View source for E-Z A.M. TO SHORTWAVE CONVERSION

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I put this package together to stimulate interest in listening to shortwave radio. Because so many people complain that a shortwave radio is expensive, the primary piece of this package is my simple and free conversion plans that will turn a standard AM (mediumwave) radio into a shortwave radio. IÕve also included a couple of FAQs I snagged off the Internet to answer any questions you might have. 

Please distribute this file as you like, but make sure that you attach my name and info to this file particular document. IÕd appreciate any comments or insights you might have, but donÕt forget that the newsgroups that the FAQs come from are great resources filled with people who can answer your questions.

Grant Barrett
232 East Second Street No. 4C
New York, New York 10009


FOR YOUR INFORMATIONÉ

     You should be aware that this conversion doesnÕt produce a magnificent piece of modern technology. It is rather crude. It will, however, serve as an excellent introductory tool, and even as a substitute shortwave radio in an emergency situation. 
    You should also be aware that: shortwave is not stereo; that it is often dominated by the goodwill or poor temper of solar cycles; that stations fade in and out from moment to moment, change frequencies regularly and can be heard for only part of the day; that static and interference are generally omnipresent. 
     But you should know that you can hear hundred of languages, live news from most major and minor nations, music of nearly every culture, amateur radio operators around the globe and enough religious broadcasts to melt your crucifix. Shortwave radio has been providing constant news to those in the know for decades, long before the advent of CNN and is a useful tool for exploring another country before touching its soil.
    I could try an explain how I think this works, but IÕll be frank: IÕm not exactly sure. IÕd encourage you to look it up for yourself; in my search for the answer I discovered a way to make a simple modification that converts an FM radio to receive the aircraft band (maybe weÕll do that later). Sidetracked, I thus left my search indefinitely.

WARNING: This is based on something I learned to do when I was 13 and fooling around in the back of an old radio. I did not unplug it. Because the radio was poorly grounded, I was mildly shocked, in the same way a cow up against an electric cattle fence is shocked (no permanent damage, I think). I stress that you take every precaution against the electricity. Your best bet is to use a hand-held radio. ItÕs easier, not dangerous and itÕs just as good. BE CAREFUL.


YOU NEED:

--- A small, easy-to-open AM (mediumwave) radio. 
      When choosing your radio to convert, a hand-held transistor radio is perfect. You can theoretically do this with any radio, but desktop or home stereo models are usually more difficult to get into, involve higher voltages and more sensitive parts. IÕve converted more than 20 radios in this way�, and have found that $5US childrenÕs radios with no FM band and a large, friendly thumb wheel for tuning work perfectly. You should avoid Walkmans and anything with a combo cassette player; they usually have inferior AM radios, small tuning wheels and a ridiculous number of screws to get at the part we need. Also, donÕt use anything with digital tuning.

--- Two pieces of 12 gauge or smaller insulated (or shellacked) wire, one 24 inches (60 cm) and one 48 inches (121 cm) or greater.
      Wire typically used in telephone switching boxes works great, but you can also use magnetic wire spooled off of an old motor. For the short wire, the smaller the gauge of the wire, the longer the piece should be. Remember that your wireÕs insulation should be good with no breaks or bare places, except for about an inch at each end

--- Tools.
      Usually a screwdriver at most. Will vary according to radio.


INSTRUCTIONS:

1. Disconnect the battery or any power source. REMEMBER, if you are using a model that plugs into the wall, you must unplug the radio at least ten minutes before you start to let any charge dissipate. You could get shocked or damage parts (yours and the radioÕs) if there is a charge left in a capacitor or some such part. Be careful.

2. Open the case and look for the tuning coil. The tuning coil is on an iron (ferrite) rod, dark in color with a matte exterior, usually cylindrical with flat ends, but often found with two flattened or beveled sides. The rod varies in length, but is easily recognized by the fine wire that is wrapped around it in the middle or at one end, usually on top of waxed paper. There is nothing else like it in the radio.

3. Loosen the rod in such a way as to remove it from the chassis, but so as to not disconnect the wires attached to it. Be careful, because these wires are difficult to reconnect without a soldering iron and there is usually not alot of slack in them. Sometimes the rod is held in place by wax, other times it is held in place by a plastic loop that is screwed to the circuit board. 

4. Starting at either end, wrap the short wire around the coil on the iron rod. Leave about four inches at either end free to dangle for now. The coil already there should be underneath your new coil. [On some radios, the coil is separated into two parts. Wrap your coil around both parts to start and later you can test for effects to see what happens if you wrap it around one or the other]. Each turn of your coil should touch the last, until you reach then end of the coil already on the rod. If you find that you cannot wrap the new coil around the old without covering some of the wires leading from the old coil, do so, but be careful not to damage them or short them.

5. Replace the coil, and refasten it.

6. Run the two free ends of your coil from the case. You can run them out holes in the speaker grill, apertures youÕve carved in the back or side, or slip them through the battery compartment. 

7. Close the case. Reconnect the battery or power. 

8. Connect the two free (and bare) ends of your coil and an end of the long wire in a simple twist. The long wire is now your antenna. You now have a shortwave radio.


THINGS TO REMEMBER: 

-Depending on how many turns you made, your tuning range will vary, but usually it covers from about 5 MHz to 15 MHz, more than enough for decent listening. 
-If you are unfamiliar with shortwave, know that it works best at night, particularly in the range mentioned above. 
-If there are strong or very close AM (mediumwave) transmitters nearby, they may bleed through. 
-There will be repetition when you tune down the band. That is, strong stations will image themselves in more than one place on your tuning dial. So if you have interference, keep tuning down the band to find a clearer image. Also, even though there is repetition, keep tuning to find other stations beyond the range of repetition. 


VARIATIONS:

-Try untwisting the two loops of your coil and connecting the antenna to them one at a time. You should notice that during the day one of these connections will boost your AM reception substantially (but may also overload the radio or allow strong stations to bleed excessively). The other connection will provide shortwave reception, but will shift the tuning range of the radio (compared to when both ends of the coil are attached to the antenna) and will allow AM stations to bleed through more.
-Try just wrapping part of the coil. May change the tuning range.
-Try fewer wire turns spread across the length of the old coil.
-Try a longer antenna. 
-Try grounding one of the ends of your coil to a fire escape, steam pipe or other huge metal object and attaching the other to your antenna.
-Try grounding your antenna. 
-Try a different gauge of wire for your coil. 
-Try connecting each end of your coil to each end of the antenna. 
-The variations are endless. Experiment!


________________________________________________
Grant Barrett 232 E. 2nd St. No. 4C New York New York 10009
barrett_grant@bah.com   8.23.94 
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[[Category:TV and Radio]]