humans in the U.S.! According to the state health officials, there have been 232 cases (as of July 30), of human infection with two deaths from this virus.

To help prevent the further spread of the disease, get rid of standing water around your home. This will stop mosquitoes from laying their eggs. To further aid in prevention of mosquitoes laying eggs, get rid of items that hold water. If there is nothing around your home to hold standing water, there will be fewer areas were mosquitoes can live.

Apply insect repellent that contains DEET (N, N-diethyl-metatoluamide) to exposed skin and to your clothes. The hours from dusk to dawn are the biting times for mosquitoes, so wear clothing that covers your body, and use repellent. Also, report dead birds to the local health department. It may be a sign that the West Nile Virus in your area.

Simple precautions can help lower the chance a person from getting the West Nile Virus. The next few of months are prime time for these little blood suckers, so use insect repellant that has DEET in it when you are outside having fun. _/)

Here is a nice shot of a 36/600 model yacht owned by George Baldacchino of Tempe, Arizona. _/)