Harold's Islander Project

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I have achieved 15.6 miles of range using an open half wave dipole antenna, which was elevated at a height of 45 feet.

With that range, my Islander is telling the truth! It really amazed me when I experience a distance that far... Harold

I am glad to see that you, Sir Harold, took the time and patience to have your 7 Watt FM Transmitter (The Islander) turn out so successful! It is truly outstanding that your time (in which you relentlessly labored in all of your experiments) and patience (which was needed in order to have the necessary time involved in pursuing the journey) showed through in the end! Now you have your own little jem...which will shine its' light for you throughout the many years! ! !

P.S. Your testimony (below) will surely give encouragement to those visitors who stop by the website and decide to venture out and make thier own Islander...or the Islander Jr...as you call it!

Below is Sir Harold's own testimony of his dedicated, yet demanding, journey with his own...

~ Islander ~

This webpage is dedicated to all viewers and hobbiest...especially to my dear good friend Sir Patrick.

Hi! My name is Harold and I'm from the Philippines. FM transmitters are one of my most ideal projects. I've built several kinds of FM transmitters, including video transmitters, but the range was not so good. Until I had searched the web and found Sir Patricks' website.

I was amazed with the contents of the site and learned so much information about the project. Actually, I'm up to the long range and more watts of power. I started writing him (Sir Patrick) and he always helped me throughout the project. I followed all of his instructions and suggestions...the result...3 thumbs up! It worked very well.

After so many days, weeks and even months of working with the unit, I always learned from my mistakes and he taught me a lot. And YES, the unit really works!

The above photograph is my finished 'Islander'! Just click on the picture for a more detailed view.

In order to capture good results, you should read first carefully, all the information and instructions stated in his website. If you have any question(s), even if it is a stupid question regarding this matter, do not hesitate to e-mail him (or me). I mean any question that you would like to ask, regarding his transmitters. He will surely answer it very well. Just be honest and true to yourself, then you will succeed. And always...be patient in building such projects. Practice makes perfect ! ! !

Anyway, about my project... My 200mW unit, it turned into 250mW's of output power and a range of about 2 to 3.5 miles. I was using an open half wave dipole antenna and the height was 35 feet above ground. But the audio signal was weak. By the way, my dipole antenna was made of solid copper wires and it works great and it's long life.

Should the time come in making your 'open half-wave dipole' antenna...see how I made mine, together with erecting it on a very high pole. Just CLICK HERE for all the information...along with many pictures.

Remember, the foremost important criteria in generating a long-distance signal from any FM transmitter...is the height of the antenna itself !

You should build a homemade RF Probe Meter/Watt Meter and a Field Strength Meter. These 3 devices are very important in order to tune and get the output of your transmitter properly. You should also have an FM tuner for easy tuning at the right frequency.

About the coils...L1 and L2. I did not squeeze or stretch them. Instead, I only adjusted the 2 variable capacitors tuned at 87.9 MHz. My antenna is an open-end half wave dipole. Sir Patrick has complete instructions on how to make the dipole antenna using just only 2 coat hangers. I used 60 feet of RG-59 coax cable. The higher your antenna, the longer and better the transmission...please keep that in mind my friends. I also used an aluminum platform casing for my unit, including the power supply.

I also used a mono "female" jack for the input, if you like a microphone or just any audio devices you want to plug in. Another thing was, I used a 12 volt/3 amperes regulated power supply. And that's it. The circuit works very well and is very easy to build. But it takes time and patience to have a good and working unit.

TAKE NOTE: You must have a plastic tuning tool (jut like a screwdriver, but it needs to be plastic) for the variable capacitors and coils.

Before anything else, again, make sure you got the right polarities for your components especially the diodes and capacitors before plugging in your power supply. And make sure, your power supply is connected/mounted as close as possible to your unit.

First, in your 200mW unit, don't squeeze or stretch the coils (L1 and L2) after it was backed out of the bolt. Solder it as is! The 2 variable capacitors are the only thing to tune or to be adjusted. The antenna should be attached then, to the circuit. If you got an FM tuner which has a digital display for the frequency, that's perfect! If you don't have one, an ordinary FM radio will do.

Make sure to tune it to 87 or up to 87.9 MHz. Turn your transmitter to ON. Slowly adjust the 1st variable capacitor to capture the frequency, for example, 87.7 MHz. If you got it right and centered, adjust the 2nd variable capacitor slowly, it's for the amp or gain. The 1st variable capacitor and the first coil is the tank circuit or the oscillating circuit. That's where the frequency comes from. We all know that the main problem in our unit is tuning or capturing the main frequency. But you'll overcome this soon and you have lots of time to master it, so be patient and take your time my friends.

If you're content with its signal, measure it by using your home-made RF Probe/Watt Meter. Check the website for that new circuit. Read carefully all the instructions and study the formula. Or you can use the example given, as your guide. Speaking of the RF/Watt Meter, the unloaded output voltage (RF Probe meter mode) must be at least 12 volts dc. While the loaded output voltage (RF Watt Meter mode) must be at least 6 volts dc. This will surely give you more than 200mW of output power. Higher than those is great.

If you're not sure what you're doing, contact me or Sir Patrick. We'll be glad to help you. And of course, you should have a good dipole antenna. Learn to experiment and document all your results and ideas for future use. Use a calculator for the formulas and never give up. And lastly, you should have more stocks of parts and components (resistors, capacitors, diodes, etc.), just in case you break or burn your components. And lastly, when you're satisfied, make a distance or range test. Goodluck ! ! !

Well, this concludes the 200mW portion of the Islander. Please feel free to e-mail us. We'll be glad to help you out in building this wonderful 'gem'! Until then, as Sir Patrick always says..."KEEP THE FAITH".

OK, when you're successful in your 200mW unit, proceed to the last (3rd) stage which is the 7 Watt unit. We call it...The Islander !

Yes, I now have my newly made PCB for the Islander...which includes the 1st, 2nd and 3rd stage...all in one printed circuit board (PCB). When I did this, I was so confident that I can make it again this time and there it was, my dream came true.

First, my 200mW stage (I call it...The Islander Jr.) which later turned into a 327mW unit (without the Islander parts soldered). When I was satisfied with the results, I added the components for the Islander.

My Islander now is perfectly stable. Lots of modifications and additions were made. I'm using a dipole antenna made of aluminum tubes cut into exact measurements for 87.9 MHz. I also increased the height of my antenna, which is now 45 feet above ground and away from electrical or tall objects. It now has 75 feet of coax cable.

My unit, the Islander, was mounted on an aluminum platform casing together with the regulated power supply. I don't use a cover for it 'coz it's easy for me to adjust and change components. All the negative terminals of the unit were grounded to the casing, to reduce harmonics and/or unwanted spurious noise/sounds. And yes, time and focus on this project (if you don't have any priorities) is a must.

Tuning or working this beast is time demanding. Yes, it doesn't have any variable capacitors in this stage, only two pcs. of 3 turn coils are to be adjusted. First, in order to capture, again, the main frequency in this stage, you should stretch or somtimes squeeze the 1st coil which is "L3". I prefer stretching it, until you hear the audio coming from your input which is the mic or any audio signal. It MUST be a clear and static free audio signal. Don't do anything to the tank circuit (L1 and 1st variable cap). If you are to make the adjustments, only the 2nd variable cap is allowed. So now, we have 3 things to adjust, the 2nd variable cap, the coil L3 (last stage) and the coil L6 (last stage).

OOPS! Before I forget, you must have that VK200 choke coil installed or soldered (that's L4 on the diagram). Without it, the output power is less by some 20 to 25 percent). That's an important thing to have in this stage. Ok, then, after you capture the main frequency which is 87.7 or 87.9 MHz, adjust slowly the 2nd variable cap for audio clarity or gain. And don't forget to adjust L6 or the last coil of this stage. It's for the output wattage or also the gain. The higher its voltage (using the Watt Meter), the better.

Once you're done and contented, do the same thing with the RF Probe/Watt Meter. Measure its' output voltages and wattage. Unloaded output voltage must be at least 35 volts dc, while the loaded output voltage must be at least 25 volts. Higher than those is great, but not too much. Again, when you're satisfied with the results, do the range test. If you have a car with a car stereo and antenna, that's good. Tune it to your frequency, and when you hear a clear and static free signal, reset the distance meter gauge (if you have one) found on your dash board to 0 (zero). That's for you to know how many kilometers (kph) you're going. Of course, drive carefully!!! And be sure to have a paper and a pen to write down the results or the range. That's what I did.

Anyway, I followed all the layouts and diagrams exactly on Sir Patricks' website regarding the Islander. I soldered all the components nice and clean. If you're doing this, just take your time, don't be in a hurry.

And by the way, use a good heatsink and cooling fan for your 2SC1971 transistor. Frequency may change due to the temperature of the transistors especially the 2SC1971. Some adjustments again will be needed if there are some changes.

Notice the SO-239 socket for the coaxial cable in the lower left hand corner of my enclosure.

Should you decide to put the Islander in an enclosure, make sure that when the fan is installed...it is blowing the air 'out' of the

enclosure...NOT IN. This is the typical airflow found in most electronic devices. This way, the hot air is sucked OUT of the enclosure...therefore bringing in ambient air from outside the enclosure to cool the components.

Don't panic when you encounter no oscillation on your unit when you first turn ON the unit. This means that the transistors are warming up until it gets back to normal function. Wait for a couple of minutes when you turn ON your unit. If it's still not working, re-adjust the variable caps a little. It should work fine by then. Be patient and study or check all the routings of your copper layout before soldering. I've been there (trouble) before so I've learned my lessons, a lot!

Aside from that, I've soldered my antenna coax directly on the PCB, just like Sir Patrick does in his website. Later, I added a jack hook-up for easier attachment.After I've made everything, including measuring its' ouput voltages and wattage, the result was truly great. It works and of course, I got 6.9, maybe 7 watts of output power. And sometimes, 6.7 watts. I think this result is fine with me. I also admit that sometimes, I do re-adjust its gain and frequency (variable caps) for better audio/gain signal.

And also, always double-check your components if they are properly soldered or in the right polarities. Check...Check...Check... everything ! ! !

So, this (last) stage is very time demanding. You'll always have to observe and check your unit whenever you're using it. Based from my experience, concerning this project, it took me months, then weeks, then days before I finally made it and understood all the ways of making it. I've also learned to troubleshoot this project alone. 'Coz I've got all the tips and advices that Sir Patrick has given me. And once you succeed, I'm sure you'll agree with me and Sir Patrick, and things will also be easy for you. Take care guys and GOOD LUCK ! ! !...always, Harold.

~ ATTENTION ~

This is extremely important ! ALWAYS unplug or remove your antenna connection from your unit when it is NOT in use...especially when there is bad weather approaching.

LIGHTNING CAN STRIKE AT ANYTIME MY FRIENDS ! ! !

It will surely destroy or damage your unit...OR EVEN YOU ! ! !

Be very cautious at anytime !

YES, more pictures and updates will be added here, so stay TUNED ! ! ! I'll get a digital camera soon for my unit and stuffs.

My Islander is now in good working condition. I have achieved 15.6 miles of range using a 45 feet dipole antenna. With that range, my Islander is telling the truth! It really amazed me when I experience a distance that far ! ! !

Read the complete letter that I sent Sir Patrick, on September 25th, 2003...that special day 'The Islander' showed its' mighty power! Just CLICK HERE.

With the help of my best friend while driving his car on his way home for about 17 miles of range from my house, we easily tested the range of my Islander. I really had no time to check the distance that far so, I asked for some assistance from my friend. He tuned

it to 87.9 MHz to hear my signal. During that distance test, while he was driving and listening to my signal, we both had our cellphones and talking to each other while I'm adjusting my Islander for best transmission.

And we did it! When he finally made it home, he could still hear my signal. And by the way, I asked my friend what music I was playing...in case I would know if he was telling the truth or not. And yes, he was right about the music I was playing/transmitting... 15.6 miles indeed ! ! !

So, if you are trying to test the range for your Islander, I suggest you guys to try this kind of test just like I and my friend did. Be patient ! ! !

Up to now, my Islander is still in good condition. I've also added a simple audio mixer circuitry. Take notice in the above picture, there are 3 knobs in front of the metal casing of the Islander. That is so I could balance the left and right audio channels from my discman (although still mono).

If you want a true stereo output, use a 'stereo coder'. Also, audio mixers are somewhat useful (for me) so that, if you want to use a mic and music at the same time, that's possible. Those 3 knobs I've mentioned are for volume controls...and the middle knob is the balance control for the left and right audio output. You can still add another volume control or additional circuitry for the mic. Honestly, I do not want others to hear me...that's why I'm content with 'music only' for transmitting.

Here are some more pictures that I have decided to add to the webpage. Since I am getting very familiar with my new digital camera...a picture can surely represent a 'thousand words'. Each picture shows a particular area in the project, where attention must be adhered to...

This picture shows where the NTE342 is to be secured on the PCB. One nut and screw is needed. Make sure it is good and tight.

Just click on the picture to the left, to find out how I made my 'Simple Audio Mixer'.

I chose to use a 'jack' hook-up for the coaxial cable...which makes it a lot easier for attachment/detachement.

It is also mandatory that one uses a medium- sized computer fan, to keep the NTE342 transistor from getting too hot.

Notice the two black holes. This is for the U-bolt that is attached, to secure the antenna to the G.I. horizontal beam.

G.I. guide wire is needed to help give structural support to the G.I. horizontal beam. Otherwise, the beam would be 'too' side heavy.

OK, that would be all for now. I'll keep you updated anytime. Good luck to all of you ! ! !